Port Lincoln.] 
TERRA AUSTRALIS. 
eclipse, as recalculated by Mr. Crosley from Delambre's solar tables 
of 1806, and the new lunar tables of Burckhardt of 1812, differs but 
very little from them : it is 135 0 46' 8" east. 
The rates of the time keepers, deduced from equal altitudes on, 
and between Feb. 27 and March 4, and their errors from mean 
Greenwich time, at noon there on the last day of observation, were 
found to be as under : 
Earnshaw's No. 543 slow o h 30' $0" .5^ and losing 8",43 per day 
520 - 1 9 7, 72 - - 18, 82 
Arnold's No. 176 altered its rate prodigiously on March 1st, and on 
the 2nd it stopped. His watch, No. 1736, varied in its rate from 
7",8i to i",9o, so that it continued to be used only as an assistant. 
The longitude given by the time keepers with the King- 
George's-Sound rates, on Feb. 27, the first day of observation at the 
tents, was by 
No - 543. ^ !5' 9",° ea st- 
520, 135 58 53,55 
176, 136 1 23,95. 
But by allowing a rate accelerating in arithmetic progression, from 
those at King George's Sound to what were obtained at this place, the 
mean longitude by the two first time keepers would be 135 0 52' 16", 
or 7' 25" to the east of the lunar observations ; which quantity, if the 
positions of the Sound and of Port Lincoln be correct, is the accumu- 
lation of their irregularity during fifty-seven days. In laying down 
the coasts and islands from the Sound up to Cape Wiles, the longitudes 
are taken from the time keepers according to the accelerated rates, 
corrected by an equal proportion of the error 7' 25" in fifty-seven days. 
From Cape Wiles to the head of Port Lincoln the survey is made from 
theodolite bearings and observed latitudes, without the aid of the time 
keepers. 
The Dip of the south end of the needle, taken at 
the tents, was nearly the same as in K. George's > 
Sound, being - - - - 640 27' 
Variation of the theodolite at the same place, 1 ^ E. 
VOL. I. Z Z 
