Some Historical Aspects of

Australian Capital Territory Mapping and its Map Grid

by Paul Wise and Kevin Wellspring, May 2015



Among the unique features of Canberra and the Australian Capital Territory (ACT), is that they have a common topographical mapping and cadastral grid. Now, as in the past, surveyors in the ACT can use the ACT coordinate system for any mapping or field surveying operations, without any corrections, knowing that the maximum error resulting from the work will be less than 1:100,000. Furthermore, conversion of coordinates on the ACT map grid to the national Map Grid of Australia (MGA), or its predecessor the Australian Map Grid (AMG), is no more complex than altering two of the conversion formulae’s parameters.

As with Canberra and the ACT, the ACT map grid evolved along with the development of the capital. This paper describes several historical aspects of this development.


In the beginning

The section of the 1875 map shown in Figure 1, clearly shows the towns of Yass, Goulburn and Queanbeyan; even Lake George is visible. But being before a national capital for Australia was envisaged the Australian Capital Territory is not shown.

Figure 1 : Section of an 1875 map showing the towns of Yass, Goulburn and Queanbeyan and Lake George.

About 10 years earlier than the date of this map, the trigonometric survey of New South Wales had commenced. The progress of the New South Wales trigonometric survey was reported, by the then Surveyor General Frederick Poate, to the 1912 Conference of Surveyors General. Poate stated that the trigonometrical survey now covered about a quarter of the State, but mainly in the south-east and was being extended west and north. As can be seen in the section of the map provided by Poate to the Conference, the completed work already covered the region for the new capital territory. Refer Figure 2. The hills of the now ACT which formed part of the New South Wales trigonometric survey were Ainslie, Coree, Tennent, Bimberi and Clear. Ainslie as part of that network initially became central to the initial surveys for the new capital territory.

Figure 2 : Section of the map provided by Surveyor General Frederick Poate, showing the progress of the New South Wales trigonometric survey as at 30 June 1912.

When Australia became a Commonwealth, one of the first seven Departments of State to be instituted was the Department of Home Affairs. Page 4 of Commonwealth Gazette No.1, of 1 January 1901, showed the Department of Home Affairs as having a servicing role under its Minister, William Lyne. After a series of Ministers the Department of Home Affairs was given to King O'Malley on 29 April 1910. Just over a year later, in May 1911, O’Malley launched the Federal Capital Design Competition. After entries were assessed by a Board, Walter Burley Griffin's design was announced as the winner on 23 May 1912. Refer Figure 3.

Figure 3 : The three assessors of the competition to select a plan for the Federal Capital (L-R) James A. Smith, Chairman John Montgomery Coane, John Kirkpatrick, with Conway Inglis Clark, Secretary of the Board on Camp Hill, Canberra, circa 1911 (courtesy Note the trigonometrical survey mark indicated by the braced striped pole in the centre of the photograph. Mt Ainslie is in the far background.

The Federal Capital Territory came into existence on 1 July 1911 under the Seat of Governments Acts of Surrender and Acceptance. Prior to that, in October 1909, the Prime Minister and the Premier of New South Wales had agreed on the area that would be ceded by the New South Wales Government to the Commonwealth. Following the acquisition of some 900 square miles (233,000 hectares), the site of the (Canberra) city was selected.

The next stage in establishing the capital city was the completion of a large number of necessary surveys, under the direction of the Commonwealth Director of Lands and Survey. Charles Robert Scrivener had been appointed to this position in 1910 and in September of that same year he signed a contour plan of the area between Mt Ainslie and Black Mountain in the north and Mugga and about where Scrivener Dam is today, in the south.

In association with the above surveys was the selection of Mount Stromlo, originally called Mt Strom, as the future site for an astronomical observatory. This site was chosen as it was situated symmetrically between the eastern and western boundaries of the new territory. A point on the summit would later be determined as the origin for all the surveys which were to be carried out within the territory. At that time, however, it was also the government’s desire to establish a primary meridian through this point. Strom would then not only be the initial meridian for surveys within the federal territory, but also ultimately for all surveys throughout Australia.

Although work had started on the necessary ACT surveys in March 1909, the geodetic, also called triangulation, survey was to provide the common framework to which the other surveys would all relate. By mid-1913, however, it appears that the only geodetic work was the establishment of trigonometric control in the region of the new capital city. This work included the establishment of the Ainslie-Kurrajong azimuth, which until the geodetic survey was complete in 1915, was the datum for any planning surveys and mapping. Scrivener stated in his annual report of 30 June 1913, some [geodetic] work has been carried out within the Federal Territory, the instrument used being an 8 inch Bamberg theodolite, not now rated very highly. Scrivener went on, saying continuity of the operations is a necessity in geodetic work, since surveyors who undertake it should have a better knowledge of mathematics than is necessary in ordinary survey work, and must be not only naturally adapted, but also specially trained, if the highest results are to be obtained. It is not every surveyor who will make a good observer when great precision is required, as in this case, and unless the work is well done it were better not to undertake it at all.

Thomas Alexander Vance was recruited as a surveyor, and by March 1914 was working in the Federal Territory on the geodetic survey, and the intensification of the Territory’s trigonometrical network. Vance’s work was to upgrade, as required, trigonometrical stations inside the ACT and read horizontal and vertical angles, during times of best visibility, mainly from the existing first order stations previously established by the New South Wales Lands department.

Figure 4 : 1914 photograph of Thomas Alexander Vance with his Repsold 10 inch theodolite.

Apart from three months, June to August 1914, Vance spent the period March 1914 to April 1915 on the geodetic survey using the department’s Repsold theodolite for the angular and astronomical observations. Any new beaconing by Vance’s party, was as described in Annex 7 to Department of Home Affairs, first annual report of the Lands and Surveys Branch, in 1913. The images shown in Figure 5 were extracted from that annex.


Figure 5 : Examples of primary and secondary survey beacons used in the ACT circa 1910. Note the beacon for secondary survey marks is the same design as that on Camp Hill in Figure 3.

Not all the surveys needed for the Territory could be conducted simultaneously, so were undertaken on the basis of priority and available resources. To further efficiently utilise available manpower, an arrangement with the Government of New South Wales saw the common boundaries, when determined by the Commonwealth Director of Lands and Surveys, accepted by both the Commonwealth and State.

The following lists the surveyors who also carried out work in the ACT in the early years some of which are in the photograph in Figure 6 :


Surveyors involved with ACT surveys 1909-1915

circa 1910

Charles Robert Scrivener


Percy Lempriere Sheaffe


Arthur Percival


M. Martin


RJ Rain


G. Marshall


JD Reid 

by June 1913

LJ Kelly

October 1913

Harry Mouat

March 1914

Thomas Alexander Vance

April 1915

Frederick Marshall Johnston


Figure 6 : Circa 1910 photograph with (L-R) : Felix Broinowski (Senior Draftsman), J. Morgan (Field Assistant), Arthur Percival (Surveyor), Charles Robert Scrivener (Chief Surveyor), W.G. Chapman (Clerk) and Percy Sheaffe (Surveyor).


The Australian Capital Territory and Canberra evolve

A feature of Burley Griffin’s design for Canberra, was a number of axes based on the significant hills of the region. Primarily, an approximate north-south axis ran between Ainslie and Kurrajong, the site of today’s Parliament House. At right angles to this axis were two parallel axes; one from Black Mountain running east and the second from Pleasant running west. Other lines and radials interconnected with these major axes.  


Minister King O’Malley, appointed a Departmental Board to oversee construction of the National Capital, based on the winning design. On 25 November 1912, the Board released its projected plan Design of the Lay Out of the Federal Capital City of Australia. Members of the Board as listed on the plan were Chairman David Miller, Percy T. Owen, Charles Robert Scrivener, George J. Oakeshott, J.S. Murdoch and Thomas Hill. The Board’s plan, however, reprojected Burley Griffin’s major axes to align with lines between the already established trigonometrical points.

The Board’s plan shows the major axis running between the trigonometrical points of Ainslie and Kurrajong. On the summit of Kurrajong was to be the Capitol building and below that, centred on the axis, was indicated to be the Houses of Parliament. The Houses of Parliament were to be sited on a small rise known as Camp Hill. The significance of this naming is well covered elsewhere. This rise must have been significant as on its height it had a second order trigonometrical station. Refer Figures 3 and 5 above. On early plans Camp Hill is called Camphill and later Canberra Hill. As these two names fell into disuse, this paper will use Camp Hill unless the discussion specifically requires the other name(s).

Despite the fact that a number of the surveys for the new capital were well underway or completed, and some of the required infrastructure sites had already been pegged out by the surveyors, it appears that Minister O’Malley wanted what is termed today as a politician’s photo op with him being front and centre. While no doubt of great importance to the future capital’s residents, the pegging of the site for the power station let alone the night soil site must not have seemed conducive for such an occasion.


Figures 7 and 8 : Photographs taken, looking approximately south, during the function on 20 February 1913 at which King O’Malley drove the first peg of the city survey on Canberra Hill (Camp Hill). Surveyor Percy L Sheaffe is pictured far right with his theodolite in Figure 7. The trigonometrical survey station marker for Camp Hill is at the far left in Figure 7. In Figure 8, both Sheaffe and his theodolite and the Canberra Hill trigonometrical survey station marker are clearly visible.

With the ceremony for the official laying of the Foundation Stones of Canberra looming, some three weeks prior on 20 February 1913, O’Malley was photographed driving the so-called first peg of the City survey. Refer Figures 7 and 8. With the Camp Hill trigonometrical marker and peg being in the photographs, they must have been taken looking approximately south towards Mugga; Kurrajong would have been off to the right. Note that the trigonometrical marker is the same as in Figure 3.

Mr Surveyor Percy Sheaffe is also pictured in Figures 7 and 8, with his theodolite as it was his duty on the day to precisely locate the peg. As his fieldbook shows, the peg was positioned 20.90 links (a link is about 20 centimetres) or 4.2 metres due west of the Canberra Hill/Camp Hill trigonometrical point. Refer Figure 9. From Sheaffe’s fieldbook it can also be seen that the peg was on the Kurrajong – Ainslie axis, conforming to the Departmental Board’s plan. Furthermore, the peg indicated the location of the centre of the then proposed Houses of Parliament. Like turning the first sod, marking the location of the future Houses of Parliament of Australia would have seemed a most notable occasion. Unfortunately, O’Malley’s peg was to be lost for the next 100 years.

Figure 9 : The page from Surveyor Percy Sheaffe’s fieldbook showing his determination of where the peg was to be placed.

Suffice it to say that Burley Griffin was not thrilled with the Board’s adaptations of his design and lobbied hard for his engagement to personally oversee the capital’s construction. He was successful and thus appointed Federal Capital Director of Design and Construction in October 1913; the Departmental Board was disbanded.

It would seem that Burley Griffin redesigned the axes and for the next 3 to 4 years Scrivener’s surveyors laid them out. The plan titled Main Axial Lines, Canberra, Federal Capital City was signed by Surveyor Harry Mouat on 31 March 1917. The main axis Ainslie – Kurrajong was now offset from the trigonometrical stations to the west. The terminals of the axes were marked by concrete blocks and have survey connections to the trigonometrical stations where applicable. In addition, during the survey depicted on Mouat’s plan, substantial concrete blocks were set on line at approximately 1000 foot (300 metre) intervals and then accurate measurements taken. The plan shows 110 such blocks were emplaced along with 10 points consisting of GI (Galvanised Iron) pipe as well as using numerous wooden posts.

Another major change on Mouat’s plan was that Mount Strom, now Stromlo, trigonometrical station had now become the origin of the coordinates and trigonometrical meridian. As far back as 1910 O’Malley was…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. With the geodetic survey now completed some years before Mouat completed his plan, O’Malley’s desire, at least for the primary meridian for the ACT, had eventuated.

With the Burley Griffin change of axes, O’Malley’s peg was no longer at the centre of the proposed Houses of Parliament. Furthermore, when the site was finally selected for the Houses of Parliament which were opened in 1926, now Old Parliament House, the site chosen was closer to the lake. O’Malley’s peg now no longer signified anything other than a moment in history!


Towards a Common Topographical Mapping and Cadastral Grid

Harry Mouat’s plan of the axes now became the foundation for the future Canberra. Its significance is underlined by the fact that a copy of this plan used to hang on the wall of the old wooden shed in which the Survey Section of the then Department of the Interior was accommodated in 1952. These buildings were the home for the then Department, and were situated on the north side of Lennox Crossing. Lennox Crossing was subsequently submerged when Lake Burley Griffin was created around mid-1964. From 1947, the National Mapping Section which was part of the Property and Survey Branch, Department of the Interior was also accommodated on this site. Today this area is known as the Acton Peninsula and is the site of the National Museum of Australia.

When the Department of the Interior was moved into more permanent accommodation in the North and South Buildings in Civic Square, the copy of Mouat’s plan was also relocated. These buildings still exist today, housing the ACT Local Government Legislative Assembly and providing offices for its members. A copy of the plan obtained from the National Library of Australia, MAP G8984.C3B3 1917, can be viewed here. As Electronic Distance Measuring (EDM) equipment, for example Geodimeter and Tellurometer, became available various axes were remeasured. Anecdotal evidence suggests that their accuracy was proved to be better than 1:50,000 or 20 centimetres per kilometre.

Initially the relatively small area of the early capital allowed coordinates for survey points to be calculated using plane geometry with the origin at Stromlo. The small areal dimensions meant that earth curvature did not have to be taken into account. As Canberra grew, however, and the satellite towns of Woden, Weston Creek and Belconnen were established, various extensions were made to the early axial control. While Stromlo was retained as origin and trigonometrical meridian, survey coordinates now had to be calculated using Clarke's 1858 figure of the earth, or spheroid, and mapped using the Cassini-Soldner map projection.

The Cassini-Soldner map projection is the ellipsoidal version of the Cassini projection for the sphere. Cesar Francois Cassini de Thury (1714-1784) developed his spherical version for topographic mapping of France in the middle 18th century. The properties of the Cassini-Soldner map projection are that it has a straight central meridian along which the scale is true. All other meridians and parallels are curved, and the scale distortion increases rapidly with increasing distance from the central meridian. It is therefore most suited to long, narrow areas such as the ACT. After the development of the spherical Transverse Mercator map projection in about 1772 it was further developed on the spheroid by Carl Friedrich Gauss and Johann Heinrich Louis Kruger. The Gauss-Kruger Transverse Mercator later replaced the Cassini-Soldner map projection in many countries including Australia and the ACT around 1966.

The Government’s intention to develop the National Capital, was announced by Prime Minister Robert Menzies in 1960. The then Survey Section of the Department of the Interior began serious work on extending the control network. At that time this network only consisted of the permanent marks along the radial lines. As the management team could foresee that, under the guidance of the then National Capital Development Commission (NCDC), Canberra was to expand and include a number of satellite cities, a comprehensive geodetic survey was undertaken to cover all likely areas of development. This survey consisted of both triangulation and trilateration, with several astronomic azimuth observations. Two Laplace stations were provided by the Division of National Mapping to correct azimuth as the network approached a gravity anomaly near Orroral trigonometrical station.

The accuracy of this survey was claimed to be 1:300,000 by the Survey Section but this was an absolute accuracy. The Division of National Mapping, which had responsibility for geodetic surveys in Australia, applied the statistical technique for assessing the accuracy of first order networks to the survey and recorded the accuracy as 1:1,000,000.

In this historical setting we have the fundamentals of what followed when the Australian National Spheroid (ANS), the Australian Geodetic Datum (AGD) and the Australian Map Grid (AMG) were introduced after agreement by the members of the National Mapping Council in resolutions 292 and 294 around 1966.


The ACT Control Network

Prior to the adoption of the Australian National Spheroid (ANS), Clarke’s 1858 spheroid had been in use for calculating survey coordinates. A move internationally to adopt the Transverse Mercator (TM) map projection, and ultimately the Universal Transverse Mercator (UTM) map projection, meant a move away from the Cassini-Soldner map projection for the ACT, as described above. This change, however, suddenly impacted some 1000 Deposited Plans already lodged in the Office of the Registrar of Titles in the ACT. Adopting these parameters required amendments to all these plans to vary the bearings of all cadastral boundaries and noting the change of datum. Some lateral thinking, however, negated this huge task.

Lindsay Lavers, a field Surveyor came up with the brilliant idea which was subsequently adopted by mutual agreement between the National Mapping Council and Australian Survey Office. A mapping plane, 2000 feet or later 610 metres, above mean sea level was selected. The height of this plane being at the average height of the ACT above mean sea level. Because of the small area of the ACT, these parameters allowed the continued use of plane trigonometry for coordinate calculations within the ACT. It also avoided the necessity of making height corrections for everyday measurements. For geodetic calculations this saw the adoption of a modified spheroid for the ACT by simply adding 2000 feet or 610 metres to the a radius, or equatorial axis, of the adopted spheroid. The b radius, or polar axis, and flattening were not modified. Thus calculations could be performed on a plane 2000 feet above mean sea level as though it were at mean sea level. The same datum was thus retained for topographical mapping and cadastral surveying. This was an extremely useful asset when the National Capital Development Commission (NCDC) began their planning on the Survey Office’s maps and for the subsequent translation of the NCDC’s plans to actual cadastral boundaries on the ground.


The Australian National Spheroid (ANS), Australian Geodetic Datum (AGD) and Australian Map Grid (AMG)

In 1966 when these three national mapping parameters were introduced, the Australian Survey Office (ASO) was requested to bring its mapping onto the Australian Map Grid (AMG). As this would have meant separating the topographical mapping from the cadastral mapping, ASO requested an exemption. At that time the ASO had established a planning series of maps at a scale of 1:10,000 and another at 1:500 scale. These two map series, using the then Transverse Mercator local projection, were used by the NCDC and the ASO for the design, computation and set out of the city of Canberra as it developed.

From the ASO’s point of view it was also not practical to convert these mapping series to AMG, because the ACT was in the overlap of zones 55 and 56 of the Universal Transverse Mercator. Two coordinate sets would have been required, a set for each zone. It would also have meant that these coordinates would have had to have been published with sea level values. Further, the scale factor of the TM projection in the overlap area of zones changes rapidly, at about 1:2,500. Every distance set out by the cadastral surveyors would therefore have required calculation to allow for these factors. One last complication was that the grid bearing of every cadastral boundary line would be different in the two zones. The solution was to have a modified Australian Map Grid for the ACT.

This modified map grid used the AGD coordinates of Stromlo trigonometrical station as the true origin to project the ACT spheroid using the Universal Transverse Mercator projection formulae. Again over the very small area of the ACT this ruse leads to negligible errors. At the east-west extents of the ACT, it was possible that the effect of earth curvature and map scale could have become a problem at the extremes of longitude for some of the more accurate engineering surveys. A central scale factor of 1.000086 thus combined a 610 metre plane height projection factor of 1.000096 and a 1:100,000 scale correction to minimise distortion away from the central meridian. For most practical purposes, the measured ground distances could be directly compared with plane coordinate distances. False origin values of E200,000 metres and N500,000 metres at Mount Stromlo avoided negative coordinate values.

With the introduction of metric coordinates the old imperial measurements were modernised. Details of some of this work are given in Kevin Wellspring’s 1973 paper Some Aspects of the Conversion from Imperial to Metric Co-Ordinates in the Australian Capital Territory, which is available via this link. ACT metric coordinates are known as ACT Standard Grid Coordinates (SCG). They are based on a single zone Transverse Mercator projection of the Australian National Spheroid, with the Central Meridian being that of the Stromlo Trigonometrical Station as fixed by the 1966 National Adjustment (Longitude E 149° 00' 33".4614).

These modifications retained the approach of having a common topographical mapping and cadastral grid. It especially allowed the use of plane trigonometry for all calculations within the grid thus minimizing the chance of errors, particularly when computations were carried out in the field.

The problem of providing AMG coordinates to National Mapping was also very simply solved using this projection. Firstly, all of the software developed for the AMG was immediately useable with only minor modifications for the constant parameters of the a or equatorial radius of the spheroid, the central scale factor and the true origin for the area. To convert ACT coordinates to AMG coordinates required only the conversion of the ACT Transverse Mercator coordinates to latitude and longitude on the ACT spheroid using the existing AMG software with the modified parameters. Then that latitude and longitude was essentially the same on the ANS and so could be reprojected as AMG coordinates.

Naturally this projection remains accurate only over a very small area such as the ACT. Also the underlying assumption of the surface of the ANS and ACT spheroids being parallel and the latitude and longitude being the same for a common point on both spheroids, limits its area of use.

The 1913 topographic map at a scale of 3 inches to 40 chains (1:11,000 approx) of the City Site and Federal Territory environs can be viewed here and the later 1953 National Mapping, R501 series, topographic map at a scale of 1 inch to 4 miles (1:250,000 approx) of the Australian Capital Territory can be viewed here.


ACT Precision Zone

In 1972, a combined effort of the Survey Branch of the then Department of Services and Property and the Division of National Mapping resulted in the establishment of the ACT Precision Zone of survey control. This zone extended from the Hume Highway in the north and from Captains Flat in the east, to the southern and western borders of the ACT. This survey provided the primary control for all new development areas in the ACT since 1972.

The establishment of the precision zone is considered a very significant event which has had a profound effect on surveying nationally and probably internationally. The zone came about as the Stromlo and Taylor trigonometrical stations were first order stations in both the national network and the ACT network. When the AGD coordinates of these two stations were published, ASO saw that the calculated distance between these two stations differed from that measured, by some 15 inches in a distance of approximately 5 miles. While this accuracy was acceptable nationally it was significant locally. Both organisations had sound reasons not to compromise but a solution had to be found. It is understood that Natmap’s Tony Bomford came up with the idea of a precision zone within the AGD to accommodate the ACT.

This zone was achieved by including all first order ACT stations within the national first order network and readjusting a portion of that network using the Varycoord adjustment program, but holding all ACT stations fixed. Naturally the ACT origin, Stromlo trigonometrical station, was to be held to the AGD values. The New South Wales and Victorian Lands Departments were consulted concerning their requirements for fixed points in this area. Outside the Precision Zone a buffer zone was declared which would absorb any differences which the new survey might disclose. A preliminary adjustment revealed problems to the west of the ACT. Since New South Wales was committed to hold values for an area one figure (a figure consisted of two or more triangles of the network with a common, approximately east-west oriented side) west of the ACT, a compromise was arranged. The ACT agreed to let Coree float and New South Wales agreed to extend the buffer zone one more figure west hence distributing the differences and arriving at a satisfactory adjustment.

Now within the ACT Precision Zone the AGD network and ACT network were identical. From a national perspective a homogeneous set of coordinates was available, yet within the ACT, street-level surveys could continue to be easily integrated. A short but more detailed history is available via this link.


A Return to Camp Hill Trigonometrical Station and O’Malley’s Peg

Initially the circa 1930s photograph at Figure 10 only showed an aerial view of now Old Parliament House, under construction, with Camp Hill towards the lower right. A higher resolution scan (part inset) revealed that the Camp Hill trigonometrical marker was still there and furthermore the tree to the right is the same as in the background of the 1913 photographs at Figures 7 and 8; just a bit bigger after some 15 or more years of growth.

Figure 10 : Circa 1930 aerial view of now Old Parliament House with Camp Hill towards the lower right. The insert from a higher resolution scan shows the Camp Hill trigonometrical marker and the tree to the right is the same as in the background of the 1913 photographs at Figures 6 and 7. The viewing platform and flagpole were probably added to allow visitors to overview the construction of the Houses of Parliament.

While the photograph appears to confirm that the now Old Parliament House was built on Mouat’s axis could modern graphics quantify the relativity of the axes and locations? In 2013, the Young Professionals of the Surveying and Spatial Sciences Institute (SSSI) used modern technology to re-establish the location of O’Malley’s peg and this information put the early surveys into a modern reference frame. Between 1917 and 1988, when today’s Parliament House was opened however, the Kurrajong and Camp Hill areas on the axis to Ainslie were effected by earthworks associated with landscaping and construction. Refer Figure 11. The rise then known as Camp Hill in 1913 was removed in 1986 to create today’s direct line of sight along the Ainslie axis. Ground level where O’Malley drove the peg in 1913 is today some 3 meters lower.  


Figure 11 : Profile along the centre line between today’s Parliament House and Lake Burley Griffin showing the original and landscaped topography. Of note is the removal of the rise known as Camp Hill in 1986.

To visually show the difference between the axes as proposed in the 25 November 1912 projected plan Design of the Lay Out of the Federal Capital City of Australia and the 31 March 1917 plan Main Axial Lines, Canberra, Federal Capital City the first was projected in red and combined with the latter in blue. Figure 12 refers. The locations of Kurrajong and Camp Hill trigonometrical points, Mouat’s concrete blocks 1 and 2 and O’Malley’s peg were highlighted and the current site of now Old Parliament House superimposed.

In Figure 12, it is now clear that with the adoption of the axes as shown by Mouat in 1917, O’Malley’s peg had lost any significance by now not marking the axis and after 1926 having no relationship with the location of the then Houses of Parliament.

Figure 12 : Section of the 25 November 1912 projected plan Design of the Lay Out of the Federal Capital City of Australia (in red) combined with 31 March 1917 plan Main Axial Lines, Canberra, Federal Capital City (in blue) with the locations of Kurrajong and Camp Hill trigonometrical points, Mouat’s concrete blocks 1 and 2 and O’Malley’s peg identified. The current site of now Old Parliament House has been superimposed.








Distance –original &






35° 51’ 32”

Not shown

Sheaffe’s fieldbook




35° 51’ 28.8”

Not shown

Modern coordinates


Camp Hill


36° 13’ 39”



From coordinates

Concrete Block 1



69° 26’ 30”



Mouat’s plan

Concrete Block 1

Concrete Block 2


36° 09’ 00”



Mouat’s plan

Concrete Block 1

Concrete Block 2


36° 08’ 57.8”



Modern coordinates

Camp Hill

O’Malley's peg


270° 00’ 00”




Sheaffe’s fieldbook

Camp Hill

Concrete Block 2



266° 13’ 34”

35.379m 116.07bft


From coordinates















Concrete Block 1


249° 26’ 30”


Mouat’s plan

Known coordinates (E,N)

Calculated coordinates (E,N)












Modern coordinates








Parliament House Flag





ACT Government website







Coincident with Mouat’s plan

Note : Mouat used British “feet” (bft) which are converted to meters (m) using the factor 0.30479947


Figure 13 : Diagrammatic and survey relationship between points on Kurrajong and Camp Hill.


Figure 13 shows Camp Hill trigonometrical point was 529.735 metres north-east of Kurrajong trigonometrical station and O’Malley’s peg was placed 4.2 meters due west of Camp Hill. The 1917 axis defined by emplaced Concrete Blocks 1 and 2 is some 48 meters south-west of Kurrajong and 36 metres west of Camp Hill, a shift away from the 1912 axis of nearly 40 metres.

To confirm that today’s axis follows the 1917 plan, the modern coordinates for Mouat’s Concrete Block 1 were calculated and found to correspond with those of the flag pole on today’s Parliament House and the azimuth of this axis is practically the same.

Figure 14 is a section of the 1:25,000 scale orthophotomap with the relative locations of Kurrajong and Camp Hill trigonometrical points, Mouat’s concrete blocks 1 and 2 and O’Malley’s peg, positioned in today’s landscape. If the proposal to monument the location of O’Malley’s peg proceeds at some future time perhaps the distance and direction to the two associated survey marks should also be indicated as their role was no less important. 


Figure 14 : Section of the 1:25,000 scale orthophotomap showing the relative locations of Kurrajong and Camp Hill trigonometrical points, Mouat’s concrete blocks 1 and 2 and O’Malley’s peg in today’s landscape.




Thanks to Frank Blanchfield for the information on O’Malley’s Peg as determined by Ed Dark and the Young Professionals of the Surveying and Spatial Sciences Institute (SSSI). This information provided the modern reference frame for positioning the historical points in relation to the axial on Mouat’s plan. Alex Petrow’s provision of information associated with the ACT Precision Zone is also acknowledged.



Australian Survey Office (1977), The Cadastre of the ACT - Section 04 - ACT Control Surveys, unpublished internal document.

Beaver. P. W. (1953A), The History of Surveying in N.S.W., The Australian Surveyor, Vol.14, No.6.

Beaver. P. W. (1953B), The Early Detail Surveys of Sydney, The Australian Surveyor, Vol.14, No.8.

Commonwealth Year Book (1911), Australian Bureau of Statistics, 1901-1910 Year Book Australia, cat. no. 1301.0, ABS, Canberra, accessed at :

Conference of Surveyors General (1912), Conference of the Director of Commonwealth Lands and Surveys, the Surveyor-General and the Government Astronomer of New Zealand, and the Surveyors-General of the States of the Commonwealth of Australia : Melbourne, 20th to 25th May, 1912, Melbourne, Albert J. Mullett, Acting Government Printer, C.6832.

Department of Home Affairs (1913), Annual Report of the Lands and Surveys Branch, under Director Charles Robert Scrivener, for year ending 30 June 1913, Government Printer Sydney.

Kennedy William D. (1973), Origin of the ACT Land Surveying System, 16th Australian Survey Congress Technical Papers, pp.I1-I5, Canberra, 1973.

McLean, J.B. (1967), A Short History of the Trigonometrical Survey of New South Wales, The Australian Surveyor, Vol.21, No.6, pp.135-143.

Wellspring, Kevin H. (1973), Some Aspects of the Conversion from Imperial to Metric Co-ordinates in the Australian Capital Territory, 16th Australian Survey Congress Technical Papers, pp. D1-D4, Canberra, 1973.