Prior to 1966, Australian maps used a transverse mercator projection, in yards, with the Clarke 1858 ellipsoid. This was called the Australian National Grid (ANG).
Common map series in this projection were the 1:250,000 miles maps and the 1:63,360 inch to the mile maps. These maps were surveyed by the Royal Australian Survey Corps. Part of a 1:250,000 miles map can be seen here.
The parameters for ANG are as follows:
Central scale factor : 1.0 exactly False Easting : 400 000 yards False Northing : 4 915 813.467 yards (Add 1 000 000 for Tasmania) Zone Width : 5 degrees Initial Central meridian : 116 degrees East longitude.
By comparing three points (Tangy Dangy, Avoca, and Mangrove trigs*) on the Gosford & Norahville 1:63,360 inch-to-the-mile map with the same locations on the modern (GDA94) maps, and then computing the shift params using the tool built into AusDatumTool, I came up with the following MapInfo coordinate system string which gives an accuracy of about +/- 80 metres in this area:
"ANG (Zone 8, 3 param)", 8, 999, 36, 79.723, 7.352, 24.203, 4, 151, 0, 1.0, 400000, 4915813.467
The params in the first coordinate string are:
Projection = 8 (Transverse Mercator) Ellipsoid = 36 (Clarke 1858: a=6378293.639, b=6356617.982, 1/f=294.260680) dX = 79.723 dY = 7.352 dZ = 24.203 Units = 4 (yards) Origin of Longitude = 151 Origin of Latitude = 0 Scale factor = 1.0 False easting = 400000 False northing = 4915813.467
Using the SEVENPAR program I computed the following MapInfo coordinate system string which is accurate to around +/- 60 metres in this area (You could also use our free Compute Datum Shift tool):
"ANG (Zone 8, 7 param)", 8, 9999, 36, 9940, -5396, 7101, -131.8, 63.9, -95, 2084.7, 151, 4, 151, 0, 1.0, 400000, 4915813.467
The params here are:
dX = 9940 dY = -5396 dZ = 7101 rX = -131.8 rY = 63.9 rZ = -95 M = 2084.7
* Test points determined from Gosford & Norahville 1:63,360 map (1942) and modern Gosford, Wyong GDA94 maps:
| Location | ANG coordinates | GDA94 coordinates | Conversion error, 3 params | Conversion error, 7 params | params
| Wyrrabalong Trig | 448429 yE, 871857 yN | 358275 mE, 6302775 mN | errX=-35m, errY=+30m | errX=-18m, errY=-1m |
| Avoca Trig | 441000 yE, 866321 yN | 351563 mE, 6297600 mN | errX=-17m, errY=+14m | errX=-17m, errY=-22m |
| Niagara Park Railway Station | 436107 yE, 874500 yN | 346938 mE, 6305013 mN | errX=-8m, errY=-8m | errX=-12m, errY=-25m |
| Wyong Trig | 442893 yE, 887571 yN | 352913 mE, 6317050 mN | errX=-9m, errY=+22m | errX=+9m, errY=+25m |
| Tumbi Trig | 443893 yE, 874607 yN | 354013 mE, 6305213 mN | errX=+32m, errY=+26m | errX=+43m, errY=+4m |
| Lyre Trig | 430536 yE, 866286 yN | 341900 mE, 6297350 mN | errX=+82m, errY=+48m | errX=+61m, errY=+20m |
| Sterland Trig | 431750 yE, 885429 yN | 342775 mE, 6314875 mN | errX=-20m, errY=+44m | errX=-24m, errY=+51m |
| Tangy Dangy Trig | 441286 yE, 882786 yN | 351525 mE, 6312675 mN | errX=-6m, errY=-5m | errX=+6m, errY=-10m |
| Mangrove Trig | 429714 yE, 877357 yN | 341013 mE, 6307513 mN | errX=+23m, errY=-9m | errX=+8m, errY=-15m |
| Avg errX=26m, avg errY=23m | Avg errX=22m, avg errY=19m |
| Location | ANG coordinates | AGD66 coordinates | Conversion error, 3 params |
| Starkey Trig | 404250 yE, 870357 yN | 317775 mE, 6300450 mN | errX=-9m, errY=+2m |
| Croft Trig | 411393 yE, 879107 yN | 324150 mE, 6308575 mN | errX=-8m, errY=+2m |
| Haycock Trig | 411893 yE, 865964 yN | 324813 mE, 6296575 mN | errX=+17m, errY=-4m |
| Avg errX=11m, avg errY=3m |
DX = 234.61 DY = 56.599 DZ = -145.234
There's also a book on this topic called "Australia in Maps: Great Maps in Australia's History from the National Library's Collection".
