PROCEEDINGS OF SECTION E. 553"- 



with data of the railway survey ; the resulting longitude, 140° 45' 32", 

 is only a few yards less than that calculated by geodetic survey from 

 Melbourne Observatory, kindly supplied for this paper by the Surveyor- 

 General of Victoria. Mr. J. M. Reed. 



Part II. — Latitude. 



The first South Australian latitudes by Matthew Flinders, E.N.,. 

 in 1802, are in every case correct to the nearest minute. 



The next reliable latitudes since that date were observed in 1842 

 by Colonel Frome, Surveyor-General, with a sextant, during short 

 exploratory trips south and north of Adelaide. 



Afterwards by Mr. G. W. Goyder, when Assistant Surveyor- 

 General to Major Sir Arthur Freeling, 1857-61. Mr. Goyders deter- 

 mination of the latitude of Black Rock in the north— 32^ 44' 29"— is 

 accepted as correct, that of Mount Brown as being 6secs. too low, and 

 Mount Margaret lOsecs. too high. 



Since then many excellent determinations have been made by 

 various officers of the Survey staff, of which the following are the best : — 

 During 1879 one of the staff was entrusted with the duty of defining 

 the north boundary of county MacDonnell, which, by proclamation in 

 the Govermnent Gazette, commenced in latitude 36° 28' 00". His 

 observations were so carefully made that the point fixed by him agrees 

 to a second with the position calculated by recent surveys connected 

 with Adelaide Observatory. This determination was checked seven 

 years later by another officer's observations, made 32 miles north and 

 connected by chainage. They agree to one-third of a second. 



In connection with the trigonometrical survey north of Lake 

 Gairdner careful determinations of the latitude of three stations were 

 made by Mr. W. Barron, with a transit theodolite and sextant, which 

 do not differ from their calculated values more than 3secs. The middle 

 one of these, Kingoonya, latitude 30° 57' 49", has been adopted as 

 exact. Mr. Barron's observation at the 348th milepost on the New 

 South Wales boundary line, latitude 28° 57' 57"-5, is equally good, 

 and agrees exactly with the intersection of the 29th parallel subse- 

 quently defined by Mr. Cameron, under contract with the New South 

 Wales and Queensland Governments. 



A more recent determination at the 134th milepost (latitude 32° 

 04' 23"), connected by chainage with boundary post east of Pinery 

 Hill, gives for the post, latitude 32° 12' 32". Thence, by calculation 

 westward to Black Rock, close agreement is obtained with the latitude 

 observed there, making Black Rock latitude 3secs. higher. 



Going northward from Black Rock the latitude of Mount Serle is 

 calculated to be 30° 30' 15". There the local observation, is quite 

 wrong ; but calculating southward from the 26th parallel the value 

 of 30° 30' 12" is obtained. The latter of these carried westv/ard to 



