PROCEEDINGS OF SECTION E. 549 



lunar observations (1) were considered so good that tliey were printed 

 in pamphlet form as a typical example of this kind of work ; but, 

 unfortunately, the result was nearly two miles in error. The triangu- 

 lation result was really the best, being within half a mile. 



Further chronometric determinations to fix the boundary were 

 also made by Captain Stanley, R.N., of 11. M.S. Britomart, and by Cap- 

 tain Stokes, K.N., of H.M.S. Beagle, 1845, both ot whom favored a 

 point at some distance west of that indicated by Mr. Tyers' observa- 

 tions ; so the question of deciding upon a starting point was ultimately 

 referred to a select committee. (See British Parliamentary Papers, 

 No. 120, vol. 29, printed March 9tli, 1841 ; also Inquiry of 1855, Votes 

 and Proceedings, New South Wales, vol. 2.) 



SNAPPER POINT, PORT ADELAIDE; SEMAPHORE AND GLENELG. 



Early in the history of the colony signal stations were erected at 

 West Terrace, Port Adelaide, Glenelg, the Semaphore, and at the 

 lightship, for the purpose of announcing the arrival and departure of 

 vessels, as mentioned in the second report of the Colonisation Com- 

 missioners, 1840-41. 



In 1844 the Glenelg signal station was chosen by Colonel Frome 

 as the western extremity of the base line of an extensive trigonometrical 

 survey, and its geographical position was consequently of great im- 

 portance. 



The longitude was ascertained, as far as practicable, by chrono- 

 metric measurements by Admiral Crozier, 1839 ; Captain Stokos, K.N., 

 1842-5 ; Captain Wickham, Captain Hutchison, and more recently 

 by Captains Flo ward and Goalen. A letter to The Times, from Mr. 

 John Arrowsmith (reprinted in the South Australian Register of Septem- 

 ber, 18th, 1841), also gave valuable information on Australian longitudes. 



Captain Inghs, Harbormaster, Port Adelaide, has, by courtesy of 

 the President of the Marine Board, kindly supplied notes to the follow- 

 ing effect : — '" According to old charts Snapper Point and Glenelg flag- 

 staff were in exactly the same meridan. Captain Hutchison considered 

 the latter to be in longitude 138° 32' 42" by chronometric measurements 

 from Fort Macquarie, Sydney. In the " Saihng Directory, 1868," Glenelg 

 flagstaff is the observation spot. I can find no record of any special 

 determination of Snapper Point ; but in the '* Sailing Directory " of 1876 

 it is made the observation spot, with a longitude of 138° 31' 00", deduced 

 by time signals from Melbourne Observatory. This was altered again 

 in 1883 to 138° 30' 05", or 9hrs. 14min. 3-37secs., as the result of tele- 

 gTaphic signals from Greenwich, iia Singapore and Port Darwin." 



At the request of Captain Hutchison the mast at Snapper Point 

 was connected by triangulation with the Observatory during 1868, 

 and the difference of longitiide thus computed to be 4' lo"-6 of arc, 



( 1 ) By the term lunar distance is meant the process of finding the true angular 

 distance of the moon from the sun, or from a star, by observation of their apparent 

 distances and altitudes, which, compared with local time and certain data in the 

 nautical almanac, gives the longitude. 



