The Commonwealth of Australia

 

FEDERAL HANDBOOK

 

PREPARED IN CONNECTION WITH THE  EIGHTY-FOURTH MEETING OF THE BRITISH ASSOCIATION FOR THE ADVANCEMENT OF SCIENCE

 

HELD IN AUSTRALIA,

 

AUGUST, 1914.

 

COMPILED UNDER THE AUTHORITY OF THE FEDERAL COUNCIL OF THE ASSOCIATION

 

EDITED BY G. H. KNIBBS, C.M.G., F.R.A.S., F.S.S.

 

PUBLISHED BY THE

 

COMMONWEALTH GOVERNMENT By Authority ; Albert J. Mullett. Government Printer, Melbourne.

 

 

PREFACE.

 

This Handbook, specially prepared for the use of members of the British Association for the Advancement of Science, at the Australian Meeting of 1914, contains a series of articles written by persons selected for that purpose by the Federal Council in Australia.

 

Editor.

Melbourne, March, 1914.

 

CHAPTER VIII.

ASTRONOMY AND GEODESY IN AUSTRALIA.

By Pietro Baracchi, F.R.A.S., Government Astronomer of Victoria.

 

 

SYNOPSIS

 

1. Astronomy.

 

Astronomical work done in Australia -

 

(a) By Navigators, Surveyors and Explorers, for Geographical Purposes.

 

(b) By the Permanent Government Observatories.

 

(c) By Amateur Astronomers.

 

(d) By Australian Expeditions on Special Astronomical Occasions.

 

(e) For the Determination of Australian Longitudes.

 

2. Geodesy.

 

(a) Trigonometrical Surveys of High Precision.

 

(b) Pendulum Observations.

 

List of References.

 

 

 

 

1. ASTRONOMY

 

 

(a) Astronomical work done by Navigators, Surveyors, etc., for Geographical Purposes.

 

Sir Thomas Brisbane laid the foundation of Australian astronomy in 1821, but the record of astronomical observations made on Australian soil commences half a century earlier; as is well known, Captain Cook was selected by the British Admiralty, chiefly for his astronomical qualifications, "to conduct his famous expedition to the islands of the Pacific for the purpose of observing the transit of Venus of 1769, which he successfully accomplished at Otaheite, after which he discovered and visited several islands in the Pacific, and eventually re-discovered New Zealand on the 6th October, 1769, and observed the transit of Mercury on 9th November, at a place on the north-east coast, now called Mercury Bay, and sailing north, on 31st March, 1770, he discovered New Holland, landed at Botany Bay, and (on 22nd August, 1770) took possession of the eastern coast of Australia in the name of Great Britain" (1).  

 

In regard to longitudes obtained by lunar distances. Cook wrote "This method of finding the longitude at sea can be depended upon to within half a degree. Which is a degree of accuracy more than sufficient for all nautical purposes."

 

From Captain Cook's astronomical observations made on Australian soil in 1770 was derived the first value on record of the longitude of Fort Macquarie, Sydney, viz., 151° 11' 32" east of Greenwich, which is almost identical with that determined by Flinders 33 years after (151° 11' 49").

 

Captain John Hunter and Lieutenant Bradley determined the longitude of Port Jackson by a series of lunar distances, observed between 14th March and 28th April, 1788 (Hunter's Historical Journal, pp. 87-88). On 17th August, 1788 "we began at this time to take equal altitudes for ascertaining the exact rate of the time keeper."

 

In June, 1792, Captain Hunter, in a letter to the Admiralty said "The advantage of being able to ascertain the ship's place in longitude by observations of the moon will be ever satisfactory, but more particularly through so vast a tract of sea, in which the error of the log may considerably accumulate."

 

(2) The " first fleet," commanded by Captain Phillip, which brought out from Great Britain the colonists who formed the first permanent settlement upon the Australian continent, arrived at Port Jackson in 1788. Colonel Collins tells us, "Among the buildings that were undertaken shortly after our arrival must be mentioned an observatory, which was marked out on the western point of the cove, to receive the astronomical instruments which had been sent out by the Board of Longitude, for the purpose of observing the comet which was expected to be seen about the end of this year (1788). The construction of this building was placed under the direction of Lieutenant Dawes, of the Marines who, having made this branch of science his peculiar study, was appointed by the Board of Longitude to make astronomical observations in this country."

 

The locality where this observatory is built is known as Dawes Point, and the structure is still there, though not used for astronomical purposes. This may be regarded as the first substantial observatory erected in Australia purely in the interests of astronomy.

 

The expected comet, however, was not seen, and nothing is known about Dawes' astronomical work at this Observatory, except the determination of its geographical co-ordinates, which are latitude 33° 52' 30" S., longitude 151° 19' 30". A transit instrument was sent to him by Maskelyne, the Astronomer Royal, in 1791.

 

In regard to this comet, Russell wrote (6) "The comet, for which all these preparations were made, was that which had been observed in 1532 and 1661, and which was generally expected to return about the end of 1788 or the beginning of 1789. It was one of the twenty-four which Dr. Halley had used in his celebrated investigations, in which he proved that comets were subject to the then law of gravitation, and like all other astronomical bodies, revolved about some centre. In 1776, Maskelyne pointed out that this comet would be affected by the major planets, and that for the investigation of this important matter, it was very desirable that it should be observed in the southern hemisphere where it would first be visible; hence the establishment of the Dawes Point Observatory."

 

In one of the papers by Captain P. P. King (2) is given, amongst the longitude results of several navigators, the value of the longitude found by Admiral Don Jose D'Espinosa while at Sydney on the ‘Corbetas Descubierta y Atrevida’. This value reduced to Fort Macquarie, is shown as 10h. 4m. 51.91s., which is within a fraction of a second of time of the latest accepted value, and is very probably nearer to the true value than that found by any other navigator.

 

For more than 30 years after Dawes' watches for the comet, the astronomical record rests entirely on navigators and explorers.

 

It was during this period that French expeditions were moving about in Australian waters, while surveys of the coast and explorations inland were being conducted by such nautical men as Bass, Flinders, Murray, and King, and the first explorers inland - Gregory, Blaxland, Evans, Oxley, Cunningham, Frazer, Hume, and others. Skilled astronomical observers, and even accomplished astronomers were to be found among these explorers, and the sun, the moon, the planets, and the stars were, no doubt, closely watched and employed by them for the determination of their geographical positions.

 

Flinders, who first circumnavigated Australia in 1801 on the Investigator, was indeed an enthusiastic and most accurate observer of the heavenly bodies. It was he who trained Sir John Franklin, then a midshipman on the Investigator, in astronomical work. John Crossley, of Greenwich Observatory, was appointed by the Admiralty as the astronomer of the expedition, but left the ship at the Cape of Good Hope, to return home invalided, and Flinders wrote to the authorities offering to undertake the astronomical work himself, with the help of his brother Lieutenant Sam W. Flinders, but the Admiralty sent out to him another astronomer – Inman - who accompanied Flinders during the latter part of the voyage (3). Inman, on his return to England, became Professor of Astronomy, at the Royal Naval College of Portsmouth.

 

The amount of Flinders' lunar observations is remarkable, both for its fine quality and its large quantity. His value of the longitude of Fort Macquarie (Sydney), "151° 11’ 49"" east of Greenwich, is probably within one mile of the true value which, considering the instrumental limitations and the inaccuracy of the lunar tables in his day, may well be accepted as a result of the highest accuracy attainable at the time. In his ‘Voyage to Terra Australis’, are given the geographical co-ordinates of many places on the south coast of Australia (Vol. I., 1814), App., page 259.

 

(2) Lieutenant (afterwards Admiral) P. P. King, son of Governor King, arrived at Port Jackson in September, 1817. He had been sent by the British Government to complete the surveys of the coast of New South Wales, which, then, extended from South Cape in Tasmania, latitude 43° 39' S. to Cape York, 10° 37' S.

 

He made four voyages, extending over four years, from 1817 to 1822, during which he determined the longitude and latitude of a large number of points on the coast.

 

The results of the survey were published in his work ‘A Narrative of a Survey of the Inter-tropical and Western Coasts of Australia’ (2 Vols., 8vo., London, 1847).

 

From 1826 to 1830 he was in command of two ships – ‘Adventure’ and ‘Beagle’ - conducting surveys on the southern coasts of South America. Shortly after, he retired from active service and settled in New South Wales, where for the rest of his life he continued to devote himself to scientific work, "during his residence at Dunhered, from 1832 to 1839, and at Tahlee, Port Stephens, to 1848, kept his observatory in full work with the transit and other instruments" (2).

 

The results of his astronomical work are contained in two papers which were printed "at his own private printing press, apparently for private distribution, a copy of each of which is in the possession of his family." and in another paper, containing the first five years observations at Tahlee, which was published in the Tasmanian Journal, No. 6, a copy of which is in the Sydney Observatory, with the remainder of the observations in MSS. In one of the two papers first mentioned are recorded "the observed transits of the moon and moon culminating stars over the meridian of Tahlee, Port Stephens, New South Wales, from 1843 to 1849, and the resulting longitudes from them. Also observations of eclipses of the sun and occultations of the fixed stars by the moon at the same place." The derived longitude of the station is 10h. 8m. 11s.

 

"The second paper gives a description of the instruments in the observatory and the observations for determining the latitude of Tahlee, 1841 to 1848. These observations were made with an altazimuth. Nearly 300 separate star observations for latitude are recorded, from which the latitude 32° 40' 17.74" is derived. Also a list of about one thousand places for which the geographical co-ordinates are given."

 

Admiral King published in addition eight papers in the Monthly Notices of the Royal Astronomical Society, "Four refer to comets, amongst others the great comet of 1843; one to an occultation of Jupiter and his Satellites; another to a lunar eclipse; another to a transit of Mercury; and the last to a solar eclipse" (2).

 

Sir James Ross' antarctic expedition arrived at Hobart (Tasmania), in August, 1840, in the ships ‘Erebus’ and ‘Terror’. Sir John Franklin was then Governor of that Colony.

 

A vigorous campaign for the acquisition of data in regard to the magnetic conditions of the globe was in course at the time, under the influence of Gauss and Sabine, and Sir James Ross established a magnetic station at Hobart, and also an astronomical observatory, where a transit instrument, an altazimuth, and astronomical clocks were permanently mounted. This station was placed in charge of Lieutenant Kay. Although terrestrial magnetism was the principal object, astronomical observations were systematically made and continued till 1854.

 

An elaborate investigation of the difference of longitude between Hobart and Port Macquarie (Sydney), Parramatta, and Cape of Good Hope, is included in the work of this observatory.

 

 

 

(b) Astronomical Work done in Australia by the Permanent Government Observatories.

 

 

The Parramatta Observatory, though originally a private establishment, became the property of the New South Wales Government, and is for this reason placed under this heading.

 

 

The Parramatta Observatory.

 

In 1821, Major-General Sir Thomas MacDougall Brisbane was appointed Governor of the colony of New South Wales. Throughout his career as a soldier he had always been devoted to astronomy, and as the southern heavens offered him almost a virgin field for exploration, he urged the British Government to supply him with means for establishing an observatory in the country he was being sent to govern, but having failed, he undertook to carry out the idea at his own cost. Accordingly he purchased instruments, books, and appliances, engaged two assistants, and immediately after their arrival in the colony, in November, 1821, a site was selected in close vicinity to his official residence at Parramatta, upon which a suitable building was quickly erected for the installation of the instruments, and by the following April the Parramatta Observatory was already in full working order.

 

The assistants were Carl Rumker, an accomplished astronomer who later became Director of the Hamburg Observatory, and James Dunlop, whose great natural abilities, especially mechanical, rendered his services particularly valuable in a place where no skilled instrument makers were available.

 

The instruments (4) "were a transit instrument by Troughton, of 3¾-inch aperture and 64-inch focal length; a 2-foot mural circle, with telescope of the same length, by the same maker; a 16-inch repeating circle, by Reichenbach; a 46-inch achromatic telescope, with equatorial motion and wire micrometer, by Banks; a clock, by Hardy, set to sidereal time; and another, by Breguet, showing mean time." Also two other clocks, by Grimaldi and Barraud; a box chronometer, by Dent ; and a pocket chronometer.

 

The programme of the Parramatta Observatory was principally the determination "of the position of stars down to the eighth magnitude, between the zenith of the observatory and the South Pole"(4).

 

The regular series of observations was commenced on 2nd May, 1822. At first Sir Thomas Brisbane and his two assistants worked together harmoniously and with great assiduity, but on 16th June, 1823, Rumker left the observatory, and from that date till December, 1825, the greater part of the observations were made by Dunlop.

 

In December, 1825, Sir Thomas Brisbane returned to England, and Dunlop followed him towards the end of the following year, after having continued the work at Parramatta Observatory till 2nd March, 1826, and completed a series of observations of 621 nebulae and clusters, at his private house, with a reflecting telescope, 9 inches aperture and 9-feet focal length (2) made by himself (5), and a catalogue of 253 double and triple stars which he observed during the same period (5).

 

The records of the observations made at Parramatta with the transit instrument and the mural circle, from 2nd May, 1822, to 2nd March, 1826, were placed in the hands of Mr. Richardson, of the Greenwich Observatory, in 1830 "by order of the Honorable the Lords Commissioners of the Admiralty, who directed him to reduce the observations and construct a catalogue of the positions of the stars" the result being the well-known Parramatta Catalogue of 7,385 Stars for the Epoch 1825, published in 1835.

 

The re-discovery of Encke's comet at its first predicted return may be justly regarded as one of the brilliant records in the history of the Parramatta Observatory. The comet was re-discovered by Rumker on 2nd June, 1822.

 

After the departure of Sir Thomas Brisbane, the observatory was taken over by the Colonial Government, on payment of the full cost of its equipment, to the owner, and placed in charge of Rumker, who became the official astronomer, and resumed work in May, 1826, after having, on 15th July, 1824, discovered a new comet - I 1824 - which bears his name (10). He made many observations for latitude and longitude, and observations of the moon, the planets, and comets. The results are published in the Philosophical Transactions of the Royal Society, 1829, Part III., and in the Memoirs of the R.A.S., Vol. III. ; also in Vol. I. of the Monthly Notices. At the end of the year 1828, he went to Europe, and some time after became Director of the Hamburg Observatory.

 

The Parramatta Observatory remained inoperative for nearly three years. In 1831, Dunlop returned to Australia, and was appointed Superintendent of the Parramatta Observatory, which position he held till 1847.

 

Most of the work done by Dunlop during this period still remains unpublished. It is contained in eight books MSS., which were transferred to the present Sydney Observatory (2).

 

(7) On 30th September, 1833, Dunlop discovered a comet, and on the 19th of March, 1831, he independently discovered another, which had been first seen by Gambart, at Marseilles, twelve days before (8).

 

The observations of these comets are published in Memoirs of the Royal Astronomical Society, Vol. 8, page 251 et seq.

 

The Catalogue of 629 Southern Nebulae and Clusters, observed by Dunlop, in 1828, with a 9-inch reflecting telescope of his own make, as previously mentioned, was presented to the Royal Society, and printed in the Transactions of 1828, pp. 113 and 152, and the Catalogue of 253 Double Stars, observed in the same year, was published in the Memoirs of the R.A.S., Vol. III.

 

After Dunlop's resignation, the observatory was dismantled, the instruments packed and stored, and Australia remained without an astronomical observatory for several years.

 

In 1880, when the building which had once been the Parramatta Observatory was reduced to ruin, fast disappearing, the Government was induced to erect a permanent monument to indicate the site of the observatory.

 

Exactly in the position occupied by the transit instrument, a marble obelisk now stands, with the following inscription :- "An Astronomical Observatory was founded here May 2nd, 1822, by Sir Thomas MacDougall Brisbane, K.C.B., F.R.S., Governor of New South Wales" (6).

 

The geographical co-ordinates of this historical point, assigned to it by Rumker, are Latitude 33° 48' 50.68”, Longitude 101° 4' 6.25"

 

Although the admitted imperfections of Sir Thomas Brisbane's astronomical equipment, and his desire to accumulate data from direct observation at very high speed must be recognised as the concurring causes which prevented a degree of accuracy equal to modern needs to be attained in the Parramatta Catalogue - which represents the main results of Sir Thomas Brisbane's enterprise - thus reducing to some extent the value of the work done by him and his assistants, we must nevertheless regard that enterprise with profound admiration and look upon the obelisk now standing on the spot where Sir Thomas Brisbane, Rumker, and Dunlop observed the stars crossing the meridian of Parramatta, as the monument raised by an appreciative generation to commemorate the foundation of Australian astronomy.

 

The founder of the Parramatta Observatory and its successive directors were indeed held in high estimation in England.

 

The Royal Astronomical Society presented its gold medal to Sir Thomas Brisbane and James Dunlop on 8th February, 1828, and to Carl Rumker on 10th February, 1854.

 

 

The Sydney Observatory

 

This observatory is situated on one of the headlands projecting into the Harbor, on the western side of Sydney Cove, less than half a mile from Dawes Point, where Lieutenant Dawes erected the first Australian observatory, in the year 1788. The locality is now called Flagstaff Hill.

 

Through the persistent recommendations of Sir William Denison, Governor of New South Wales, soon after his arrival in Australia, on 20th January, 1855 (6), the Colonial Government voted a sum of £7,000 for the erection of an observatory in Sydney, and made provisions for the salary of an astronomer and a computer.

 

The Reverend W. Scott, M.A., was selected by the Astronomer Royal, Sir George Airy, to fill the position of first director of the proposed Sydney Observatory.

 

The first duty of Mr. Scott after his arrival was, as he relates himself, "to fix on a site for the proposed observatory. For purely astronomical purposes I should have preferred a position further inland, but as it appeared desirable for various reasons that the observatory should be in the immediate neighbourhood of Sydney, I could find no spot more suitable than that recommended by the Governor on which the observatory now stands."

 

The building was commenced in May, 1857 and was so far advanced as to admit of meridian observations being made in June, 1858."

 

The first astronomical equipment of the Sydney Observatory consisted of the instruments purchased by the Government from Sir Thomas Brisbane. In addition, a complete time-ball apparatus was installed. By means of this apparatus the ball on the tower was automatically dropped, at first at the instant of local noon, and later at the instant of 1 p.m. It was chiefly the practical value of this service which gave the Government sufficient inducement to establish the observatory and, at the same time, imposed the essential conditions in the selection of the site.

 

The work of the observatory was confined in the first instance to the approximate determination of the sidereal and thence the mean time by a number of nightly observations of clock stars (9).

 

The transit circle by Jones, with which Dunlop had in his later years made a few observations at Parramatta, had been sent to England to be remodelled and improved by Troughton, and did not arrive back till December, 1858. This instrument has an object glass of 3¾ inches aperture and 62 inches focal length. Its circle is 42 inches in diameter, divided to every 5' and read by four microscopes 90° apart. It was completely set up and ready for use in June, 1859.

 

Mr. Scott complains that this instrument was not entirely satisfactory. He says (9), "The instrumental errors are such that although the circle may be regarded for some purposes as an useful instrument yet it cannot be classed amongst instruments of the highest order."

 

(6) "It was a fortunate circumstance that just then, in October, 1858, the great comet of Donati, one of the finest in the century appeared in our southern sky, "for it served the purpose of drawing the attention of the authorities to the want of a suitable instrument at the Official Observatory for the observations of the comet and of obtaining from Parliament a sum of £800 with which an achromatic telescope, 7¼-inch aperture and 124 inches focal length, made by the celebrated firm of Merz and Son, of Munich, was purchased, which was mounted and ready for use in June, 1861.

 

Mr. Scott remained in office for four years, and resigned his position on 30th September, 1862.

 

The astronomical work done at the Sydney Observatory in Mr. Scott's time was fully published by him in the four official volumes issued for the years 1859, 1860, 1861, and 1862. These contain the results of upward of 6,600 meridian observations in both co-ordinates, about 100 transits of the moon and moon culminating stars, a large number of observations of zenith stars for latitude, and some observation of comets.

 

The 7¼-inch Merz equatorial was at his disposal only fifteen months, during which some attention was given to double stars.

 

Mr. Scott published some of his other astronomical work in the Monthly Notices of the R.A.S., Vols. 19, 20, 21, and 22, as follows :- Observations of the Solar Eclipse of the Sun, 11th January, 1861; Comet III., 1860; Comet II., 1861; Encke's II., 1862; Transit of Mercury N 4, 1861.

 

The instrumental faults never permitted Mr. Scott to assign to his meridian observations a degree of accuracy equal to that of the best observatories.

 

"It must therefore be borne in mind" he tells us "that determination of right ascension with the Sydney transit circle are liable to errors varying from 3.3 to -4.2 seconds of arc, or 0.22 to -0.28 seconds of time for a equatorial star." "An examination of the North Polar distances leads to a very similar result" (9),

 

From September, 1862 to January, 1864, the Observatory was in charge of Mr. Hem-y Russell, B.A., who had joined the Observatory as Mr. Scott's assistant in 1859.

 

Mr. Russell confined his astronomical duties to the time service and to the observation of transits of the moon and moon culminating stars. He also made a series of micrometric measurements for the comparison of Mars with neighbouring stars, at the opposition of 1862. This series, however, was not published (6).

 

Mr. George Robert Smalley, B.A., succeeded Mr. Scott as the second Director of the Sydney Observatory, in 1864, being selected by the Astronomer Royal - Sir George Airy - at the request of the colonial authorities.

 

It seems that the imperfection of the meridian instruments as reported by Mr. Scott discouraged Mr. Smalley from undertaking any serious and systematic work with them, and he resolved to employ them only for the ordinary requirements of the time service. He devoted the rest of his time to magnetic and meteorological investigations and to the initiation of a trigonometrical survey of the colony, which was then urgently required. Eventually the Government intrusted him with that work, and operations were commenced in due course for the measurement of a base line at the south end of Lake George.

 

Difficulties and delays were encountered in these operations and the worry "told seriously on Mr. Smalley's health, and during the latter part of 1869 and all 1870 till his death in July of that year, he was not able to do much of the work which he had determined to carry out" (6).

 

The only astronomical work done during these years, in addition to the observation of clock stars, were some observations of Comet I., 1864, made by Mr. Smalley with the Merz 7¼-inch equatorial, and published in the Monthly Notices of the R.A.S., Vol. 25, p. 171 ; and observations of Comet I., 1865, and of Encke's Comet at its return in 1865, which were published in Monthly Notices, Vol. 26, p. 63-

 

Mr. Russell succeeded Smalley as third Director of the Sydney Observatory and Government Astronomer of the colony of New South Wales.

 

"Having had a share in all the work done with the meridian circle, and knowing its imperfections, he determined to confine the observations with it to those required for time and longitude, and at once urged the necessity for a new meridian instrument" (6).

 

The approaching transit of Venus gave him the opportunity of obtaining the sympathy of the Government for the acquisition of more instruments.

 

The astronomical operations which figure more prominently in the history of the Sydney Observatory during the first seven years of Russell's regime are the preparations made for observing the total eclipse of the sun in December, 1871, in the extreme north of Australia, and the transit of Venus in 1874, of which a brief account will be given in another part of this article.

 

To the ordinary routine of observations of clock stars were added observations of the transit of the moon and moon culminating stars for longitude, and the observations of Herschel's Cape Catalogue of Double Stars.

 

A remarkable feature of this period is the increase of instrumental power which Russell, by continuous effort and determination, succeeded in securing for his observatory.

 

In 1872, with the assistance of the Royal Society of New South Wales, he obtained from the Government a sum of £1,000 for instruments, the greater part of which he used in procuring an achromatic object glass, 11.4 inches aperture, and 12½ feet focal length, by Schroeder, of Hamburg, for which he designed and had constructed in the colony under his supervision an equatorial mounting provided with all the requisites of a modern instrument. This instrument was installed in 1874.

 

In the same year the necessity having arisen for the determination of star positions with the greatest possible accuracy to serve the purposes of the trigonometrical survey of the colony of New South Wales then in course a sum of £1,000 was granted by the Government for the purchase of a high-class transit circle for the observatory; Mr. Russell ordered the instrument from the firm of Troughton and Simms, and procured also a large eighteen-prism spectroscope, by Hilger, and other apparatus.

 

The new transit circle has an object glass of 6 inches clear aperture and 85 inches focal length. It has two circles graduated to every 5' read by four microscopes; regular observations with it were commenced in February, 1877.

 

The instrument was employed for observations of stars required in the operations of the trigonometrical survey, and of other stars near the zenith, of which it was intended to make a special catalogue.

 

"In fact, since 1870, the observatory has been entirely refurnished with instruments of the most modern and perfect forms, and, although they are not equal in size to some of the giant telescopes which have been recently erected in Europe at enormous cost, they are quite equal in quality to those in the best European observatories, as is proved by the observations now made with them." Thus Russell wrote in 1882 (6).

 

An important series of meridian observations of Mars at its opposition in 1877 and comparison stars had been obtained by Russell with the new transit circle "for the purpose of determining the solar parallax. A long series of observations was made which, combined with observations made at Washington, gave 8.885 inches as the value of the solar parallax " (6).

 

The results of the work done with the transit circle up to the end of the year 1881 are published in two volumes, "Sydney Observatory - Astronomical results for the years 1877-78 and 1879-1881." These results were used by A. Stichtenoth to form a catalogue of 1,543 stars for the epoch 1880, published in Veroffentlichungen des Koniglichen Astronomischen Rechen-Instituts zu Berlin, No. 20.

 

The results of observations on double stars are published in a separate volume, Sydney Observatory - Double Star Results, 1871-1881.

 

In the first volume of astronomical results is shown a summary of the observations of transits of the moon and moon culminating stars made by Russell in the years 1863, 1871, 1872, 1873, and 1874, from which is derived the value of the longitude of Sydney (according to Russell), 10h. 4m. 50.81s., which was adopted till 1883.

 

During the eight years after 1881, the same routine of meridian observations and observations of double stars were continued.

 

The double-star work of the years 1882-1889 was published in Memoirs R.A.S., Vol. 50.

 

In 1887 Mr. Russell went to Europe to attend the Astrophotographic Congress at Paris, and on behalf of his Government and the Government of the colony of Victoria, pledged the Sydney and Melbourne Observatories to undertake a share in the astrophotographic programme which was decided upon by that Congress.

 

The part of the sky allotted to Sydney ranged from 57° to 61° of south declination, and that of the Melbourne Observatory from declination -65° to the South Pole.

 

Russell obtained his photographic object glass from Steinheil, of Munich, and had the mounting, with all requisite accessories, made in the colony on his own design, and under his personal supervision. He had a circular wooden observatory detached from the main building, built for the special purpose of housing this astrophotographic telescope.

 

The mounting of the astrograph was ready in 1890, but the object glass did not arrive till later. Russell, in the meantime, mounted a Dallmeyer portrait lens 32 inches focal length and 6 inches aperture, and, finding this star camera to the tube of the astrograph, employed it in taking a series of highly successful photographs of the Milky Way. These photographs, seventeen in number, accompanied by a description of each, form an album which was published in 1890.

 

The installation of the new object-glass was completed in 1891, and the work reached the end of the preliminary experimental stage in 1892, from which time it proceeded regularly in succeeding years till 1898.

 

In 1889 powerful street lamps and electric lights were placed in the vicinity of the Observatory, the effect of which was to interfere so seriously with the work of the astrograph that it became necessary to remove the instrument to some better locality.

 

Accordingly, the Government, having granted a piece of land for this purpose at Pennant Hill, some 11½ miles to the north-west of Sydney, and 615 feet above sea-level, a suitable building was erected, and the instrument installed there in 1899, where the astrophotographic work has since been carried out by Mr. Short, as a branch of the Sydney Observatory.

 

For the last 22 years the determination of the places of reference stars to be employed for the reduction of the plates of the Photographic Catalogue, and actual photographing of the regions comprised in the Sydney zones, constituted the greater part, if not the whole, of the astronomical programme of the Sydney Observatory, the results of which have not yet appeared.

 

During this long period observations of double stars were continued, the results of which have been published in various lists in the A.N., Nos. 31.54, 3240, 3303, 3369, 3423.

 

Many other observations of an occasional character were made, and other astronomical duties performed, which come within the scope of a national observatory, but it would be impracticable to give here a detailed account of them.

 

Russell, who died in 1907, may be regarded as one of the principal factors in the advancement of Australian astronomy during the last half century. In estimating the value of his work, it must be remembered that by far the greater part of his energies were expended on the development of Australian meteorology.

 

He was the inventor of no less than 23 instruments, and the contributor of some 130 papers to various scientific societies. He was made F.R.A.S. in 1871, F.R.S. in 1886, C.M.G. in 1891, also, in the same year, Vice-Chancellor of the Sydney University, where he graduated in 1858, and President of the R. S. of New South Wales for some years.

 

After Russell's death, Mr. Alfred Henry Lenehan was appointed Government Astronomer. Under him the astronomical work of the Observatory was a continuation of the routine programme of previous years, which he was bound to accept and to advance as speedily as he could, under the administrative difficulties of the time, till completion might be reached.

 

He died on 2nd May, 1908; and till August, 1912, Mr. W. E. Raymond remained in temporary charge of the institution.

 

In August, 1912, Mr. W. E. Cooke, M.A., formerly Director of the Perth Observatory, was appointed Government Astronomer of New South Wales, and Professor of Astronomy in the Sydney University.

 

In his report to the R.A.S., M.N., February, 1913, No. 4, Vol. LXXIII., we read  -  

 

"Owing to the rapid growth of Sydney, the present site of the Observatory has become unfit, and the instruments are not suited for the exacting requirements of modern astronomy. It has therefore been determined to move the entire institution to a new site, and to provide some new instruments and remount others. In particular, a new meridian instrument of modern design, suitable for fundamental work of the highest precision, will be provided in accordance with the recommendation of the Paris Astrographic Congress of April, 1909.

 

"Meanwhile the routine work has been almost stopped for the present, and preparations for the reorganization have been commenced."

 

 

The Williamstown Observatory

 

E. L. J. Ellery was appointed, in 1853, by the Government of the Colony of Victoria to establish a small observatory at Williamstown, chiefly for the purpose of determining time and supplying a daily time signal for the service of ship masters.

 

On taking up his position, Ellery found the following preliminary arrangements already made :-

 

A time ball apparatus already installed on a tower at Point Gellibrand, with the requisite apparatus and machinery for hoisting and dropping the ball.

 

Some astronomical instruments, including a transit instrument on order in England.

 

A site for the Observatory selected.

 

A sum of £2,800 voted by Parliament for the erection of a suitable building.

 

Under these conditions he set to work in a wooden hut, using a sextant and a chronometer, and the first time signal was issued in August, 1853.

 

Such was the beginning of the Williamstown Observatory.

 

The geographical position of the place had been determined some years previously by Captain Stokes, of H.M.S. Beagle, his values being - Latitude 37° 52' 52" S. Longitude 9h. 39m. 42s. E. In 1854, the instruments on order in England arrived. They were a 25-inch transit instrument and a high-class astronomical clock, by Frodsham. A more ambitious transit instrument, which had been ordered from the firm of Troughton and Simms, arrived in 1855. This was an excellent instrument, with an object glass of 3½ inches clear aperture and 45 inches focal length.

 

In 1858, the geodetic survey of the colony was decided upon, and placed in charge of the astronomer. The proposed scheme was to divide the country for purposes of land settlement by meridians and parallels, the primary lines being first located at distances of 1°.

 

The Observatory having by this time acquired national importance, on account of its public duties in connexion with the geodetic survey and time service, the Legislature passed a resolution on 8th December, 1859, according to which a Board of Visitors to the Observatory was appointed by the Governor in Council on 30th January, 1860, the Governor (Sir Henry Barkly) becoming himself chairman of the first Board.

 

A new circle arrived in August, 1861. It was constructed by Troughton and Simms. Its object glass has a clear aperture of 5 inches and a focal length of 72 inches. The circle is of gun metal, 4 feet in diameter, divided to every 5 minutes, and read by four microscopes attached to one of the two stone piers which support the instrument. Observations with this instrument commenced in October, 1861.

 

A new clock, also by Frodsham, had arrived a year before, and still more instruments were acquired in this and in the following year. These were a chronographic apparatus, by Siemens and Halske, of Berlin; an Airy zenith sector; and an achromatic telescope, equatorially mounted. This latter instrument, by Troughton and Simms, has an object glass of 4½ inches clear aperture and a focal length of 5 feet; with it a valuable series of observations of Mars at its opposition of 1862 was obtained for determining the parallax of the sun in connexion with other observatories.

 

In 1853 the site occupied by the Williamstown Observatory seemed quite suitable for an observatory, but the rapid growth of the community, the construction of a railway terminus and large railway workshops near it, had in 1862 rendered its position unfavorable, in consequence of which it was decided to remove it to Melbourne.

 

Since 1857, there had been in existence a meteorological and magnetical observatory, which was established and conducted by Professor George Neumayer. This observatory was situated at Flagstaff Hill, at the west end of the city of Melbourne. In 1863, Professor Neumayer, having decided to leave Australia, it was arranged that his observatory should be amalgamated with the new Astronomical Observatory.

 

The building for the new Observatory was commenced in 1861 and completed in 1863.

 

In June of that year the Williamstown Observatory was dismantled, and "the whole of the instruments and appliances removed to the new building now known as the Melbourne Observatory" (11).

 

The results of the work done at the Williamstown Observatory are published in the volume entitled - Melbourne Observatory. Astronomical Results. 1861-62-63.

 

This volume contains the Williamstown catalogue of 546 Stars for the epoch 1860, which at the time it appeared received warm appreciation from European and American astronomers. Also a series of right ascensions and north polar distances of the moon, extending from January, 1861, to 7th October, 1862, upon which rested the longitude of the Williamstown Observatory; and finally, the series of observations of Mars and comparison stars during the opposition of the planet of 1862.

 

 

The Melbourne Observatory.

 

This Observatory is situated at a distance of 4 miles north-east from the site of the old Williamstown Observatory, and about 1 mile south- east from the centre of the city of Melbourne, within an enclosure of 4½ acres of land permanently reserved for observatory purposes in the Domain Park.

 

In addition to the main building, which provided ample accommodation for the astronomical instruments of the Williamstown Observatory, special structures were erected for the magnetic and meteorological instruments which were taken over from Professor Neumayer's Flagstaff Hill Observatory.

 

The Melbourne Observatory was ready to commence work at the end of June. 1863, its astronomical equipment consisting of the instruments removed from the former Observatory at Williamstown.

 

For nearly three years the work consisted almost entirely of meridian observations of the fixed stars which were employed in the operations of the geodetic surveys then in course in Australia and South America. A catalogue of these stars was prepared each year and printed in due course.

 

In 1862 the Royal Astronomical Society initiated a movement for carrying out by British effort a southern durchmusterung on the same basis and the same scale as that which Argelander was conducting for the northern hemisphere. The idea was to obtain the co-operation of the three southern observatories - Madras, Cape of Good Hope, and Melbourne.

 

The Melbourne Observatory offered to join in the work, and was eventually allotted the zone from 60 degrees to 80 degrees of south declination.

 

The undertaking involved the determination of the positions of all the stars comprised in this southern belt down to the tenth order of magnitude.

 

This work was commenced on 11th April, 1866, and continued for about six years, when it had perforce to be discontinued. Its results comprise the mean places for the epoch 1875 of 48,672 stars down to the 9th, and in many instances the 10th order of magnitude, in the zone from 65 degrees to 69 degrees of south declination. These places are roughly arranged in the MS. in order of right ascension, the right ascensions being given to the nearest tenth of a second of time, and the north polar distances to the nearest second of arc, showing that the work aimed at a somewhat higher accuracy than that of other works of this class, such as Argelander zones or

the C.P.D.

 

With very little labour the work can be arranged and prepared for printing if means be provided for the purpose.

 

In the year 1850 a memorial was presented to Lord Russell, the object of which was a request to Her Majesty's Government to establish "a powerful reflecting telescope (not less than 3-feet aperture in some fitting part of Her Majesty's Dominions, and for the appointment of an observer charged with the duty of employing it in a review of the nebulae of the southern hemisphere."

 

The opportunity of enhancing the importance of the Observatory by the acquisition of a great reflecting telescope was quickly recognised by the Board of Visitors, and His Excellency the Governor (Sir Henry Barkly) was requested to obtain "an expression of opinion from scientific men in England as to the importance of the results to be expected from it, the most suitable construction of telescope for the purpose, both as to the optical part and the mounting, its probable cost, and the time requisite for

its completion."

 

"An application was made through the Secretary of State for the Colonies to the Royal Society of London for their opinion, and the President and Council of that body, after a very full consideration and a long correspondence with the most eminent practical astronomers of the day, recommended-

(a) That the telescope be a reflector, with an aperture of not less than 4 feet; (b) That the large mirror be of speculum metal; (c) That the tube be constructed of open work and of metal" (12).

 

The instrument was completed in 1868 and was sent to Australia, reaching Melbourne in November of that year; it was ready for work by the end of June, 1869, and the observations commenced in August of the same year.

 

Grubb's 4-feet reflector has, since its installation, been styled "The Great Melbourne Telescope." An admirable description of it by the late Dr. T. Romney Robinson, D.D., F.R.S., appears in the Philosophical Transactions of the Royal Society of London, 1869, page 127 (13).

 

The telescope itself is of the Cassegrainian type, and is mounted equatorially in a somewhat similar form to the Sisson; "its declination axis being placed between the upper and lower pivots of the polar axis, which run in large bearings, supported by two distinct massive stone pillars rising from a solid bed of masonry. The R.A. circle clamps and slow motion apparatus are between the declination axis and the lower pivot. The declination circle is fixed to the bearings of the declination axis on the side of the polar axis, opposite to that of the telescope" (13).

 

The dimensions of the optical parts are as follow :- Aperture of primary speculum, 48 inches; focal length of primary speculum, 360 inches; aperture of secondary speculum, 8 inches; focal length of secondary speculum, 74.7 inches; equivalent focal length, 1.994 inches.

 

There are two large 4-feet mirrors, each mounted in its cell ready for attachment to the telescope, floating on a complicated support of 48 cups and balls connected to the ends of arms which form a series of triangular levers, and upon hanging rings around its circumference. These mirrors have a central circular opening of 8 inches in diameter to admit the passage of the cone of rays from the convex secondary mirror to the ocular. The mirrors, both primary and secondary, are of speculum metal.

 

The tube of the telescope consists of three portions. The lower, or "eye end" portion consists of the cell carrying the large speculum ; the central portion is a cylinder of boiler plate, about 93 inches long, to which is attached the declination axis by means of a massive cast-iron cradle and strong iron bands embracing the cylinder. The speculum cell fits to the end of this cylinder on turned surfaces, and is held to it by three strong screw-bolts. The upper portion of the telescope tube is made of open steel lattice-work, about 20½ feet long, fixed by turned flanges to the boiler plate cylinder by bolts and nuts.

 

The secondary mirror, in its cell, is mounted in the centre of the lattice tube, about 300 inches from the surface of the primary speculum and 39 inches within the object end of the tube, and means are provided to enable the observer while at the eye end to alter this distance for focussing.

 

The polar axis is 123 inches long, and its two pivots are 12 inches in diameter. The declination axis has a diameter of 22 inches at the bearing near to the telescope, and 9| inches at the counterpoise end. The circles are divided on silver bands, and have a diameter of 30 inches.

 

The driving clock is governed by a double conical pendulum of the well-known "Grubb" form. The direct driving weight is 260 lbs., and the total weight of the moving parts is approximately 18,000 lbs.

 

The instrument is provided with an achromatic telescope finder, 4 inches aperture, seven negative or Huygenian eye pieces ranging in power from 234 to 1,000, a parallel wire micrometer, a spectroscope, and a camera for photographing telescopic images at the focus of the primary mirror, the secondary mirror being removed when the camera is used.

 

In 1910, a Voigtlander portrait lens of 6 inches aperture and 40 inches focal length, for which a metallic mounting was made at the Observatory, was attached to this telescope.

 

The great Melbourne telescope was for many years after 1869 employed in the revision of the nebulae and clusters which were observed by Sir John Herschel at the Cape of Good Hope in the years 1834-38, and the results obtained are as satisfactory as the committee of the Royal Society of London, on whose recommendation, supervision, and approval the 4-feet Cassegrain was constructed, could have expected.

 

Most of Sir John Herschel's southern nebulae have been examined, and many hundreds of drawings of these objects, with notes and micrometric measurements, exist at present in the observer's note books and registers; but there has been no opportunity since 1891 of arranging this material for publication.

 

In 1871, an expedition to the extreme north of Australia was organized for the observation of the total eclipse of the sun in December of that year, in which the Melbourne Observatory took part. This expedition is referred to in another division of this paper.

 

In 1874, the occasion of the transit of Venus, which occurred in that year, gave Ellery the opportunity to add to his observatory equipment a photoheliograph, by Dallmeyer, with object glass 4 inches aperture and 60 inches focal length ; an achromatic telescope, 8 inches aperture, 110 inches focal length, by Troughton and Simms, mounted equatorially and provided with all requisites for micrometric measurements and work of the highest precision; also another equatorial telescope, 4½ inches aperture and 60 inches focal length, by Cooke and Sons, of York.

 

The preparations for observing the transit of Venus included the dismantling of the east transit telescope of 6¼-inch aperture, with which the Melbourne zones had been observed till 1872. For this telescope an equatorial mounting was constructed at the Observatory, and the instrument has since been used for expeditions as a portable equatorial.

 

Two new barrel chronographs were also constructed at the Observatory.

 

After the transit of Venus, it became a part of the daily routine to take a photograph of the sun in the forenoon, which was done on all available opportunities for more than 20 years.

 

In the time which elapsed between the two transits of Venus of 1871 and 1882, the routine astronomical work of the Observatory did not suffer any marked changes or interruptions.

 

Stellar photography was tried with the great telescope, but unsuccessfully. It was not found practicable to guide the telescope steadily enough during exposure. Photographs of the moon with the great telescope, which only required an exposure varying from 1 second to 3 seconds (with wet plates) were, however, successful, and they were even considered at the time amongst the best that had ever been obtained.

 

The photographs of the moon obtained at the focus of the primary mirror were 3½- inches in diameter.

 

The pictures of the sun obtained with the photoheliograph were 4 inches in diameter. One thousand seven hundred and twelve of these pictures on glass were sent to the Greenwich Observatory and the Solar Physics Committee in England, for measurement and tabulation (14).

 

The preparations for the transit of Venus of 1882 and the observations of that astronomical event in this State will be dealt with under another heading.

 

The determination of the difference of longitude between Port Darwin and Singapore, and between Port Darwin and the Australian observatories, which were undertaken in 1883, will also be dealt with separately.

 

In the year 1883, a "Central Bureau for the Telegraphic Exchange of Astronomical Information" was established at Kiel. It was arranged among the principal Observatories that all urgent astronomical intelligence and discoveries should be communicated to the Central Bureau at Kiel, which would at once transmit the news to various secondary centres to be established for the purpose in every part of the world, and thence to all astronomers concerned. The Melbourne Observatory was requested to act as the secondary centre for Australia, and it has since been its duty to communicate to the other Observatories of Australasia any astronomical news cabled from Kiel, and to receive announcements of astronomical discoveries or other important astronomical intelligence from any part of Australasia for telegraphic transmission to the Central Bureau at Kiel.

 

Until August, 1884, all meridian observations were made with the 5-inch transit circle, and the results were published in seven volumes, the first of which contained the work done at Williamstown as already mentioned. The six subsequent volumes contain all the separate results from each observation and the annual Catalogues of concluded Right Ascensions and North Polar distances for each year.

 

The first general Catalogue for the Epoch 1860, containing the positions of 546 stars, is that printed in Volume I. A second general Catalogue for the Epoch 1870 was prepared and printed in 1874. This contains the positions of 1,227 stars. A third general Catalogue for the Epoch 1880, containing 1,211 star places was published in 1889.

 

In May, 1884, a larger transit circle arrived from England, constructed by Troughton and Simms, and is of somewhat similar dimensions and design to those constructed by the same firm for the Observatories of Cambridge, England, and Harvard College, United States of America. Its object glass has an aperture of 8 inches and a focal length of 108 inches. Its two circles are 3 feet in diameter, being divided to every 5 feet, and each read by four microscopes.

 

The two circles are at opposite ends of the axis, which is 52 inches in length, and has pivots 4½ inches in diameter. The pivot bearings rest on two short iron pillars, which stand on massive stone piers.

 

The reading microscopes are carried on gun metal circles attached to the short iron pillars.

 

From August, 1884, to the present time all meridian observations have been made almost exclusively with this instrument.

 

During the period 1884-1891, the astronomical work of the Observatory was similar in character to that of preceding years.

 

The meridian observations made with, the new transit circle comprised the usual clock stars, a special list of circumpolar stars, which were assiduously observed year after year, stars employed for comparison with comets, stars selected by Dr. Auwers for the formation of a "fundamental Catalogue of Southern Stars," and others in connexion with the reduction of the Melbourne zones and transit of Venus observations ; also a list of stars required by the Bureau des Longitudes for insertion in the Connaissance des Temps, and another list of stars used by Dr. Gill in some of his heliometer work.

 

The observations of the southern nebulae with the great telescope, and observations made with the smaller equatorials, comprising extended series of observations of all the comets which were visible from Melbourne, and a preliminary spectroscopic survey of the southern stars brighter than the 5th magnitude, form the bulk of the extrameridional work of this period. It has been stated in a previous page that the share allotted to the Melbourne Observatory in the Astrophotographic Programme, which was agreed upon at the Paris Congress of 1887, covered the south polar area of the heavens limited by the 65th parallel of south declination.

 

Some description of the instrument required for this work has been already given. The one for this Observatory arrived in Melbourne at the end of December, 1890.

 

It was constructed by Sir Howard Grubb, of Dublin, and is similar in all respects to those constructed by the same makers for the same purpose for the Observatories of Greenwich and Cape of Good Hope.

 

It consists of a double telescope, mounted equatorially on a massive cast-iron stand in what is known as the German model.

 

The two telescopes are roughly of the same length, but of different aperture. The larger, which is employed for photographing, has an object glass of 13 inches aperture and 135½ inches focal length, and is corrected for spherical and chromatic aberration for rays close to Fraunhofer's spectral line G.

 

The smaller telescope is used for guiding the instrument by visual observation during exposure. Its object glass is 10.1 inches aperture and 130 inches focal length. The driving clock is within the stand, and is controlled electrically by a seconds pendulum, the driving being corrected automatically by a system of differential wheels devised by the maker.

 

In September, 1892, a financial depression necessitated a policy of retrenchment, and for some years the work of the Observatory was hampered by the inability of the Government to adequately support it. The year before the astronomical work of the Observatory had to be reduced to a minimum Ellery wrote in his report of 2nd September, 1891 -

 

"The work of the year is clearly before us. The Melbourne portion of the photographic charting of the heavens, with its collateral work, will use up nearly all our available working power. The meridian work will largely monopolize the Meridian Observing and Computing Staff, while obtaining photographs, developing, and otherwise dealing with the plates will take up the whole attention of two or three members of the staff both night and day. I propose, therefore, to confine the astronomical work, for the present at least, to the routine meridian observations, coupled with the observations for guide stars, and to the special photographic work with the astrograph, undertaking only such occasional extra meridian work as may from time to time demand attention."

 

In 1895 the astronomical strength of the Observatory was further very greatly reduced by the retirement of Ellery in June of that year. During his tenure of office he had raised the institution from very humble beginnings to the rank of a "First Order " Observatory.

 

We were left, a band of four, to carry out the meridian and the astrophotographic work. This band remained the same till 31st December, 1907, after which date a fundamental change took place and a new epoch commenced for the Melbourne Observatory.

 

The Annual Catalogues of Stars, observed with the 8-inch transit circle from August, 1884, to 31st December, 1912, were regularly constructed and completely prepared for publication, but have not yet been printed. Those of the years 1884-1893 were used for the compilation of the Third Melbourne General Catalogue for the epoch 1890; the work, which contains 3,100 stars, will very shortly be ready for issue.

 

The Annual Catalogues from 1894 to 1912 contain, in addition to the standard clock and azimuth stars and some 134 zodiacal stars which were observed at the request of the Cape Observatory, all the stars which are employed as standard reference stars for the reduction of the Melbourne plates of the photographic catalogue.

 

With these annual catalogues, up to the year 1910, a special catalogue of 6,680 standard reference stars for the epoch 1900, all observed at least three times, has been prepared.

 

The total number of stars of this class required for the full reduction of the Melbourne plates is about 9,160, and 2,480 stars are therefore still required to complete the Melbourne share of the astrophotographic catalogue.

 

Of this number, 636 stars have been observed three times, 379 twice, and 496 once, while 969 stars still remain to be observed three times. It is estimated that these observations will be completed by the end of 1914, after which an additional catalogue for the epoch 1910 will be prepared.

 

The series of Melbourne catalogue plates has been completed. A series of chart plates, with single exposures of one hour, covering singly the whole area around the South Pole down to the 65th parallel of south declination, has also been completed. In this series the centres of the plates were set at the even degrees of declination.

 

Another series of chart plates, with three exposures of thirty minutes each, the three images forming a small equilateral triangle with sides of 8 inches has been advanced to the extent of 431 single regions out of 584 regions comprised in the full Melbourne area. The centres of these triple exposure plates were set at the odd degrees of declination from the 65th parallel to the Pole.

 

For the measurement of the catalogue plates, an arrangement was made in 1898, by which both the Sydney and Melbourne plates were to be measured at the Melbourne Observatory, at the joint expense of the Governments of New South Wales and Victoria; a Measuring Bureau was created and the necessary staff trained at the Melbourne Observatory for the purpose.

 

The regular measurements commenced in 1900, but a satisfactory rate of progress was not reached till 1901.

 

The computation of plate constants for the Melbourne regions and the tabulation of rectilinear co-ordinates for publication are now in course of preparation, and a first volume , containing the zones -65 and -66, is ready for press.

 

The total number of stars in this catalogue is over 300,000, and will occupy eight quarto volumes of about 300 pages each.

 

On the 1st December, 1908, the Government of the Commonwealth of Australia took over, and assumed control of, the meteorological services of the various States uniting them under a single Commonwealth Department of Meteorology, and thus the Australian Observatories were freed from a burden which had for a quarter of a century retarded the advancement of Australian Astronomy.

 

Since the middle of the year 1908 to the present date, the principal parts of the working routine programme of the Melbourne Observatory have still remained the same as those of previous years, namely, meridian observations and astrophotographic operations.

 

The meridian observations have been made generally upon the reference Stars of the Photographic Catalogue, Southern Stars in Auwers' Fundamental Catalogue, Stars selected for investigation of refraction, personal, and magnitude equation, Clock and Azimuth Stars.

 

The object of the astrophotographic operations has been to advance a second series of catalogue plates and the series of chart plates with triple exposure.

 

The progress made in the reduction of these observations and in the preparation of results for publication has already been stated.

 

The record of other classes of astronomical observations and investigations undertaken during the period is as follows :- A series of 100 photographs and measurements of position of Comet C (1908) Moorhouse; thirteen photographs and some 300 comparisons with stars of Halley's Comet; observations of Comet Borelly (1911e), Gale (1912a), Tuttle (1912;), Faye-Cerully (1910e), Kiess (19116); observations of Variable Stars of long period, south of declination -30; investigation of the Reseaux Melbourne No. 6 and Melbourne N 23; investigation of the division errors of the 8-inch transit circle.

 

 

The Adelaide Observatory

 

In 1855, the late Sir Charles (then Mr.) Todd was appointed in England Superintendent of Telegraphs and Astronomical Observer for the Colony of South Australia.

 

It does not appear that any astronomical work had been done in South Australia, except for geographical purposes, before Todd's arrival nor for twelve years after it.

 

In 1867 the transit instrument of 32--inches aperture and 15 inches focal length, which had been originally employed at the Williamstown Observatory, was transferred to Adelaide on loan from the Victorian Government, and for the purpose of making meridian observations in connexion with longitude operations required for establishing the position of the eastern boundary of the Colony. It was not until 1874, however, that a suitable Observatory and some astronomical equipment were provided by the South Australian Government for its astronomer. The present Adelaide Observatory was erected in that year.

 

The astronomical instruments comprised, at first, an astronomical clock by Frodsham, the ½-inches transit instrument borrowed from the Victorian Government, and an equatorially-mounted telescope by Cooke and Son, 8-inches aperture, and nearly 10 feet focal length, provided with all the requisite accessories of a first-class instrument. The last-named instrument was employed for the observations of the phenomena of Jupiter's satellites, for the study of surface detail of this planet, and for comets.

 

Meridian observations were made only for determining local time, a time ball placed on a tower at the Semaphore, 9 miles distant, being dropped automatically from the Observatory at 1 p.m. daily. The first time signal was given on 2nd August, 1875.

 

In 1880 a transit circle by Troughton and Simms, with object glass 6-inch clear aperture, and 85 inches focal length, was obtained, being similar in design to the transit circle of the Sydney Observatory, except that the two divided circles at the opposite ends of the axis are larger, their diameter being 30 inches.

 

"The first work undertaken was the observation of stars in Weisse's Catalogue, between 0° and 4° south declination, the intention being to include all stars down to the 10th Magnitude, between 0° and 15° south, a work which would have occupied several years. Exclusive of clock and azimuth stars, we had 4,072 observations in R.A., and 4,099 in N.P.D. of stars in the belt (0-4) referred to, by July, 1892" (15).

 

This work was then suspended, Todd's attention having been called to the discordance in the observations of N.P.D. in the South and North Hemisphere.

 

Observations were made, for latitude, of 297 stars near the zenith of Adelaide, 118 stars from 1st to 4th magnitude whose zenith distance ranged up to 30 degrees north and south, observed either during day or night ; and 127 circumpolar stars so selected that five or six were observed above and as many below the pole, the same stars being observed in the reverse order after an interval of six months.

 

Later the zenith distances of 300 stars at all altitudes were observed in the years 1893 and 1894.

 

These were selected from the Greenwich ten-year catalogue 1880.

 

180 circumpolar stars were observed for latitude in 1894 and 1895, in addition to a small list of 23 stars, of which several bisections were made at the same transit and the Nadir taken before and after every observation, and another list of 53 stars arranged in three groups - one of stars near the zenith, one of stars about 40° south, and one of stars about 40° north of the zenith. This latter list was observed at the same time at the Observatories of Melbourne and Sydney by arrangement.

 

For some years after 1897 the astronomical work of the Observatory consisted mainly of meridian observations for time, and occasional observations of comets and of Jupiter's satellites.

 

The publications of this Observatory have been mainly meteorological, consisting of annual volumes, dating from 1876 to 1907 inclusive. Various astronomical memoranda, such as observations of Jupiter's surface markings, satellite phenomena, eclipses of the sun and moon, etc., are included as appendices to these volumes, and some miscellaneous papers have been printed in the Monthly Notices of the R.AS. and in Proceedings of the Australasian Association for the Advancement of Science.

 

The unpublished work comprises all the meridian observations made with the transit circle since the beginning in 1889, and the physical observations and drawings of Jupiter, of which a large series was obtained in the years 1884 to 1894, together with a set of over 200 drawings, made during the same period, and arranged for publication on an orthographic projection.

 

Sir Charles Todd retired in December, 1906, and was succeeded by R. F. Griffith, who was appointed Acting Government Meteorologist on 1st January, 1907. He resigned his position at the end of that year to join the newly-created Department of Meteorology under the Commonwealth Government, and Mr. G. F. Dodwell, B.A., was then placed in charge of the Observatory. On 1st June, 1909, Mr. Dodwell was appointed Government Astronomer of South Australia.

 

The present programme of astronomical work at the Adelaide Observatory is as follows : (a) Time determinations; (b) Observations of reference stars of Sydney Astrographic Zones; (c) Field latitude and longitude determination; (d) (Seismology) variables, double stars, and miscellaneous observations with the 8-inch Cooke equatorial.

 

The observations of variables and double stars have now been commenced by certain members of the local Astronomical Society, the equatorial telescope of the Observatory being used for this purpose.

 

Negotiations are in progress concerning a proposal to undertake latitude variation work in conjunction with the La Plata Observatory.

 

The instruments of this Observatory at the present day are those which formed the equipment of the Observatory since 1889, namely, the 6-inch transit circle and the 8-inch equatorial, the additions being only a portable universal instrument, chronometers and other minor apparatus.

 

The Adelaide Observatory is supported by the South Australian Government and administered as a branch of the State Department of Education.

 

 

The Perth Observatory, Western Australia

 

This Observatory started its career in 1896 as an astronomical and meteorological institution administered as a branch of the Colonial Secretary's Department, Mr. W. E. Cooke, M.A., being appointed Director.

 

It is situated upon Mt. Eliza - a sand hill some 200 feet above sea level, rising from the western boundary of and overlooking the city of Perth - and commands an almost uninterrupted view of the horizon on all sides (16).

 

Its geographical position is - Latitude, 31° 57' 10.27" South; Longitude, 7h. 43m. 21.74 east.

 

The climate of the locality is considered very favorable for astronomical work, except in February and March, and in the winter months, when observing is more frequently interfered with by smoke, cloud or rain.

 

In the first few years of its existence the Observatory was gradually provided with the following instruments, namely:- An 8-inch reflecting telescope intended for use with a coelostat; a transit circle, by Troughton and Simms, with object glass 6-inch aperture and 71 inches focal length, with two divided circles 30 inches in diameter; a twin astrographic instrument, by Sir Howard Grubb, of the standard pattern and size employed by the observatories co-operating in the international astrophotograhic programme; two machines for the measurement of astrophotographic plates, similar to those employed at Greenwich and Oxford; a 12-inch reflecting telescope; a barrel chronograph, with Grubb's "mouse" control; an astronomical clock, by Victor Kullberg, regulated to sidereal time; a mean-time clock; and two chronometers, a 5-inch theodolite, and minor observatory apparatus, accessories, and appliances.

 

For some years the astronomical work of the Perth Observatory was confined mostly to meridian observations for local time, for the investigation of instrumental errors of the transit circle and for the accurate determination of its geographical position.

 

In the year 1900 the Government of Western Australia was invited to carry out the astrophotographic programme originally assigned by the Paris Congress of 1887 to the Observatory of Rio Janerio, which, however, had not been able to start the work. The invitation was accepted, and the photographing of the zones comprised between the parallels of 31 degrees and 41 degrees of south declination was undertaken by the Perth Observatory. This circumstance established the nature of the work upon which the transit circle and the astrograph were to be utilized from that time to the

present.

 

The transit circle was to be devoted to the observation of reference stars within the Perth photographic zones, and the astrograph to obtain the requisite photographs of these zones.

 

This work commenced in 1901. At first, owing to the meteorological duties of the Observatory, progress was slow, but from the end of 1907, when meteorology became a Federal concern, the work advanced vigorously, as shown by the extensive publication of its results.

 

The character of the task undertaken by observatories participating in the international astrophotographic programme has been previously described here in connexion with the Sydney Observatory, and it will be sufficient to remark that the Perth zones, ranging from -31° to -41°, contain 1,376 regions to be photographed, and that about 10,000 reference stars, distributed within these zones at the rate of three stars per square degree, whose positions had to be accurately determined by transit circle observations, were necessary, according to Mr. Cooke, for the preparation of his photographic catalogue.

 

To these two classes of work the Perth Observatory has practically devoted the whole of its energies and resources, and is still continuing on the same lines towards the completion of its allotted share.

 

The entire area covered by the Perth zones has been photographed, the whole series containing 1,376 plates, but Cooke found it desirable to obtain another series, in the taking of which improved methods were introduced, which gave greater uniformity in the results; 662 plates of the second series have been obtained and passed as satisfactory.

 

Three hundred and three plates of the first series, and 294 plates of the second series, have been measured.

 

In 1907, Professor Dyson, then Astronomer Royal for Scotland, offered to assist in the measurement of the Perth plates. His offer was gratefully accepted. The first plates sent to Edinburgh were those of zone -40 degrees. At present some 400 plates have been measured there and are practically completed (16).

 

It is stated by the present Acting Director that the series of plates comprising the Perth section of the photographic catalogue will be completed, in two or three years. None of the plates of the chart series have as yet been taken.

 

In the transit circle observations of the reference stars, Cooke adopted the zone method first introduced by Professor Kustner, of the Bonn Observatory in the observation of his zone stars.

 

The observed positions depend on three steps, namely .-

 

1. A fundamental catalogue of a small number of stars. For the present purpose Auwer's Fundamental Catalog fur Zonenheohachtungen am Sudhimmel has been used. This contains, on an average, about three or four stars per hour between the limits of -31° and -41° declination.

 

2. A catalogue of secondary standards, containing three or four stars per hour for every zone of two degrees between the above limits. The positions of these stars depend entirely upon those of the fundamental catalogue, and about ten observations of each star were taken. This catalogue has been published as the first volume of Perth observations, under the title of A Catalogue of 420 Standard Stars, etc.

 

3. The stars of this catalogue form the basis for the determination of positions of the reference stars, of which four catalogues were published, in 1908, 1909, 1910, and 1911.

 

The places of 7,561 stars for the epoch 1900 are contained in these catalogues.

 

The plan of advancing all the various phases of the photographic catalogue as rapidly as possible, by measuring the plates soon after they have been taken, and regulating the transit circle observations according to the requirements of the computers for determining plate constants, and thence the final preparation of manuscript for the printer, enabled Cooke to commence the publication of his section of the work in 1911. Vol. I. of the Astrographic Catalogue, 1900, Perth section -31° to -41°, and three other volumes bearing the same title, were issued in 1911 and 1912. In these are registered the rectilinear co-ordinates of 60,481 stars, in the aggregate, resulting from the measurement of 160 plates, which cover a belt round the heavens two degrees wide between 31 degrees and 33 degrees of south declination.

 

The present director estimates that the whole share of the Perth Observatory in the international astrophotographic work will be fully published by the end of the year 1918, so far as the catalogue series is concerned.

 

 

The Government Observatory of Brisbane, Queensland

 

The Astronomical Observatory at Brisbane may be said to have been established in the year 1879, when, subsequent to the death of Captain O'Reilly, a gentleman who had a private observatory at his home in South Brisbane, the Government of Queensland purchased his entire outfit, and removed the building to its present location on Wickham Terrace.

 

The adopted geographical position is - Latitude, 27° 28' 00" south; Longitude, 10h. 12m. 6.40s. east.

 

The various surveyors-general have successively controlled the Observatory programme of work. This has primarily been governed by the requirements of the Survey Department, and was an integral part of the operations of the trigonometrical survey during its existence. The taking of observations for time and the supervision of its distribution per medium of private lines, time ball, etc., is the only work now performed, and none other is projected under present conditions.

 

The astronomical equipment is as follows :-

 

(1) A portable transit instrument, by Troughton and Simms, of 30 inches focal length, and 2½ inches object glass. This instrument has been in use for about 30 years.

 

(2) A sidereal clock, by Cochrane, of Brisbane, with Riefler's pendulum, and seconds contact for transmitting clock beats electrically.

 

(3) Combination chronograph and Morse telegraph instrument, with relay, etc., for recording transits, transmitting and receiving time signals.

 

(4) A mean time clock, by Kullberg, of London, with seconds and hours contacts, also with electro-magnetic attachment for correcting small errors without touching the clock.

 

(5) Sidereal and mean time chronometers.

 

(6) Time-ball apparatus.

 

For a few years after the establishment of this Observatory the observations for time were made by the late Sir Augustus C. Gregory, a versatile and ingenious scientist and famous explorer, who having then retired from his position of Surveyor- General of Queensland, took up the work as a hobby and for this purpose constructed with his own hands a chronograph, relay, and all the apparatus necessary for electrically recording the observations, including the seconds contact in the sidereal clock.

 

 

Tasmania

 

In conjunction with the chief meteorological station of this State, a Government observatory was established at Hobart on a very modest scale (reduced indeed to a minimum as an astronomical institution) for the purpose of determining local time and supplying the public and the shipping at Hobart with a daily time signal. The astronomical equipment consisted of a small transit instrument and a time keeper, neither of these being of high class workmanship.

 

Owing to complaints made by the Admiralty, in regard to the occasional uncertainty of the time given by the Hobart Observatory, the Government of Tasmania arranged with the Victorian Government for the daily transmission of a time signal at 1 p.m. from the Melbourne Observatory, which has been used since 1911 for dropping the time ball at Hobart, and is repeated to other places in that State.

 

Thus the State of Tasmania is at present without official astronomy.

 

 

 

(c) Amateur Astronomy

 

 

The astronomical work considered under this heading is that which has been produced by Australians for the love of it and not for pay, nor as a discharge of official functions.

 

In the popular mind, amateur efforts are frequently associated with the idea of inferiority, but the persons who will be referred to in this division of Australian Astronomy need not fear that the adjective "amateur" is given to them with any intention on my part of underrating their abilities as astronomers or of placing them and their work in a class below that of officialdom. The name of John Tebbutt will be found amongst them. They are, therefore, in good company, and may well be proud of it.

 

The astronomical work done by Mr. John Tebbutt at his own observatory, Windsor, New South Wales, claims for him first place on the list of private citizens in Australia who have cultivated astronomy for its own sake.

 

His first contribution to the store of observed astronomical phenomena dates from 1854. His fame amongst astronomers the world over dates from his discovery of the Great Comet of 1861. His title to the full recognition of valuable service rendered for the credit of Australia and the advancement of astronomical science is based on a lifetime of assiduous and diligent observations of great accuracy and importance, extending over a period of more than half a century. Mr. Tebbutt is now an old man and has practically closed his career as an astronomer, and it seems just to remind Australians that they should lose no opportunity to honour this veteran observer

and to show an adequate appreciation of his merits.

 

Mr. Tebbutt, in his History and Description of the Windsor Observatory, written in 1887 (17), and in his later work, Astronomical Memoirs, written in 1908 (18), gives a full account of the Windsor Observatory and of the work done by him, from which the information contained in the following notes has been drawn, not infrequently in his own words.

 

 

Mr. John Tebbutt' s Observatory Windsor, New South Wales

 

(18) "At the eastern extremity of the municipal town of Windsor, lies the Peninsular Estate, a tract containing about 250 acres of the richest alluvial land. It is so called because it is nearly surrounded by the courses of the Hawkesbury River and its tributary, the South Creek, at their confluence. On a hill situated a little south-west of the middle of the estate, and whose summit is about 50 feet above the mean tide level," stands the residence of Mr. Tebbutt and his observatory, whose geographical position is - Latitude 33° 36' 30.8” south; Longitude 10h. 3m. 20.51s east.

 

Tebbutt's work begins in 1854. He was then 20 years of age. His equipment from 1854 to 1861 consisted of a sextant, artificial horizon, and a "common but excellent eight-day pendulum clock," and a telescope, If inches aperture. He chiefly employed these instruments for self training and "providing gratuitous information of a popular character for the daily newspapers." To these instruments were added a refracting telescope, by Jones, of 3¼ inches aperture and 48 inches focal length, in November, 1861; and an excellent eight-day half-second box chronometer by Parkinson and

Frodsham, in April, 1864. At the close of 1863, a small observatory was erected on the western side of his residence. It consisted of a small wooden building, comprising a transit room and a prime vertical room. An octagonal tower, rising from the centre of the building, served to accommodate the refracting telescope, which he himself mounted in 1864 "according to the Sisson or old English method." In the same year he installed also a transit instrument with object glass of 2.1 inches aperture, and 20 inches focal length, made for him by Tornaghi of Sydney. The local mean time was determined with this instrument for many years.

 

All extrameridional observations were made with the 3¼-inch telescope till 1872. This was provided with two ring micrometers made by Tornaghi, and eyepieces ranging in magnifying power from 30 to 120.

 

In 1874, he acquired an equatorial by Cooke and Son, of York, with object glass of 4½ inches aperture and 70 inches focal length, mounted according to Fraunhofer method.

 

In the same year a circular wooden building, 12 feet in diameter, was erected close to the observatory for the installation of this equatorial.

 

"In 1879 a substantial observatory of brick was erected on the south-west side of the old buildings," and the equatorial, together with a new transit instrument by Cooke and Son, were permanently mounted on solid masonry piers within the new building.

 

The object glass of the transit instrument has a clear aperture of 3 inches and a focal length of 35 inches.

 

Another fine chronometer by John Poole was acquired in 1882.

 

Finally, in 1887, to the equipment of Mr. Tebbutt's observatory was added a fine equatorial 8 inches aperture and 115 inches focal length, mounted on the Fraunhofer or German plan, and provided with all the usual requisites of a first-class instrument. It was made in 1882 by Grubb, of Dublin.

 

In the annual reports of his operations, of which he gives a methodical and faithful account from 1864 to 1907, it is shown that his astronomical activities were chiefly directed towards the comets and lunar occultations of stars, but he contributed also, throughout his career, to the study of the phenomena of Jupiter's satellites, the variability of special stars, such as η Argus, R Carinae, and others, and later, with his larger telescope, devoted much energy to micrometric comparisons of the major and minor planets with neighbouring stars and the observation of the more interesting southern binary stars.

 

His record of work on comets is remarkable. He began with the discovery of the Great Comet of 1861, which caused a sensation, not only on account of its brilliancy, but also because the earth passed through its tail. He observed the return of the celebrated Encke's comet in the following year, and on six other apparitions in the years 1865, 1875, 1878, 1888, 1894, and 1898, and on three or four occasions he was the first to detect it. In 1881 he discovered another comet, which became a fine object as it passed into the Northern Hemisphere, and is specially distinguished by being the first comet of which a satisfactory photograph was obtained and whose spectrum was satisfactorily studied.

 

Schaeberle's Comet 1881 V. was independently discovered by Tebbutt.

 

More than 40 other comets, mostly strangers to our system, were observed by Mr. Tebbutt, and followed night after night from the earliest opportunity to the last degree of visibility, determining for each a series of accurate positions, which were employed by him or by other astronomers for the computation of the orbits of these bodies. These observations often extended over several weeks - sometimes months. The comet discovered in America by Brooks, in 1892, was kept under observation at Windsor on 62 nights; the Coddington Pauly Comet of 1898, for 103 nights; and Halley's Comet, on 21 nights - from December, 1909 to July, 1910. In 1912 he made micrometric measures of Gale's Comet on nine nights.

 

From 1862 to 1906 he published 35 papers on Comets in the Monthly Notices of the R.A.S.; 73 papers in the A.N.; 18 in the Observatory; 5 in the B.A.A.; 2 in Transactions of the Philosophical Society of Neiv South Wales.

 

Such is Mr. Tebbutt's share of Australia's contribution to cometary astronomy.

 

Next in order on the initial programme of the Windsor Observatory come the Lunar Occultations of Stars. Systematic observations of this class were commenced in 1864 and were continued till 1904, and form part of the regular work of every year of this period, with very few exceptions. Between the years 1896 and 1900, 435 occultations were observed. This will give some idea of Mr. Tebbutt's activity in this branch.

 

His results of these observations have been widely utilized by astronomers in investigations of longitudes by absolute methods.

 

Tebbutt's results of occultations observed in the years 1864-1870 were in 1896 employed by Dr. Hugo Clemens, in a determination of the longitude of the Windsor Observatory, and formed the material for an inaugural dissertation entitled Bestimmung der Lange von Windsor, New South Wales, etc.

 

Similar results obtained from observations of the years 1873-1876 were used by Dr. Auwers in conjunction with those observed at Melbourne in 1874 and 1875, for the purpose of obtaining a fundamental meridian for Australia by absolute methods.

 

The longitude of Windsor, derived from Tebbutt's observations has the following values, viz. :-

 

Clemens, by observations of occultations, 1864-1870    - 10h. 3m. 21.25s.

Auwers, by observations of occultations, 1873-1876     - 10h. 3m. 20.60s.

By telegraphic methods                                              - 10h. 3m. 19.87s.

 

The third item which forms a considerable part of the regular work of the Windsor Observatory, is the systematic observation of the phenomena of Jupiter's satellites.

 

Records of this work are found in (at least) 25 different years.

 

"The Windsor observations of jovian eclipses from 1894 to 1899 were employed by Professor J. A. C. Oudemans, of Utrecht, in 1906, in his investigation on the mutual occultations and eclipses of the satellites of Jupiter in 1908."

 

The record of Mr. Tebbutt's work on variable stars consists chiefly of systematic observations of the well-known southern variables η Argus and R. Carinae.

 

η Argus was kept under observation every year from 1864 to 1876, and from 1880 to 1890, in which last year, according to Mr. Tebbutt, no further change was detected in its lustre.

 

R. Carinae was also regularly observed in each year from 1880 to 1890, and also in 1895 and succeeding years till 1898. During the period 1880-1890, ten maxima were recorded.

 

This series has proved very valuable in the investigation of the secular inequalities of the star.

 

The Windsor observations of double stars commenced in 1880. After 1887, when the larger instrument (the Grubb 8-inch refractor) was used, special attention was directed to the interesting southern binaries – α Centauri, γ Centauri, and γ Corona Australis, and to difficult southern pairs.

 

A large amount of other astronomical observations of a miscellaneous character must be credited to Mr. Tebbutt. Among these the more note-worthy are the transit of Venus of 1874, which was successfully observed at Windsor, and several transits of Mercury.

 

Many Lunar and Solar eclipses were observed by him, and his comparisons of the major planets and a score of the minor planets with neighbouring stars are very valuable.

 

In 1855, Mr. Francis Abbott, another enthusiastic amateur, was entering the field of observational astronomy in Tasmania. He erected a small observatory at Hobart, and provided it with a portable transit instrument of 24 inches focal length by Varley, and an achromatic telescope of 3½ inches aperture by Cooke and Son, and commenced observations for local time and observations on comets and variable stars. Later he improved his equipment by procuring a larger transit instrument by Dallmeyer, and an excellent telescope of 4½ inches aperture and 5 feet focal length by Dallmeyer, equatorially mounted. These he imported in 1862. A Dollond, 7-feet equatorial came into use soon after.

 

He was provided with a micrometer, a spectroscope, a standard clock, and a chronometer, and batteries of eye pieces ranging in power from 25 to 450.

 

He appears to have continued time determinations, for the benefit of himself and of the community, for a number of years, and his observations on comets and on the variable star η Argus are very numerous.

 

From 1861 to 1874 he contributed about thirteen papers to Monthly Notices, which included observations of Comets 1861 II., 1862 II., and 1865 I., this last comet having been discovered by him one day before Moesta discovered it at Santiago (19) (20). Observations of the transit of Mercury of 12th November, 1861 and 4th November, 1868, and many observations of the variable star η Argus.

 

Criticisms on these latter observations by Herschel, Airy, Lassell, Proctor, and others are published in Monthly Notices, Vol. 31 and 32.

 

He also contributed some twenty papers to the Proceedings of the R.S. of Tasmania in the years 1863-1874. Mr. Abbott died in February, 1883.

 

Tebbutt and Abbott are the earliest systematic observers in the history of amateur astronomy in Australia.

 

In this place the name of Ludwig Becker may be recorded as the observer who produced valuable drawings of the Donati Comet, 1858, which he made by means of an equatorial, forming part of the equipment of Neumayer's Magnetic Observatory, at Flagstaff Hill, Melbourne. These fine drawings are published in the Transactions of the Philosophical Institute (afterwards the Royal Society) of Victoria, Vol. 4, 1859.

 

The transit of Venus of 1874 gave the opportunity to several amateur observers in various parts of Australia to bring their work into public notice. Among these appear the names of T. D. Smeaton, F. C. Singleton, and A. W. Dobbie. The first two observed the transit at Adelaide, with small equatorials of 3½ and 3 inches aperture, and the third, with an 8½-inch reflector. Memoirs R.A.S., Vol. 47, 1882-3.

 

Mr. Dobbie, although his astronomical work was of an occasional character, for many years maintained a keen interest in astronomy. He was one of the observing members of the Mars section of the British Astronomical Association, and constructed his own reflecting telescopes. He completed one 18 inches aperture in 1905.

 

Two well-known observers who commenced astronomical work in the early seventies are the late Mr. W. J. MacDounell and Mr. G. D. Hirst.

 

Mr. MacDonnell was residing at Port Macquarie in 1871. He had an observatory there equipped with a 6-inch achromatic equatorial by Grubb, of Dublin, with which he made observations for a few years. Later he moved to Sydney, where, up to the time of his death, on 22nd September, 1910, he assiduously continued his astronomical observations with a 4¾-inch achromatic telescope by Parkes, of Birmingham, an excellent instrument, equatorially mounted and driven by clock work.

 

He observed the transit of Venus of 1874, as a member of one of the official parties stationed at Eden, under the Rev. Mr. Scott, once Director of the Sydney Observatory.

 

He was one of the observers of the Jupiter section of the British Astronomical Association up to the time of his death, and contributed several papers and notes to the Journal and Memoirs of that association, on Jupiter, on Halley's Comet, occultations and other subjects of a more general astronomical interest.

 

Mr. G. D. Hirst, of Sydney, is noted for his remarkable skill in astronomical drawings. He has been a member of the observing sections of Jupiter and Mars of the British Astronomical Association, and several of his beautiful drawings of these planets have been reproduced in the Memoirs of the Association.

 

The Director of the Mars observing section - M. Antoniadi, referring in one of his reports to the work of Mr. Hirst, says "The drawings of Mr. Hirst are coloured and represent the general appearance of the Planet (Mars) more faithfully than any others received during the apparition." (1905) Memoirs B.A.A., Vol. XVII., Part II.

 

Mr. Hirst used an achromatic telescope by Cooke, equatorially mounted, object glass 4½-inch aperture.

 

His work extends over a period of 40 years, and includes, in addition to studies of surface detail of Jupiter and Mars at several oppositions, observations of comets and double stars, the results of which, or of most of them, have been published in the Journal and Memoirs of the B.A.A. and in the Journal and Proceedings of the R.S. of New South Wales, to which societies he has contributed also various papers and notes on other subjects.

 

Among the private citizens interested in Australian astronomy not previously mentioned, whose contributions to it, or valuable services rendered to, in the period 1880-1890, should be placed on record, are the following :- In Tasmania, A. B. Biggs; In Victoria, Dr. Bone, David Ross, James Oddie; In Queensland, J. E. Davidson; In New South Wales H. F. Madsen, H. Watt, and H. Corbett.

 

The late Mr. Biggs was a judicious and ingenious observer, and some of his observing instruments and apparatus were made by himself. On the occasion of the transit of Venus of 1874, the assistance of Mr. Biggs was very highly appreciated by the observing party from the United States, at Campbelltown, in overcoming instrumental difficulties. The principal instrument with which he made his observations, especially in the years of his greater activity - 1883-1887 - was a reflecting telescope with mirror 8½ inches diameter.

 

He employed also a refractor of 3-inch aperture, and was provided with a sidereal clock, a chronometer, a small direct vision spectroscope by Browning, and other minor apparatus.

 

His subjects of observation were chiefly comets. The results of his work were published in the Monthly Notices of the R.A.S., Vol. 45, pp. 348 and 376.

 

He also contributed thirteen papers, bearing on astronomy, to the Proceedings of the R.S. of Tasmania, from 1884 to 1891.

 

The late Dr. Bone built a private observatory on his grounds at Castlemaine, Victoria, where in 1881 he installed an equatorial telescope with achromatic object glass 8-inch aperture, by Grubb, of Dublin, an excellent instrument, provided with all requisites for fine astronomical work.

 

He had this instrument mounted and in working order just in time for the transit of Venus of 1882, which he observed successfully. He had planned a useful programme of work for himself, which, however, was not to be carried out, for he died very shortly after.

 

But his telescope was destined to do good work for many years after him, in the hands of Mr. John Tebbutt, at the Windsor Observatory, by whom the instrument was bought.

 

Mr. David Ross, of Melbourne, in 1883, while watching the heavens for the expected periodical comet of Pons, discovered a small southern comet (1883 II.) His instrument was a small portable 3-inch achromatic telescope mounted on a short tripod. Later he constructed for himself a 6-inch reflecting telescope of the Newtonian type, which he mounted equatorially. He has employed it systematically during all these years, chiefly searching for comets; and in 1906, he made his second discovery of Comet 1906 II.

 

In 1887, Mr. James Oddie had erected at his own cost an observatory at Mount Pleasant, Ballarat, Victoria, which he equipped with various apparatus, chiefly reflecting telescopes locally constructed.

 

He engaged the services of the late Captain Baker, who at the time had become favourably known for his skill in making parabolic reflectors, and placed him in charge of the observatory.

 

A mirror 26 inches in diameter was completed by Captain Baker in 1891, which was mounted equatorially as a Newtonian telescope driven by clock-work. Another 12-inch Newtonian telescope was also mounted.

 

The observatory was provided with a small transit telescope, astronomical clock, and accessories.

 

The instruments were well housed in spacious wooden buildings which contained in addition to other apartments, a large lecture room.

 

In 1888, Mr. Oddie imported an excellent equatorial telescope with object glass 9 inches clear aperture and 135 inches focal length by Grubb, of Dublin, which, however, was never taken out of its packing cases.

 

This is the instrument which, in 1910, was presented by Mr. Oddie to the Commonwealth Government and subsequently erected .t the Mount Stromlo Observatory in the Federal Territory.

 

Mr. Oddie's observatory at Mount Pleasant, was chiefly intended for the education and entertainment of the public of Ballarat, and no astronomical work of a systematic character was ever done there. The observatory was dismantled in 1910.

 

On 21st July, 1889, Mr. J. Ewen Davidson, of Mackay, Queensland, made the discovery of Comet 1889 IV. by means of one of the telescopes used by the British Expedition under Captain Morris, E.E., for the observation of the transit of Venus, in December, 1882, at Jimbour, Queensland, and sold afterwards to Mr. Norris, of Townsville.

 

Several amateur makers of reflecting telescopes were very active during this decade, and contributed considerably to foster astronomical interest. These are -

 

R. W. Wigmore and R. Shafer, of Melbourne; Dobbie, of Adelaide; H. Watt, H. Corbett, Walter Gale, who commenced constructing his own telescopes in 1882 when he was still a school boy, and H. F. Madsen, of New South Wales; and others less well known.

 

Mr. H. F. Madsen's paper in the Proceedings of the Royal Society of New South Wales, upon the construction of a reflecting telescope of 18 inches aperture is a valuable contribution to the subject.

 

In later years, and up to the present time, we find the number of amateur observers and persons interested in the advancement of Australian astronomy gradually and widely increasing, and there are among them several names which have gained distinction through the value of their work.

 

Messrs. R. T. A. Innes and C. J. Merfield were at one time serving enthusiastically in the ranks of amateur astronomers in New South Wales - Innes till 1896, when he left Australia to take up an official position under Dr. Gill, at the Cape Observatory; and Merfield, till 1905, when he joined the Sydney Observatory. The work of these men, which was done in their amateur days, should be noted here.

 

Innes used a refractor of 6½-inch aperture, and a Newtonian reflector, with a mirror of 16 inches diameter, and carried on observations of variable stars and double stars; some of his results were published in the Monthly Notices of the R.A.S. and in the Journal of the British Astronomical Association. List of probable new double stars, and Occultation of Antares, 1894, 31st October, Monthly Notices, Vol. 55; on the proper motion of Lacaille, 4336, Monthly Notices, Vol. 56; new double stars, Journal of the British Astronomical Association, Vol. 6; observations made at Sydney in 1895; and observations of variable stars, 1895-96 ; and order of brightness of the 1st magnitude stars, Journal of the British Astronomical Association, Vol. 6, etc.

 

Innes contributed also papers on the secular perturbations of the Earth's orbit by Mars, Monthly Notices, Vol. 52; the secular perturbations of the Earth arising from the action of Venus, Monthly Notices, Vol. 53; elements of Comet 1894 (Gale, 1st April), A.N. 3231; Table to facilitate the application of Gauss's method of computing secular perturbations, Monthly Notices of the R.A.S., Vol. 154, and other writings.

 

Merfield employed a refractor of 6¼-inch aperture by Cooke, equatorially mounted; a reflector, equatorially mounted, mirror 7 inches diameter; a small transit circle, with object glass 2¼ inches aperture; chronometers; and a tape chronograph.

 

With this equipment he conducted systematic observations for several years, chiefly on coloured stars and comets.

 

Most of the astronomical data for the use of observers in New South Wales on special events, such as predictions of occultations, elements and ephemeris of newly discovered comets, ephemeris of expected periodical comets, times and explanatory notes of eclipses of the sun and of the moon, and other celestial phenomena of public interest were prepared very frequently by Innes, and later, from 1894 to 1905, very regularly and almost entirely by Merfield.

 

Gravitational astronomy was, however, the work in which Merfield was particularly interested, and to which he devoted most of the time he could spare from his ordinary daily occupation.

 

Amongst the most important of his papers on this and allied subjects, the following may be mentioned :- Definitive orbit elements of comet 1898 VII.; Definitive orbit elements of comet 1899 I.; Definitive orbit elements of comet 1901 I.; Secular perturbations of Eros arising from the actions of the eight major planets of the solar system; Determination of the secular perturbations of minor planet Ceres, arising from the actions of the eight major planets of the solar system; Secular perturbations of (7) Iris, arising from the actions of the eight major planets of the solar system; Secular perturbations of Ceres, arising from the action of Jupiter (with an important appendix on the co-efficients of the hypergeometrical series - F α β γ χ). Tables of the two hypergeometrical functions – F (1/6, 5/6, 2, sin2 i/2), and F (-1/6, 7/6, 2, sin2 i/2).

 

Walter F. Gale, one of the best known and most skilful observers of New South Wales, had been devoted to astronomical observations and the making of reflecting telescopes since 1882, but it was not till ten years later that he became possessed of a sufficiently suitable equipment for systematic work. In 1892, by means of an exquisitely defining reflecting telescope by With, of 8½ inches aperture, he made many observations, particularly of the planet Mars, which, with four drawings, were published in the Journal and Memoirs of the British Astronomical Association. This observer was the first, it appears, to note the delicate markings now known as the "oases" of Mars, as recorded by Flammarion and Antoniadi. In 1893 he observed the total eclipse of the sun at Mina Bronces, in Chile, and has since "chased" three other solar eclipses, but each time met with adverse weather conditions.

 

He also devoted much attention to Jupiter and his Galilean satellites, several hundreds of observations of which are published in the Memoirs of the B.A.A.

 

Mr. Gale has independently discovered six comets, two of which bear his name, namely :- Gale 1894 II., and Gale 1912 α.

 

Comet 1888 I., Sawerthal, was found by him independently only one day after Sawerthal had discovered it at the Cape, and the other three comets proved to be returns of periodical comets - Fabry 1886 I., Winnecke 1892 IV., and Tempel2 1894.

 

He also discovered several double stars and a ring nebula.

 

Notes upon these discoveries were published in the Astronomische Nachrichten, in the Monthly Notices of the R.A.S., and other journals.

 

Perhaps the best service rendered to Australian astronomy by Mr. Gale was the part he took in conjunction with Innes in forming the New South Wales branch of the British Astronomical Association.

 

This branch was constituted in September, 1894, when it consisted of thirteen

members, namely :- John Tebbutt, R. T. A. Innes, W. F. Gale, G. H. Knibbs, C. J. Merfield, H. Wright. G. Butterfield. C Mathews, F. D. Edmonds. R. D. Lewers, J. W. Askew, T. W. Craven, and C. C Carter. It made rapid progress and its roll of members gradually increased.

 

In 1895, a special section for the observation of coloured stars was first formed, with Merfield as director and two observers, namely - H. Wright, who employed a reflecting telescope of 8½ inches aperture; and F. K. McDonall, with a 2⅛-in. refractor; Merfield himself using a 7-in. reflector. Upwards of 5,000 observations were made of 458 stars in accordance with a carefully planned programme, which was completed in the years 1895-97. The results of this work are published in Vol. VI., No. 9, and Vol. VIII., No. 1 of the Journal B.A.A.

 

In 1897 special observing sections were formed as follow :- Comet section - Director, John Tebbutt; Jupiter section - Director, W. F. Gale; Sun and Meteors - Director, F. K. McDonall.

 

The first president of the branch was Mr. John Tebbutt, in which office he was followed by G. H. Knibbs, the present Commonwealth Statistician, who in the year 1900 prepared a paper on "The Sun's motion in Space," which was published in the Proceedings of the R.S. of New South Wales, Vol. XXXIV. It contains the history and bibliography of the subject from Giordano Bruno (1584) to Kobold (1900), and is qualified by the author as a step preliminary to a further consideration of the whole question, which however, his subsequent official duties prevented him from carrying out.

 

The paper, which bears clear evidence of a vast amount of careful research renders a complete account of the state of knowledge on the subject existing up to the year 1900, and forms an astronomical contribution of great value.

 

The third president (Session 1899-1900) was the Rev. Dr. Roseby, a fluent writer on astronomical subjects, and more particularly interested in gravitational astronomy. The elliptic elements of Gale Comet 1894 b, were computed by him.

 

Subsequent occupants of the chair were W. F. Gale, W. J. MacDonnell, G. D. Hirst, and C J. Merfield, whose work has already been separately referred to, and next to these come H. Wright (1907-1909), J. Nangle (1909-1911), and again the Rev. Dr. Roseby (1911-1913).

 

Mr. H. Wright has for a long time been devoted to astronomical observations, for which he uses a reflecting telescope of the Newtonian type, by Browning, 8h inches aperture equatorially mounted. Amongst the papers published in the Journal of the Association, containing the results of his work are the following :-  

 

Double star observations and observations of meteors. Vol. VI.;

Daylight occultation of Antares, Vol. VII.;

Chamber's catalogue of red stars, Vol. XI.;

 

Some southern nebulae and the trapezium of Orion, Vol. XII.; comet Moorehouse 1908 e, Vol. XIX.

 

He is a member of the "Jupiter" and "Mars" observing sections, and a number of his drawings and observations of these planets, also of Saturn and Halley's Comet, have been published in the Memoirs of the B.A.A. At one opposition of Mars there were only three southern observers, and his contribution carried considerable value and was highly appreciated. He has observed and sketched sun spots and solar prominences, and published several papers on astronomical subjects of a more general interest.

 

James Nangle is another practical observer of considerable merit and the possessor of a first-class achromatic telescope, by Cooke and Sons, of 6½-in. aperture, mounted equatorially and driven by clockwork, which had been used by Innes when a resident of Sydney.

 

The instrument is housed in a well-built and commodious observatory, where work is being done with efficiency and comfort.

 

The nature of his observations and the subjects in which he is more particularly interested are shown by his published results in the Journal of the Association, some of which I note here.

 

Double star measures. Vols. XVII. and XXI.

Measures of α Centauri, Vol. XIX.;

Measures of ρ Eridani, Lacaille 2145, Vols. XIX. and XX.;

Provisional orbits of ρ Eridani and h 5014, Vols. XIX.; and XXI.;

Orbit of β Muscae, Vol. XX.;

Cluster about K Crucis, Vols. XIX. and XVIII.;

Saturn's diameter. Vol. XVIII.;

Occultations of θ Librae and Uranus, Vol. XVIII.

 

The New South Wales branch of the B.A.A. is still in full working activity.

 

Of the total number of 76 Australian members of the parent association, more than one half belong to this branch.

 

Mr. E. H. Beattie, the present secretary, is also a contributor to the advancement of Australian amateur astronomy. He has a good observatory, equipped with an excellent equatorial refractor by Grubb, 6¼ inches aperture, driven by clockwork, and provided with all the accessories required for micrometric measurements. His principal observations are - occultation phenomena of Jupiter's satellites, double stars, comets, eclipses and occultations of stars and planets by the moon.

 

The results of his work, as well as his reports of work done by the branch generally, to the parent association have been and are being regularly published in the Journal of the B.A.A.

 

Mr. T. H. Close renders good service by computing comets' orbits and lunar occultations by graphical methods, and furnishing such data to those interested.

 

Other members of this branch figure in the Journal and Memoirs of the Association as members of some particular observing section, and as contributors of astronomical papers, notes, or drawings. These are J. E. Bell (Solar Section), H. Brown (Comet Halley), R. H. Bulkeley (Comet Halley), A. B. Cobham (Jupiter and Mars), the late Dr. R. D. Givin (Jupiter, Mars, and the Sun), Gr. H. Hoskins (Mars), J. C. Jenkinson (Auroral and Zodiacal light), F. K. McDonall (Meteors), D Shearer (Mars), Rev. W. Swindlehurst, P. Chauleur, Captain Edmonds, and Mr. N. J. Basnett, who specializes in meridian observations for the accurate determination of time.

 

For the published results of the above observers, see list in Appendix.

 

In 1897, a branch of the British Astronomical Association was formed in Victoria, and the attempt was made to encourage the possessors of astronomical telescopes to undertake systematic observations with them. The principal names of those who worked energetically in organizing and afterwards struggling to set the branch in working order are those of - R. W. Wigmore, the late Professor Kernot, Dr. E. F. J. Love, C Oliver. M.C.E., T. W. Fowler, M.C.E., Professor Barnard, Mrs. Rose Whiting, David Ross, and George Smale.

 

The inaugural meeting of the branch took place on the 16th December, 1897, under the presidency of the late R. L. J. Ellery, who held office till the year 1900, the chair being successively occupied after him by the Rev. John Meiklejohn, Dr. Love, Professor Kernot, and Professor Barnard.

 

R. W. Wigmore was secretary for the period (1897-1900), David Ross (1900-1901), and George Smale (1901-1905).

 

The difficulty which prevented the sound development of this branch and eventually caused its extinction at the end of 1905, was the failure to induce a sufficient number of its members to use their telescopes for some definite astronomical purpose, and in accordance with a suitably prepared plan.

 

Professor Barnard has been for many years interested in the observation of variable stars. He is at present in charge of a small observatory recently erected at the Royal Military College of the Commonwealth, on the summit of Mount Pleasant, near the Federal capital site.

 

The observatory is provided with an equatorial refractor, by Cooke and Sons, of 4½ inches aperture, and a portable transit instrument, and it is expected that Professor Barnard will be able to continue their regular observations on variable stars.

 

The object of this observatory is principally educational.

 

There is only one other State of the Commonwealth at present in which no Astronomical Society exists. This is South Australia.

 

The Astronomical Society of South Australia is intimately associated with the Adelaide Observatory. Until the end of 1906, it held its meetings at the Observatory, and although at present the members meet in another building, the Observatory instruments are still at their disposal, and in fact, the present director states "the observations of variable and double stars have now been commenced by certain members of the local Astronomical Society, the equatorial telescope of the Observatory being used for this purpose."

 

This society dates back to the year 1892, when as a section of the Royal Society of South Australia, it held its first meeting at the Adelaide Observatory, on the 5th April of that year, under the presidency of the late Sir Charles Todd.

 

The annual reports of the society show a considerable number of persons (40 or more) who have at some period been interested in astronomy, and among them there are several whose writings on astronomical subjects appeal in the Transactions of the society. (For the principal titles and references to these works, see Appendix B.) It does not appear, however, that astronomical observations of a systematic character have been made by any observer in South Australia for the object of carrying out a continuous and well-defined astronomical programme, though Mr. Sydney Manning, of McLaren Vale, has contributed observational notes on comets and the Kappa Crucis

cluster to the Journal of the B.A.A.

 

There are no records of astronomical results obtained by amateur astronomers in Queensland and Western Australia,, with the exception of those registered in the papers given in the Appendix.

 

 

 

(d) Australian Expeditions on Special Astronomical Occasions

 

 

There were five occasions upon which the official astronomers of Australia

recognised it as their duty to organize astronomical expeditions for observing

important astronomical phenomena at places remote from their permanent

observatories.

 

These occasions are  -  

 

1. The total eclipse of the sun of December, 1871  -  at Eclipse Island, off the extreme north of Australia;

 

2. The transit of Venus of December, 1874;

 

3. The transit of Venus of December, 1882;

 

4. The total eclipse of the sun of May, 1910  -  at Bruni Island, in the South Pacific ;

 

5. The total eclipse of the sun of April, 1911  -  at Vavau (Friendly Island) .

 

1. This eclipse occurred on the 11th December, 1871. The path of totality crossed the Gulf of Carpentaria, touching Australia near its extreme northern points.

 

The proposal to fit out an expedition to observe the eclipse was made by the late Professor Wilson, and, on the recommendation of the Royal Society of Victoria, the Governments of Victoria and New South Wales authorized their respective astronomers - R. L. J. Ellery and H. C. Russell - to organize a party of observers suitably equipped for the purpose.

 

The locality selected for observation was a small island off the north coast, called, since. Eclipse Island. The Queensland Government provided the, then new, steamer Governor Blackall to carry the expedition to its destination and back.

 

The party consisted of the principal assistants of the Melbourne and Sydney Observatories and a large number of other observers recruited amongst the most eligible in the colonies.

 

The expedition was provided with the 7¼-in. equatorial, by Merz, of the Sydney Observatory, upon which was mounted a camera with lens of 3 inches aperture and 30 inches focal length; the 4½-in. equatorial of the Melbourne Observatory, and several other smaller equatorial telescopes, all driven by clockwork; photographic and spectroscopic apparatus fitted for the purpose. Special instruments, adapted for the occasion, had been forwarded by the Eclipse Committee of the British Association for the service of the expedition.

 

The expedition started from Sydney on 27th November, 1871, reached Eclipse Island on 7th December, and had the instruments ready by the 10th December, the day before the eclipse. On the 11th, imfavorable weather prevailed, and the sky was overcast during the whole time of totality.

 

Thus the expedition failed in its main object.

 

2. For the observation of the transit of Venus, in 1874, the official astronomers of the time - Ellery, Russell, and Todd - organized various parties, which were sent to occupy favorable spots in their own respective colonies.

 

In the colony of Victoria, Ellery selected, in addition to the Melbourne Observatory, where he himself and his assistants observed the transit, three subsidiary stations. These were - Mornington, on the shores of Port Phillip Bay, and about 30 miles south of Melbourne; View Hill, Sandhurst, 86 miles north-west of Melbourne; Glenrowan, 150 miles north-east of Melbourne.

 

The observations at the Melbourne Observatory were directed by Ellery using the 8-in. equatorial, an 18-in. altazimuth, the Grubb 4-ft. reflector, and Dallmeyer's 4-in. photoheliograph. Good observations of internal contact at "Ingress" and "Egress" were obtained. Many micrometric measurements of diameter of Venus were made by a double image micrometer, and physical phenomena well observed. Several photographs were secured, both with the photoheliograph and the great telescope.

 

The party at Mornington was in charge of Professor Wilson, of the Melbourne University; its equipment consisted of a 4½-in. equatorial, by Troughton and Simms, with which micrometric measurements and contact observations were made; fair results of “Ingress" and "Egress" phenomena were obtained.

 

At View Hill, Sandhurst, Mr. C. Moerlin (assistant of the Melbourne Observatory) directed the operations. The instrument employed was an equatorially-mounted telescope, with objective 6¾-in. aperture, by Ertel, of Munich, provided with a double image micrometer. Cloudy weather prevented contact observations at "Ingress", but some satisfactory results of "Egress" phenomena were obtained.

 

At Glenrowan, the party was in charge of Messrs. A. C Allan and James Gilbert. The instruments employed were a 4½-in. equatorial, by Cooke and Sons, and a reflecting telescope, by Browning, 8½-in. aperture, equatorially mounted. Observations of "Ingress" were made satisfactorily in clear weather, except the first external contact, but no observations of "Egress" could be made, the sky being overcast.

 

In New South Wales, Russell, with the aid of the local Royal Society, was able to obtain sufficient encouragement and assistance from his Government to carry out the extensive preparations which he had planned with the object of securing observations on the eventful day of 9th December, 1874, at four different places in his colony. (6)

 

These were  -  

 

The Sydney Observatory;

Eden, on the north shore of Twofold Bay, 350 miles south-west of Sydney;

Goulburn, 134 miles south-west of Sydney, 2,071 feet above sea level;

Woodford, in the mountainous district, 50 miles west of Sydney.

 

Parties were despatched to these places equipped with equatorially- mounted telescopes, fitted with apparatus for photographing the sun, and provided with means for determining time, material for obtaining upward of 200 pictures of the sun, observing huts, and all necessary appliances.

 

(21) At Sydney, the observers were directed by Russell; the instruments employed were the 11.4-in. equatorial, by Schroeder, fitted with photographic apparatus, which could be quickly removed and mounted again; a 4¾-in. equatorial, by Troughton and Simms; and a 10-in. Browning silvered glass reflector.

 

At Eden, the Rev. W. Scott conducted the work; the instruments used were a 7¼-in. equatorial, and two other smaller achromatic telescopes, with objectives 4¼ inches and 3½ inches aperture respectively.

 

The station at Goulburn was occupied by Captain Hixson; this party was provided with an achromatic telescope of 6 inches aperture, equatorially mounted and fitted with a camera; also two smaller equatorial refractors of 3¾ inches and 3¼ inches aperture.

 

At Woodford, the observing party was in charge of Surveyor-General Adams. The observations were made with 3½-in. equatorial, and a 4-in. photoheliograph was employed for obtaining pictures of the sun. This station, in addition to the provisions made as at the other three places for taking 220 pictures, had a supply of 30 Janssen plates, each to hold 60 pictures.

 

Mr. Tebbutt observed the transit independently at his observatory, Windsor, with a 4½-in. equatorial. He had fine weather, and obtained accurate times of the beginning and end of the transit. (18)  

 

In South Australia the transit was observed -

 

By Mr. Todd, at the Adelaide Observatory, the instruments used being the 8-in. equatorial, by T. Cooke and Sons, and a camera arranged to give an enlarged picture of the sun.

By T. D. Smeaton, J.P., at his residence. North Adelaide, using an excellent 3½-inch equatorial by Cooke and Son.

 

By F. C. Singleton, on the grounds of the Adelaide Observatory, using a 3-in. equatorial.

 

By A. W. Dobbie, at his residence, 2 miles north-east of the Adelaide Observatory, using an 8½-in. silvered glass reflecting telescope.

 

The weather was unfavorable at Adelaide up to a short time after "Ingress" and was only intermittently clear afterwards.

 

Todd obtained a few micrometric measurements, and made some observations of the approach of internal contact at "Egress."

 

Messrs. Smeaton, Singleton, and Dobbie were able to observe and record the times of internal and external contact at "Egress".

 

On the whole, Australia acquitted itself with credit on the occasion of the transit of Venus of 1874, and the Australian results form an important part in the investigation of the solar parallax, based on the observations of this transit.

 

3. The Australians had no opportunity of observing the complete set of phenomena of the transit of Venus of 7th December, 1882, as the beginning of the transit took place before sunrise. The importance of securing observations of the other phases was, however, fully understood, and extensive preparations were made accordingly.

 

In Victoria, Ellery sent out two parties from the Melbourne Observatory - one to Hobart, and one to Sale, Gippsland - Ellery himself remaining stationed at the Observatory in Melbourne.

 

The instruments employed at these three stations were the same as those with which observations of the previous transit had been made.

 

Ellery and White had fine weather and obtained good results.

 

The weather in Gippsland was unfavorable, and no observations of any part of the transit were made.

 

In New South Wales, Russell organized, equipped, and trained five expeditions, which he was able to supply in each case with two equatorially-mounted telescopes of 6-inch and 4½-inch aperture. Fifteen observers took part in the work. The five stations occupied by these parties were Port Macquarie, Clarence River, Dromedary, Katoomba, and Lord Howe Island. Russell and his staff were stationed at the Sydney Observatory.

 

None of these parties were successful, owing to adverse weather conditions.

 

Tebbutt, at the Windsor Observatory, met with similar ill fortune. Thus no contribution was made by New South Wales observers upon the transit of Venus of December, 1882.

 

The Government Astronomer of South Australia - Mr. Todd - observed the transit at Wentworth with a 4½-inch equatorial. He met with fine weather, and his programme of observations was successfully carried out. (15)

 

4. The southern parts of Tasmania and Bruni Island were the only localities from which the total eclipse of the sun of 9th May, 1910, could be seen. The chance of successfully observing this eclipse was very small on account of the low altitude of the sun at the time of totality, and of the unfavourable and severe weather conditions generally prevailing in these particular localities so late in the autumn. It was known that, owing probably to this uncertainty and to the great length of the journey involved, no official expedition was to be despatched to Tasmania on this occasion, and only one private party, conducted by Mr. Frank McClean, was expected to come out in due course to occupy some spot within the belt of totality.

 

Under the circumstances it was clearly the duty of Australian astronomers to deal with the Tasmanian eclipse.

 

Dr. W. G. Duffield, of South Australia, now Professor of Natural Philosophy at the University College of Reading, brought this matter before the Council of the Australasian Association for the Advancement of Science at its Brisbane meeting, of January, 1909, and that Council appointed a committee, with Dr. Duffield as secretary, for the purpose of taking steps to ensure that efficient preparations were made to observe the eclipse in question. The result was that the Government of Victoria provided its own astronomer with the required means for organizing and fitting out an eclipse expedition to Bruni Island, which was done.

 

The Joint Permanent Eclipse Committee of the Royal Society and Royal Astronomical Society supplied a part of the equipment to this expedition.

 

Unfortunately it is needless to detail the elaborate preparations made since the day remained completely overcast, and nothing was seen of the eclipse, except a general darkening of the landscape.

 

Mr. Frank McClean and his party, who were stationed at Port Davey, some 60 miles to the west of us, and Mr. Walter Gale, of Sydney, who had purposely gone to Hobart on his own initiative to observe the eclipse from a position in that city, were also unable to see the eclipse owing to cloud and rain.

 

5. At the Sydney meeting of the Australasian Association for the Advancement of Science, in January, 1911, the same Eclipse Committee was reappointed with the object of forming an Australian expedition for the observation of the total eclipse of the sun of 29th April, 1911, at Vavau, one of the islands of the Tonga Group in the Pacific Ocean. Dr. Duffield being in Europe, Professor Moors, of the Sydney University, was appointed secretary to the committee.

 

The committee, having succeeded in obtaining a subsidy of £500 from the Commonwealth, was able to organize and equip a party.

 

The equipment of the expedition comprised principally -  

4-inch photoheliograph (Melbourne Observatory);

4½-inch equatorial telescope (Melbourne Observatory), with two large portrait lens cameras attached;

One coronograph (Perth Observatory);

One coronograph (Adelaide Observatory);

One 16-inch coelostat, lent by the British Eclipse Committee;

One 12-inch coelostat, lent by the British Eclipse Committee;

One coronograph (Sydney University);

One 6-inch refracting telescope, with camera attached;

One smaller equatorial;

A large altazimuth, for time determination (Perth Observatory);

Also several cameras of various sizes, chronometers, subsidiary apparatus, observing sheds and huts, living tents, and camp material.

 

On the morning of the eclipse all instruments were in good order and adjustment and the observers had been thoroughly drilled.

 

The weather was unpromising, and the face of the sun was obscured intermittently by passing clouds up to the beginning, and during a considerable part, of the phase of totality. Each observer, however, accomplished his allotted programme, and some 45 plates were exposed during the three and a half minutes of totality. The plates were developed the same evening, and the results obtained were found to be much better than was at first expected.

 

The form of the corona was found to correspond to the type which had been observed on several previous years of minimum solar spots.

 

Although this single result brings no new knowledge of eclipse phenomena, yet, taken as additional evidence concerning an important characteristic of the solar corona which is obtainable only on relatively rare occasions, it becomes a valuable contribution to the store of eclipse records.

 

 

 

(e) Determinations of Australian Longitudes.

 

 

Until the year 1883 the adopted fundamental meridians of Australia were those of the Observatories of Sydney and Melbourne, and the longitude assigned to these meridians depended on the observation of "moon culminations" and "moon culminating stars."

 

Until these two Observatories came into existence, the fundamental meridian of Australia was that which passes through Fort Macquarie, on one of the picturesque headlands of Sydney Harbor.

 

The longitude of this meridian was derived chiefly from the lunar observations of the early navigators, from Captain Cook in 1770 to Admiral King in 1817, and, later, to Sir Thomas Brisbane, Rumker, and others; the results of these observers fluctuated over a wide range which, however; is quite compatible with the conditions of the time.

 

Fort Macquarie was one of the points on the longitude circuit measured all round the globe by transportation of chronometers during Captain Fitzroy's famous voyage in H.M.S. ‘Beagle’ in 1831-36. The longitude found for Fort Macquarie was 10h. 4m. 32.14s., and if the correction 0s.115t = + 20.52s. as proposed by Dr. Auwers (22) be applied to it, it becomes 10.4.52.66, which is only 0.75s. in excess of what may be considered the most probable value of the longitude of this point at the present day.

 

The meridian of Fort Macquarie remained for many years the basis from which explorers and surveyors established geographical positions inland and originally ascertained the meridional subdivisions of the Australian Colonies geodetically or by transportation of chronometers.

 

One of the earliest and most interesting undertakings of this kind was the definition of the 141st meridian of east longitude, which was proclaimed as the eastern boundary of the Colony of South Australia by an Act of King William IV. in 1834.

 

In 1839, owing to the discrepant positions assigned to this meridian on different maps of the time, Mr. Surveyor C. J. Tyers was commissioned by Sir George Gipps, Governor of New South Wales, to ascertain its true place.

 

Tyers, adopting as his base the longitude of Fort Macquarie as 151° 15' 14" = 10h. 5m. 0.93s., determined the longitude of a point on Batman's Hill, near Melbourne, by transportation of chronometers, and thence by triangulation with a small theodolite fixed the position of the 141st meridian, which he verified by sextant observations of lunar distances.

 

Captain Owen Stanley recalculated Tyers' work, and the result he arrived at differed by only 16.2" from that of Tyers.

 

Tyers, having adopted a longitude base, which, according to more modern determinations, was more than 2 miles in error, and having carried out his own work with all the accuracy which was possible under the circumstances, the consequence was that the boundary was fixed, and afterwards (in 1847) actually marked on the ground more than 2 miles to the west of the 141st meridian east of Greenwich.

 

The longitude of the Parramatta Observatory was determined by Rumker by transit observations of the moon and moon culminating stars. Its value is given in the Philosophical Transactions for 1829 as 10h. 4m. 6.25s.

 

In ‘M.N. of the R.A.S.’, Vol. VI., page 213, Rumker, rediscussing his Parramatta observations, gives as a corrected value of this longitude 10h. 4m. 7.217s.

 

The first value of the longitude of the Sydney Observatory was obtained by the Rev. W. Scott in 1858, and was derived from the observations of 21 transits of the moon. The result was 10h. 4m. 49.0s.

 

In 1859 Mr. Scott observed 38 moon culminations which gave as the resulting longitude of the Sydney Observatory 10h. 4m. 59.86s (23)

 

Similar observations, 50 in 1860, and 56 in 1861, furnished the value 10h. 5m. 6.84s. (25)

 

Stone, from a rediscussion of Scott's moon culminations, observed at Sydney in the years 1859 and 1860, obtained longitude of Sydney Observatory 10h. 4m. 47.32s. (24)

 

In 1861 the first determination was made of the difference of longitude between the Observatories of Sydney and Williamstown by the telegraphic exchange of clock signals, and the value obtained was Sydney-Williamstown 0h. 24m. 55.38s. (26)

 

The longitude of the Williamstown Observatory was determined by the observations of moon culminations in the years 1860, 1861, and 1862, the adopted result being 9h. 39m. 38.8s. E. (11)

 

The difference of longitude between the Williamstown and the Melbourne Observatories was found by accurate triangulation to be 16.00s., giving for the longitude of the Melbourne Observatory 9h. 39m. 54.8s. (27)

 

This value was adopted and used until the year 1883.

 

In 1867 the difference of longitude between the Observatories of Melbourne and Adelaide was measured by telegraphic exchange of clock signals, giving the result 0h. 25m. 33.76s., which, being applied to the longitude of Melbourne, gave longitude of Adelaide Observatory 9h. 14m 21s., which value was adopted, and remained unaltered till 1883. (28)

 

Soon after the longitudes of the Sydney and Melbourne Observatories had been determined from lunar observations, it became evident that the longitude of the earlier fundamental meridian of Fort Macquarie, adopted by Tyers, was considerably too great, and that, consequently, the boundary between the Colonies of Victoria and South Australia had, very probably, been marked too far west, and the error was further verified by the results of the trigonometrical survey of Victoria, which connected the Melbourne Observatory with a western station of the survey near the South Australian boundary.

 

It thus became an important matter to ascertain the position of the 141st meridian by a fresh determination, and the Governments concerned ordered the work to be done by the Government Astronomers of the respective States.

 

The plan adopted by Todd, Ellery, and Smalley was to determine the difference of longitude by the exchange of time signals by telegraph between a temporary Observatory, erected for the purpose, near the northern end of the marked boundary, and the Observatories of Sydney and Melbourne. Todd occupied the station at the boundary, using the transit instrument by Troughton and Simms, of 3½-in. aperture, which had been used at Adelaide. Smalley operated at the Sydney Observatory, and Chief Assistant White at Melbourne Observatory.

 

On 9th May and 10th May the transits of ten stars, over the meridian of the Observatories at Sydney and at the boundary, were recorded simultaneously at both stations, and on 13th and 14th May the transits of 21 stars were similarly recorded at the boundary and at Melbourne Observatory. Exchange of time signals was effected also between the two Observatories of Melbourne and Sydney.

 

The results were as follow : -

 

Difference of longitude -                                h.    m.   s.

 

Boundary-Sydney .. .. ..                                0     40   59.72

 

Boundary-Melbourne . . . . ..                          0     16   03.77

 

Melbourne -Sydney .. .. ..                              0     24   55.81

 

The adopted longitude for Melbourne was . .   9     39   54.80

 

The adopted longitude for Sydney was . . . .   10   04   48.97

 

The adopted longitude for Sydney was the mean of the value 10h. 4m. 47.32s. calculated by Stone from Scott's lunar observations of 1859 and 1860 (24), and the value found by applying the difference Sydney-Melbourne 0h. 24m. 55.81s. to the longitude of Melbourne Observatory 9h. 39m. 54.8s.

 

From these data, and the measurement, by chaining, of the short distance between Todd's transit instrument and the boundary, it was found that the north end of the marked boundary line was about 2¼ miles to the west of the 141st meridian.

 

In the light of the present experience the longitude operations of 1868 can hardly be regarded as fundamental, and, moreover, the adopted longitudes of the Observatories of Melbourne and Sydney being at the time entirely dependent on transit observations of the moon, were not entitled to great confidence. Yet the means and methods employed in this later determination were so far superior to those of 1839 that a considerable error in the position of this boundary line, amounting to probably more than 2 miles, could be accepted as a tolerably well ascertained fact.

 

Then commenced the dispute between the adjoining States of South Australia and Victoria, the former claiming the strip of land upon which the latter State was encroaching. And the dispute grew even more vigorously after 1883, when the chain of telegraphically determined longitudes between Greenwich and Australia was completed; and further confirmed within sufficiently narrow limits the results of 1868. Eventually, in February, 1911, the case was taken before the High Court of Australia, which decided that the marked boundary having been accepted as such by the two States concerned, the fact that it did not exactly coincide with the 141st meridian

of east longitude did not warrant the Court in ordering the re-adjustment claimed by South Australia.

 

In 1882 an arrangement was made between the British and Australian authorities that Captain L. Darwin, R.E., should go to Singapore for the purpose of carrying out, in co-operation with an Australian observer, who was to be stationed at Port Darwin, a determination of the difference of longitude between the two places, by the exchange of clock signals through the cable lines of the Eastern Extension Company, thus completing the longitude chain Greenwich-Australia by the telegraphic method.

 

The writer was sent to Port Darwin equipped with a transit instrument, by Troughton and Simms, of 3-in. aperture, clock, chronometers, and all necessary requisites.

 

Captain Darwin, similarly provided with the necessary instruments, established his temporary Observatory at Singapore.

 

Captain Helb, of the Netherland India Staff of Batavia, was instructed by his Government to proceed to Banjoewangie, where the two branches of the cable between Port Darwin and Singapore join, and to take part in the longitude operations, so as to determine the intervals Banjoewangie-Singapore and Banjoewangie-Port Darwin, as well as the direct interval Singapore-Port Darwin.

 

Clock signals were exchanged by Port Darwin with Banjoewangie on 4 nights, with Singapore on 8 nights, with Adelaide on 6 nights, and with Melbourne on 4 nights, between the dates 28th January and 2nd March, 1883, inclusive.

 

By these operations the meridian of Port Darwin became the origin of Australian longitudes, and the following results were obtained and adopted at the time (26): -

 

h.   m.   s.

Longitude of Port Darwin                                      08   43   22.49

Longitude of Adelaide Observatory                        09   14   20.30

Longitude of Melbourne Observatory                     09   39   54.14 

Longitude of Sydney Observatory                         10   04   49.54

Longitude of Hobart (Barrack Square)                   09   49   19.80

 

A comparison of the telegraphic values of 1883 with those derived by absolute methods up to that time showed a more satisfactory agreement than could reasonably be expected.

 

Before dealing with the comparison, it will be necessary first to point out some results obtained by the method of occupations and culminations which have not yet been taken into account.

 

Russell observed a large number of transits of the moon and moon culminating stars in the years 1863, 1871, 1872, 1873, and 1874, from which he derived the value 10h. 4m. 50.81s. for the longitude of the Sydney Observatory, which he adopted from 1878. (29)

 

More transits of the moon and a number of occupations were observed at the Melbourne Observatory in the years 1874-75 for further verification of the adopted longitude, which confirmed the previously adopted value.

 

Also, Mr. John Tebbutt had very regularly observed many occultations of stars by the moon, and laid great stress upon the superior value of this method for improving the longitude of the Sydney Observatory and his own.

 

From 1863 to 1867 he had observed some 169 occultations, and by the end of the year 1878 had increased the number by 63 more, and having in the meantime determined the difference of longitude between his Observatory and that of Sydney, on several occasions, both by direct exchange of time signals telegraphically and by transportation of his chronometer, deduced the value of the longitude of Sydney Observatory based entirely on his own observations as follows : -

 

h.   m.   s.

Longitude of Windsor .. .. ..                                  10   03   21.81

Difference Windsor-Sydney .. ..                            00   01   28.83

 

Longitude of Sydney Observatory ..                      10   04   50.64 (30)

 

In 1884 Dr. Auwers deduced a fundamental value of the longitude of the Sydney Observatory based on the Australian observations both of transits of the moon and occultations (31). He found longitude of -

 

h.   m.   s.

Sydney Observatory .. .. ..                                   10   04   49.60

Melbourne Observatory .. .. ..                               09   39   54.17

Windsor Observatory . . . . ..                                10   03   20.77

 

The comparison of results depending on the entire chain of telegraphic longitudes completed in 1883 with those derived by Dr. Auwers from lunar observations shows a discrepancy amounting to less than one-quarter of second of time, which was justly regarded as a nearly perfect agreement.

 

Subsequent longitude operations in Australia until the year 1903 were confined to those specified as follow : -

 

A re -determination in 1887 of the arcs Windsor-Melbourne and Windsor-Sydney by telegraph exchange of time signals which gave -

 

m.   s.

Windsor-Sydney .. .. .. ..                                             01   29.39

Windsor-Melbourne .. .. ..                                           23   25.87

 

Melbourne-Sydney computed .. ..                                24   55.26 (32)

 

A re-determination in 1887 of the interval Windsor-Sydney by transportation of chronometer on seven different dates and by triangulation, giving two new values for this, are as follow : -

 

Windsor-Sydney  -                                                     m.   s.

By transportation of chronometer ..                             01   29.49 (18)

By triangulation .. .. ..                                                 01   29.77 (32)

 

Determinations of the longitude of the Brisbane Observatory, Queensland, by exchange of time signals telegraphically between Sydney and Brisbane in the years 1884, 1891, and 1892.

 

Determination of the longitude of Broome, Fremantle, and Albany, Western Australia, in 1890 and 1891, by telegraphic exchange of clock signals between Commander Moore and Lieut. Parry at the above stations and the Adelaide Observatory.

 

Determination of the longitude of the Perth Observatory in 1899 and 1901 by exchange of clock signals telegraphically with Adelaide and Melbourne.

 

The resulting longitude of the Perth Observatory being based on the value 9h. 14m. 20.30s. for Adelaide and 9h. 39m. 54.14s. for Melbourne, giving -

 

Longitude of Perth Observatory -                          h.    m.   s.

 

Via Adelaide (1899) .. .. ..                                    07   43   21.74 E. (33)

Via Melbourne (1899) .. .. ..                                 07   43   21.78 E. (33)

Via Adelaide (1901) .. .. ..                                    07   43   21.97 E. (34)

 

Determination of the longitude of a number of stations of the trigonometrical surveys of the States of New South Wales, Queensland, and Western Australia by telegraph exchange of time signals with the respective State Observatories.

 

The results of all these operations still depended on the value assigned to the longitude of the initial Meridian of Port Darwin in 1883.

 

"The laying of the cable across the Pacific Ocean from Vancouver to Australia and New Zealand, some 8,273 nautical miles in length, was completed towards the end of the year 1902. It connects three intermediate stations on its course, namely. Fanning Island, Suva (Fiji), and Norfolk Island, and branches from Norfolk Island to Southport, in Queensland (Australia), and to Doubtless Bay (New Zealand)." (35)

 

"The importance of taking advantage of the first opportunity of determining the difference of longitude between Canada and Australia, along this route, was quickly recognised by the Canadian astronomers who, having previously established a chain of longitudes across the Atlantic between Greenwich and Canada, could now continue the chain to Australia to meet the end of the chain carried eastward from Greenwich to Port Darwin, thus closing a complete longitude circuit round the earth."

 

"The work having been authorized by the Canadian Government, Dr. Klotz, of the Ottawa Observatory, was commissioned to take charge of it, and in March, 1903, in conjunction with his assistant, Mr. F. W. O. Werry, B.A., Dr. Klotz commenced his great series of Trans-Pacific longitudes, which he concluded in January, 1904."

 

The results of Dr. Klotz are as follows (39) -            h.    m.   s.

 

Adopted longitude of Vancouver .. ..                            08   12   28.368 W.

Interval Vancouver-Fanning Island . .                   02   25   05.406

Interval Fanning Island-Suva (Fiji) ..                           01   28   43.837

Interval Suva-Norfolk Island .. ..                           00   42   01.243

Interval Norfolk Island-Southport (Queensland) .. 00   58   01.364

 

13   46   20.218 W.

Longitude of Southport (Queensland) . .                10   13   39.782 E.

 

A second fundamental meridian was thus established in 1903 on the eastern coast of Australia, the longitude of which was based entirely on the telegraphic method, and was quite independent of any other Australian longitude previously determined.

 

The arc Southport -Sydney having been measured by exchange of clock signals between Klotz and the officials of the Sydney Observatory, the entire circuit round the earth was thus closed, and a comparison of the two independent values for Sydney, based on the eastward and westward chains from Greenwich, gave the closing error.

 

At the time when the comparison was made (1903) a re-discussion of the Port Darwin longitude, based on all available records up to 1894, had been made (36), according to which the adopted value 8h. 43m. 22.49s. required to be reduced to 8h. 43m. 22.34s.

 

Also in the years 1894-96 the interval Greenwich-Madras was re-measured by Colonel Burrard and Colonel Lennox Conyngham, which involved a further reduction of 0.04s., and finally in 1903 a re-determination of the arc Greenwich-Potsdam and the re -adjustment of European longitudes by Dr. Albrecht and Prof. Wanach (37) (38) showed that the reduction had been carried too far by 0.01s.

 

The values adopted by Klotz in his comparison were -

 

Longitude of Sydney -                                                h.    m.   s.

Via Eastern chain from Greenwich ..                             10   04   49.355

Via Canada and Trans-Pacific longitudes                       10   04   49.287

 

Closing error = 1.02" = 84 feet =                                00   00   00.068 (39)

 

On the basis of all data available at the present time, the most probable longitude values of those Australian stations which form part of the Canadian circuit may be assumed to be -

h.   m.   s.

 

Longitude of Port Darwin . . .. ..                                         08   43        22.28 E.

Longitude of Melbourne Observatory ..                         09   39   53.93 E.

Longitude of Sydney Observatory . . ..                         10   04   49.33 E.

Southport (Queensland) .. .. ..                                    10   13   39.82 E.

 

Notwithstanding the remarkable agreement of independent results obtained by absolute and telegraphic methods in the determination of Australian longitudes, and the powerful check afforded by the closing error of the Trans-Pacific chain, it has been pointed out (35) that such evidence cannot as yet be accepted as the measure of the accuracy of the last longitude values just given above; and that a re-measurement of the intervals Southport-Sydney, Sydney-Melbourne, Melbourne-Port Darwin, Port Darwin-Singapore, Singapore-Madras is required before these values can be adopted with full confidence.

 

The Commonwealth Government is desirous of establishing a primary meridian to which all the Australian longitudes should be referred for the purpose of connecting the various surveys of the States to a common meridian datum. The present Federal Observatory of Mt. Stromlo is indicated as the appropriate point for the primary meridian of Australia. Indeed, this was one of the reasons for which Mt. Stromlo was selected as the site for the Observatory. This point could be very readily connected with one of the existing Observatories - Melbourne or Sydney - telegraphically or geodetically, but it has been suggested to the authorities (35) that adequate precision in the determination of the longitude of this meridian could only be obtained

by completing a system of longitude measurements connecting Mt. Stromlo directly with the end of the Trans-Pacific chain at Southport on one side, and with the end of the Indian chain at Port Darwin on the other, and by re-measuring the intervals Port Darwin-Singapore and Singapore -Madras.

 

Great stress has been laid on the importance of carrying out this work soon and with due efficiency, in order to strengthen Australian longitudes .

 

 

The Mt. Stromlo Observatory

 

In the beginning of the year 1910 the Government of the Commonwealth decided to erect a temporary Observatory at Mt. Stromlo, within the Federal Territory, at a distance of 7 miles to the westward of the centre of the Federal Capital " Canberra."

 

The immediate object was to test by astronomical and meteorological observations extending over one year, whether the atmospheric conditions of the site were sufficiently favorable to justify the authorities to establish on that site a permanent Astronomical Observatory of the highest order.

 

In due course an appropriate structure was constructed for the installation of a 9-in. refracting telescope equatorially mounted, and periodical observations were made for a few days in each month for nearly two years at the end of which (July, 1913) the observers reported that the site was favorable for the intended purpose .

 

The selected site is the summit of a group of hills rising, by gentle and graceful slopes, to an elevation of some 600 feet above the general surface of the surrounding country, and 2,660 above sea level. It commands an uninterrupted view practically down to the horizon on all sides, it affords ample room for a great institution, and its orientation, in respect of the city and of the prevailing winds, is favorable.

 

The temporary building consists of a central dome, 18 feet in diameter, resting on a circular wall of concrete, 8 feet above the floor, and four small square rooms symmetrically placed north, south, east, and west for the accommodation of the observers and caretaker.

 

The Oddie telescope, which has already been noted in connexion with the private Observatory of Mt. Pleasant, Ballarat, is the principal instrument. It has an object glass of 9-in. aperture giving excellent definition. The telescope is mounted on a massive cast-iron stand, resting on a pier of concrete built on a granite foundation. A metallic camera is attached in which is fitted one of Dallmeyer's portrait lens of 6-in. diameter and 38 inches focal length. The instrument is provided with a fine driving

clock, excellent filar micrometer, electric illumination for dark or bright field, an Evershed prominence spectroscope made by Hilger, and every requisite for all classes of observations. The eye pieces range in power from 60 to 700.

 

This instrument was presented to the Commonwealth Government by the late Mr. James Oddie, of Ballarat, in July, 1910. I was commissioned to take delivery of it at Ballarat, and to erect it at Mt. Stromlo for the object stated above. As the instrument had never been taken out of its packing cases since the maker sent it out to Australia a quarter of a century before, it required a great deal of overhauling, and also several alterations and additions, which were done at the Melbourne Observatory.

 

The installation of the instrument at Mt. Stromlo was completed in September, 1911, after which observations were commenced and continued by myself and my chief assistant. Dr. J. Baldwin, during fifteen visits to the locality between 8th September, 1911, and 2nd June, 1913, each visit occupying about a week.

 

The observations were visual, photographic, and spectroscopic.

 

The visual observations were by naked eye and telescope.

 

The naked-eye observations were made for estimating the amount of scintillation at different altitudes, comparison of star regions, parts of the Milky Way, the Magellanic clouds, clusters, and nebulae. The telescopic observations included close double stars and detail of planetary surfaces. With the 6-in. doublet lens a series of photographs of rich star regions and nebulae was obtained.

 

The observation and delineation of solar prominences were also regularly carried out.

 

At the conclusion of our programme, I reported the result that in my opinion, taking into account all the circumstances, the site was decidedly suitable for an Astronomical Observatory of the highest order.

 

The question of proceeding with the establishment of a permanent Federal Observatory at this site is at present under consideration.

 

 

 

 

 

(2) GEODESY

 

(a) Trigonometrical Surveys of High Precision

 

 

Though many careful surveys have been effected in Australia, chiefly with a view to land settlement, trigonometrical surveys of high precision are, so far, confined to the three Eastern States. Of these only a brief description will now be given.

 

Queensland

 

The trigonometrical survey in this State extends approximately from 26° 30' to 29° 30' south latitude, and from 151° 15' to 153° 15' east longitude. It comprises 74 triangles and a base line of about 7 miles in length situated at Jondaryan. Its terminals are Mount Irving and Mount Maria, which are respectively 216 and 162 feet above the general level of the intervening ground.

 

The measurement of this base was made in 1884 by means of two steel tapes 100 feet long, about half-an-inch broad, and 0.01 inch thick.

 

These were compared with a standard bar of steel octagonal in section 1½ inches in diameter and 10 feet long, which was kept floating when in use in a trough of mercury, with thermometers plunged in it for obtaining the temperature of the bar. This bar was compared in 1883 with the New South Wales Standard Bar O.I.4, which gave its standardized length at 62° F. as 9.9998581 feet, which value was adopted throughout the operations of the trigonometrical survey.

 

In the base measurements the two tapes were placed " in wooden troughs and shaded by a board, a tension of 20 lbs. was applied by means of a spring balance, and five thermometers, whose index errors had been determined by comparison with a standard thermometer, were used along each 100 feet of tape. The troughs were supported upon pegs driven in the ground and set on even grade by means of a levelling instrument. Marks were made in copper discs inserted in the pegs at each hundred feet, the distance between the tape ends and the marks being measured by micrometer microscopes.

 

Ten sections, the six central ones averaging nearly 1 mile and the other two at each end being nearly half-a-mile mile long.

 

The terminal points of these sections were marked by stones sunk into the ground and set in concrete. Each stone had a metal plug, upon which a small mark was made denoting the terminal point of the section."

 

Three measurements were made with each tape, giving six independent values.

 

The two sets of three values made with each tape gave two mean results, which showed a difference of 0.117 inches.

 

Ten-inch theodolites (Everest pattern), by Troughton and Simms, provided with micrometer microscopes reading to one second of arc, were generally employed on the survey, and a 12-in. altazimuth was used at a few stations.

 

The angular measurements were obtained from two to eight readings made on each of eleven positions of the circle. The closing errors were within 1" for 29 triangles, from 1" to 2" for 29 other triangles, from 2" to 3" for 11 triangles, and upwards of 3" for the remaining 5 triangles. The greatest closing error was 3.90", and the average 0.95."

 

" The astronomical datum is the position of the station at Jimbour as determined by Captain Morris, R.E., and Lieut. Darwin, R.E., in 1882," while they occupied this station for the observation of the transit of Venus.

 

The longitude was determined by direct exchange of time signals with the Sydney Observatory by telegraph. In deducing from this datum the latitudes and longitudes of the trigonometrical stations, the elements used by Colonel James in the Ordnance Survey of Great Britain, in 1858, were adopted.

 

The azimuth datum was determined by astronomical observations made with a 20-in. transit instrument at Bloodwood, this being the apex of one of the triangles standing on the base line.

 

Astronomical observations for latitude and longitude were also made at several stations.

 

A comparison of the astronomical with the geodetic values for the four stations of Bloodwood, Brisbane, Haystack, and Mount Domville gives the following differences respectively. (40)

 

Latitude (geodetic - astronomical) -0.02"; +1.17''; +5.37"; -1.7".

Longitude (geodetic - astronomical) +6.57"; -0.05".

 

A minor triangulation of the City of Brisbane was carried out in 1890.

 

The principal triangulation was discontinued in 1891.

 

 

Victoria

 

The preliminary work of clearing mountain tops for a trigonometrical survey of the State of Victoria was commenced in 1853 under Captain Andrew Clark, R.E., after his appointment as Surveyor-General of Victoria, as already mentioned; but the primary triangulation was not actually commenced till seven years after.

 

In 1860 a base line was laid down on the Werribee Plains about 4.942 miles in length, which was subsequently extended by triangulation to a further length of 5.651 miles, making a total distance between the terminal points 10.593 miles.

 

"Each end of the measured base was defined by a solid mass of masonry built 5 feet into the ground, capped by a heavy stone with gun-metal plug and platinum centre, on which the terminal dot was marked. A heavy protection stone was placed over the cap stone, and this was surmounted by a timber pyramid, with pinnacle accurately centred over the platinum point." (41)

 

The measurement of this base was made by three iron bars 10 feet long and 1 inch square, with the ends turned round for about 4 inches in length, one end of each bar being finished quite flat and polished, and the other end being a segment of a sphere of 5-ft. radius, also polished. They were encased in wooden troughs 6 inches square, with hinged tops cut in three sections for the convenient examination of the three thermometers resting on each bar, the steel ends only being freely exposed 2½ inches out of the case.

 

The lengths of these bars were compared with due care "with a 10-ft. ordnance standard lent by the New South Wales Government " (40) and verified later by a similar standard obtained by the Government of Victoria from the Ordnance Survey Department of England.

 

In the actual measurement the bars were supported on pine trestles fitted with brass sockets on their top frames to receive a brass tripod. These frames carried a brass "camel", provided with the requisite fittings for bringing the ends of the bars accurately into juxtaposition. The three bars were placed in series with distances of about ¼ inch between the spherical end of one and the flat end of another, and the distance between the two was obtained by passing between them a graduated wedge of hard bell-metal 7 inches long and 2 inches broad, with faces inclined at angle of one-half a degree .

 

The difference of level between the terminal of the base being only 14 feet, and the intervening ground being fairly flat, the bars were adjusted by levelling into a horizontal position throughout the measurement.

 

A part of the southern portion of this base was re-measured to the extent of 2.11 miles, and the difference between the two results was found to be 0.308 inches, which was sufficiently small "to justify the assumption that by the original measurement the Werribee base was probably as accurate as any measured up to that time." (40)

 

The lengths of this base are as follow :-

 

(41) Measured base                                                     26091.82 feet

 

Extension by triangulation to Green Hill terminal           29839.83 feet

 

Total length                                                                55931.65 feet

 

The instruments used for angular observations were an 18-in. altazimuth, by Troughton and Simms, and a 13-in. theodolite, by Ertel, both being provided with micrometer microscopes by which the circles were read to 1"; two 12-in. theodolites read by micrometer microscopes to 4''' and 10" respectively; a 10-in. altazimuth and other theodolites of smaller size.

 

The triangulation was expanded in a decade throughout the extent of the Colony south of the 36th parallel of south latitude.

 

In this survey 209 stations of the first order, 267 of the second order, and a larger number of subsidiary points were connected and marked.

 

An average number of 170 observations were made at each of the primary stations to determine their positions. The triangulated area is about 70,000 square miles.

 

It was intended to measure a very suitable base of verification to the westward of Mount Gambler and Mount Schanck, in South Australia, these being the extreme western points connected with Victorian triangulation, but the work was not carried out.

 

A portion of the boundary line between the States of New South Wales and Victoria is a straight line running from a point near the source of the Murray River to Cape Howe on the east coast. The terminals of this line were agreed upon in 1870, and in order to determine their geographical co-ordinates with all possible accuracy, they were connected with the primary triangulation which was, for this purpose, extended to "The Pilot " and Mount Kosciusko, in New South Wales, these being the extreme eastern points of the survey.

 

The true azimuth of the line having been deduced by calculation from the co-ordinates of the terminal points, the line was ranged on the ground to the computed bearing and marked in 1872, starting from one marked terminal, and reaching the coast to within 17 inches of the other marked terminal.

 

The line was run by Messrs. A. C. Allen and A. Black, and the result is a fitting tribute to their skill, energy, and endurance in the accomplishment of an exceedingly difficult undertaking with such a remarkable success.

 

Colonel Clarke's elements of the figure of the earth were used in working out the results of the Victorian survey.

 

 

New South Wales

 

The territory of this State extends from the Murray River to the 29th parallel of south latitude, and from the eastern coast westward to the 141st meridian of east longitude.

 

About one-fourth of its whole area has been covered with a trigonometrical survey of high precision, which was initiated in 1867, carried on for a few years, suspended for some time, resumed in 1891, continued since over an extent of 43 million acres, and still progressing.

 

The base line of this survey, 5½ miles in length, is situated at Lake George, and a verification base of about 7 miles was laid down and measured at Richmond.

 

The survey comprises 119 stations of the first order, 583 of the second order, and 1,380 of the third order, all of which have been very substantially and permanently marked and connected, and whose geodetic co-ordinates are accurately known.

 

Some 490 additional stations have been piled and prepared for observation, of which 15 are to be ranked as first order, 75 second order, and 400 third order stations.

 

The stations of the first order constitute the primary skeleton of the survey, being a net of fundamental triangles whose sides range usually from 35 to 40 miles in length.

 

Astronomical observations for azimuth, latitude and longitude were made at many of these primary stations.

 

The second order stations are distributed at distances varying from 15 to 20 miles, this being the average length of the sides of the secondary triangles. These stations were connected by actual observations made upon them with smaller instruments than those used at primary stations, but with sufficient precision to meet all the practical requirements of a triangulation for the purpose of accurate mapping. No astronomical observations were made at these stations.

 

The sides of triangles connecting stations of the third order are from 7 to 10 miles. The positions of these stations were fixed by intersections based on observations made from surrounding stations of higher order, and their accuracy is sufficient for connecting all chain surveys on a uniform system.

 

The original base on Lake George was laid down and its measurement commenced in 1868, under the superintendence of Mr. G. R. Smalley, but it was abandoned before completion owing to an abnormal rise of the water of the lake, which covered parts of the line to a depth of 2 feet.

 

A new site for the base was selected in 1870 by Mr. P. F. Adams, the Surveyor-General at the time, under whose direction the measurement of its length was made twice by Mr. A. C. Betts.

 

The adopted standard of length was that of "Standard Bar O.I.4." referred to at p. 175 of Colonel Clarke's work on the comparison of standards published in 1866." (41)

 

This bar is of cast iron, 10 feet in length, the length being defined by microscopical dots marked near its ends. It is encased, and fitted with adequate support to prevent flexure, and provided with thermometers and micrometer microscopes for the observation of its marks. It was obtained many years before from the Board of Ordnance in England.

 

The actual measurement of the base was made with three 10-ft. bars of pine wood, encased and evenly supported, in wooden troughs 6 inches by 6 inches, and a little less than 10 feet in length, so as to allow a short portion of the ends of the bars to project outside. The ends were fitted with small brass plugs, upon each of which a terminal microscopic dot was marked, the distance between the terminal dots being the actual length of the bar. These lengths were standardized each morning and evening during the progress of the work by comparison with the Standard Bar O.I.4.

 

Each trough was supported on two "camels" provided with vertical, lateral, and longitudinal motion by means of which the three bars could be accurately placed in series along the line with the terminal dots of adjacent bars arranged in close pairs, always at the same distance, leaving a small constant amount of free space between the bars. This adjustment was made by means of a double microscope attached to the leading end of each trough. The microscope consisted of a single tube with two objectives at one end, rigidly mounted side by side, and two parallel webs, fixed on a diaphragm, at the upper end of the tube in the common focal plane of the objectives. By adequate means of adjustment the pair of dots could be brought in the fields of view and adjusted so as to bring each image into accurate bisection with each respective wire. The adjustment for parallelism of the optical axes and the distance between the webs having been previously ascertained, it was assumed that a constant distance between the adjacent bars was maintained throughout the measurement.

 

"The difference between the length of this base as found from the measurement and re-measurement was 0.542 inches in the total length of 5½ miles."

 

The verification base at Richmond was measured in 1879-80 by Mr. Conder twice.

 

The first measurement was made with the same three pine bars with which the Lake George base was measured, and in the second three 10-ft. rods of steel 3/8 of an inch in diameter were used. These rods were wrapped in blankets, and encased in wooden troughs with glass windows for inspection of the attached thermometers. The arrangement of terminal dots, the auxiliary apparatus for support, adjustment, and observations, and the methods employed in carrying out the work were in every respect similar for both sets of bars, and throughout the base operations at Lake George in 1870 and at Richmond in 1879-80. The length of both sets of bars was again standardized by daily comparison morning and evening with the same standard as adopted in 1870, namely, the Ordnance Bar O.I.4

 

The results of the two measurements were as follow :-

 

By pine bars                      36989.33651 feet

 

By steel rods                     36989.39166 feet

 

Difference                                0.05515 feet = 0.662 inches

 

"The combined error of measurement of the two bases and of the intervening triangulation produced an apparent discrepancy of only 12/3 inches in the length of the Lake George base. The bases were assumed to be correct, and an adjustment of the triangles was made in order to eliminate this small apparent difference." (40)

 

The instruments employed in astronomical observations and angular measurements were as follow :-

 

Two altazimuth instruments by Troughton and Simms, with object glasses of 3-in. aperture, provided with filar micrometer and delicate levels for latitude determinations by the Talcott method ; circles read by four micrometer microscopes to 1".

 

All observations, astronomical and geodetical, were made with these instruments at the primary stations.

 

Theodolite by Troughton and Simms, object glass 2½-in. aperture and 26 inches focal length, horizontal circle 10 inches in diameter read by two micrometer microscopes to 1", and two parts of a vertical circle 10 inches in diameter reading by vernier to 5".

 

Observations at second order stations, and all vertical angles for the determination of relative heights, were made with this instrument.

 

Recently a 10-in. Repsold theodolite, of the same pattern as that used in the trigonometrical survey of South Africa, was procured, and is intended to be employed in the future in place of the heavier 18-in. altazimuth.

 

The observed directions from a primary station to another station of the first and second order depended on twenty pointings made in reversed positions of the instrument.

 

The number of pointings was reduced to ten for second order stations, and to five for stations of the third order.

 

The great accuracy of these observations is shown by the following statement of the closing error of triangles.

 

In 171 triangles in which all angles have been observed with the large altazimuth the closing error is 0.70".

 

In 235 triangles, with two angles only observed with the larger, and one angle observed with the smaller instrument the average closing error is 1.15".

 

In 245 triangles, in which only one angle was observed with the 18" altazimuth, and the other two with the 10" theodolite, the closing error is 1.29".

 

In 173 triangles, with all the angles observed with the smaller instrument the closing error is 1.30".

 

The probable value of the average closing error of the triangles, computed according to General Ferrero's formula, for the primary triangulation of New South Wales is 0.54", which is less than the error similarly computed for the great trigonometrical surveys of Great Britain, India, and most of the other countries, and the closing error for triangles observed with the smaller instruments is, on the same criterion, reduced to 1.00".

 

Astronomical observations for latitudes were made at 74 stations with the 18" altazimuth by the Talcott method.

 

Azimuth was determined at 66 stations by meridian observations of circumpolar stars, made with the same instrument.

 

The longitude of 10 primary stations, and of 29 other important places in the State, were determined by the direct exchange of clock signals with the Sydney Observatory.

 

For the calculation of geodetic latitudes and longitudes, the co-ordinates of the Sydney Observatory adopted as the datum were : - Latitude 33° 51' 41.1" ;

Longitude 141° 12' 23.1".

 

The elements of the figure of the earth adopted in the calculations of the survey are those of a spheroid with - Major axis a = 20923134 feet ; polar = c = 20853429 feet.

 

Minor triangulations have been made around such important centres of the State as Sydney, Albury, and Newcastle, which were afterwards connected with the primary system.

 

Since the expansion of the geodetic survey of this State from the Lake George base in 1876, the principal observers in charge of the work were Messrs. W. J. Condor and J. Brooks. It was the former who set the high standard of accuracy which was worthily maintained by the latter.

 

Mr. T. F. Furber has been Director of the Survey for many years, and to him is due much of the credit of having planned means and methods by which this important undertaking has been brought to its present state of general efficiency and exemplary precision.

 

Mr. Furber, in his valuable paper (40) from which the information required for the above account was mainly drawn, mentions the names of P. F. Adams, late Surveyor-General, "to whom the very existence of the survey is in a large measure due," and the late H. C. Eussell, who, during the whole progress of the survey, aided in many ways where his scientific attainments were of the greatest service.

 

In May, 1912, a Conference was held in Melbourne at which the Director of Commonwealth Lands and Surveys, the Surveyor-General, and the Government Astronomer of New Zealand, and the Surveyors-General of the Australian States met to discuss, among other things, the question of a Geodetic Survey of Australia.

 

The following resolutions bearing on this matter were passed by the Conference :-

 

(41) "That, in the opinion of this Conference, it is desirable that a Geodetic Survey of Australia should be undertaken.

 

"That, in order to give effect to the foregoing resolution, this Conference respectfully recommends that such survey be undertaken by the Commonwealth Government, and submits in support thereof the following reasons :-

 

"(a) That the time has arrived when the Commonwealth should take its place in the scientific investigations of the world, not the least important of which are the determination of the figure of the earth, its density, and other cognate matters.

 

"(b) That work of this character, involving the highest form of survey should be effected under the supreme authority of Australia, as it is essential that it should be carried out with the greatest degree of accuracy on a uniform basis and a definite plan the individual parts being co-ordinated and eventually forming one homogeneous whole.

 

"(c) That the system which has hitherto prevailed by which the individual States carried out this work with instruments of varying character has resulted in divergent standards of accuracy, rendering the work to a great extent unsatisfactory, and, though much of it is of high grade, portions of it are impossible of reconciliation and co-ordination with a continental scheme.

 

"(d) That the desirableness of this work being undertaken by the Commonwealth Government is evidenced by the fact that the Geodetic Survey of the United States is carried out under the direct control of the Federal Government, and that the South African Geodetic Survey is also under one central control.

 

"(e) That such survey is absolutely necessary for the production of accurate maps, will be of high value in connexion with cadastral and geological surveys, and form a basis for topographical work for defence and other purposes. It will, moreover, provide a standard of accuracy for surveys of every description throughout the Commonwealth.

 

" (f) That it will afford an invaluable base to which settlement surveys already effected can be connected, providing data for re-establishing boundaries, which, with increasing density of settlement, becomes a matter of great importance. Further, as regards the sparsely occupied areas of Australia, such a survey, if carried out in advance of settlement, will be of the greatest utility and assistance in effecting the settlement surveys which can at any future time be reproduced with a minimum error and at a relatively low cost, preventing litigation consequent upon other methods."

 

It is earnestly to be hoped that the Commonwealth Government will sanction the recommendations of this Conference, and that the proposed undertaking may be carried out, so as to enable Australia to furnish in due course a contribution which should prove itself to be one of the greatest value and importance for the advancement of modern geodesy.

 

 

(b) Pendulum Observations.

 

 

Determinations of the gravitational value of "g" have been made in Australia at various times by different observers, since the early years of the nineteenth century, generally, by differential methods based on the swings of pendulums of the "invariable" type, and, in one case, by the actual measurement of a "second's pendulum " of the reversible or Bessell's type.

 

The earliest gravimetric observations made in Australia seem to be those of the French Expedition under Freycinet, who swung three pendulums at Sydney in 1819, and the latest are those of Dr. Wright, of Canada, which he made at Melbourne in April of this year (1913) on his return from Scott's Antarctic Expedition.

 

During this period of 95 years, the value of "g" has been determined at all the capitals of Australasia one or more times independently, forming a series of 24 results, 9 of which are for Sydney, 7 for Melbourne, 1 for Brisbane, 1 for Perth, 1 for Hobart, 4 for New Zealand, and 1 for Campbell Island.

 

The whole of this work has been discussed by the International Geodetic Association, and a summary of it, with brief descriptions of the observations made, apparatus employed, and estimated probable error of each result, is published in the Reports of the 13th, 14th, 15th, and 16th Conferenz der internalionalen Erdmessung.

 

There is satisfactory agreement of the values obtained by several observers at different times, that the gravitational constant "g" has been well ascertained for the Australian stations.

 

The values obtained are from Bericht uber die relativen Messungen der Schwerkraft mit Pendelapparaten in der Zeit von 1808 bis 1909 E. Borrass Verhandlungen 16ten allgemeinen Conferenz der internationalen Erdmessung.

 

"g" is the observed value reduced to the Potsdam system.

 

Writing φ the latitude, H the height in metres, θ the density of the local earth formation, g'-g the topographical reduction, then

 

go = g + 3086 X 10-7 H              the value reduced to sea-level.

 

3 θ

 

go = go +  ------------ (g - go) + g'-g value corrected for the protuberant earth,

 

4 X 5.52

 

 

 γo = 978.030 [1 + 0.005302 sin2 φ  - 0.000007 sin2 2φ ] the value

 

computed from Helmert's formula.

 

go = go = the gravitational anomaly.

 

I am indebted to the Government Astronomers and Surveyors-General of the Australian States for supplying me with accounts of the work of their respective departments; to Professor Ernest Scott and Mr. H. Wright for interesting historical notes on the astronomical work of early navigators; to Messrs. J. Tebbutt, C. J. Merfield, W. Gale, and H. Wright for information in regard to amateur astronomy; to Dr. J. M. Baldwin for arranging the results of pendulum observations; to Mr. J. A. Maroney for preparing the list of papers, and for giving valuable assistance in looking up authorities; and to some others who have helped me in various ways. To all of these I tender my sincere thanks.

 

 

 

 

 

LIST OF REFERENCES.

 

 

Corresponding to the numbers (1) to (41) as quoted in the Text.

 

(1) Australasian Association for the Advancement of Science. Vol. 8. Melbourne Meeting, 1900; Inaugural address by R. L. J. Ellery.

 

(2) Australasian Association for the Advancement of Science. Vol. 1. Sydney Meeting, 1888 : Section A. H. C. Russell - "Astronomical and Meteorological Workers in New South Wales, 1778 to 1860."

 

(3) Professor Ernest Scott, Life of Flinders.

 

(4) Catalogue of 7,385 stars prepared from observations made in the years 1822 to 1826 at the Observatory at Parramatta, New South Wales, founded by Lieut.-General Sir Thomas Macdougall Brisbane ; the Computations made, and the Catalogue constructed by Mr. William Richardson. (London. 1835.)

 

(5) Memoirs of the Royal Astronomical Society. Vol. 3.

 

(6) H. C. Russell. The Sydney Observatory : History and Progress. (Sydney. 1882.)

 

(7) Memoirs of the Royal Astronomical Society. Vol. 8, p. 251.

 

(8) J. G. Galle. Verzeichniss der Elemente der bisher berechneten Cometenbahen. (Leipzig. 1894.)

 

(9) Astronomical Observations made at the Sydney Observatory in the year 1859 by W. Scott, M.A. (Sydney. 1860.)

 

(10) John Tebbutt. On the Progress and present State of Astronomical Science in New South Wales. (From the Industrial Progress of New South Wales, 1870, p. 617.)

 

(11) Melbourne Observatory. Astronomical Results. Vol 1. (Melbourne. 1869.)

 

(12) Victoria. Sixth Report of the Board of Visitors to the Observatory. (Melbourne. 1870.)

 

(13) Observations of the Southern Nebulae made with the Great Melbourne Telescope from 1869 to 1885;. Part I. (Melbourne. 1885.)

 

(14) Royal Observatory Greenwich ; Photo-heliograph Results, 1874-1885. (Edinburgh. 1907.)

 

(15) South Australia. Report on the Post Office, Telegraph, and Observatory Departments, by Charles Todd, C.M.G., F.R.A.S., Adelaide, 1896, p. 194.

 

(16) Private Communication from H. B. Curlewis. Esq., Acting Government Astronomer of Western Australia.

 

(17) John Tebbutt. History and Description of Mr. Tebbutt's Observatory, Windsor, New South Wales. (Sydney. 1887.)

 

(18) John Tebbutt. Astronomical Memoirs (Sydney. 1908.)

 

(19) Monthly Notices of the Royal Astronomical Society. Vol. 25, p. 197.

 

(20) Astronomische Nachrichten. Vol. 64, p. 109.

 

(21) Observations of the Transit of Venus, 9th December, 1874, made at Stations in New South Wales. (H. C. Russell.) Sydney. 1892.)

 

(22) Monthly Notices of the Royal Astronomical Society. Vol. 44, p. 310.

 

(23) Monthly Notices of the Royal Astronomical Society. Vol. 20, p. 77.

 

(24) Monthly Notices of the Royal Astronomical Society. Vol. 27, p. 299.

 

(25) Astronomical and Meteorological Observations made at the Sydney Observatory in the year 1860 by W. Scott, M.A. (Sydney. 1861.)

 

(26) R. L. J, Ellery, C. Todd, and H. C. Russell. Report on the Telegraphic Determination of Australian Longitudes via Singapore, Banjoewangie, and Port Darwin. (Melbourne. 1886.)

 

(27) Victoria. Third Report of the Board of Visitors to the Observatory, with the Annual Report of the Government Astronomer. (Melbourne. 1863.)

 

(28) South Australia. Observatory and Telegraphs. Annual Report by Charles Todd, Esq. 1867. (Adelaide. 1868.)

 

(29) Journal and Proceedings of the Royal Society of New South Wales. Vol. 12, p. 225.

 

(30) Journal and Proceedings of the Royal Society of New South Wales. Vol. 14, p. 20.

 

(31) Astronomische Nachrichten, Nos. 2635-2636 (Dr. Auwers).

 

(32) Monthly Notices of the Royal Astronomical Society. Vol. 48.

 

(33) W. E. Cooke. Report on the Latitude and Longitude of the Perth Observatory. Western Australia. . (Official Report to the Under-Secretary. 21st September, 1899.)

 

(34) Monthly Notices of the Royal Astronomical Society. Vol. 62, p. 286.

 

(35) Australasian Association for the Advancement of Science. Vol. 14. Melbourne Meeting, 1913. Section A. P. Baracchi, Australian Longitudes.

 

(36) Australasian Association for the Advancement of Science. Vol. 6. Brisbane Meeting, 1895. Section A. P. Baracchi : On the most Probable Value and Error of Austral-asian Longitudes, including that of the Boundary Lines of South Australia with Victoria and New South Wales.

 

(37) Veroffentlichun dos Konigl. Preuszis-hcn Geodatischcn Institutes. Neue Folge, No. 15.

 

(38) Astronomische Nachrichten. No. 3993-94. Albrecht.

 

(39) Dr. Otto Klotz. Transpacific Longitudes between Canada and Australia and New Zealand executed during the years 1903- 1904. (Appendix 3. Report of the Chief Astronomer of Canada for 1905). (Ottawa. 1907.)

 

(40) Australasian Association for the Advancement of Science. Vol. 7. Sydney Meeting, 1898. Section A, p. 176. T. K. Furbor : The Trigonometrical Survey of New South Wales, with mention of Similar Surveys in other Colonies.

 

(41) Commonwealth of Australia. Department of Home Affairs. Conference of the Director of Commonwealth Lands and Surveys, the Surveyor-General and the Government Astronomer f)f New Zealand, and the Surveyors-General of the States of the Commonwealth of Australia. Melbourne, 20th to 25th May, 1912. (Melbourne. 1912.)