Coepang Bay. 2 TERRA AUSTRALIS. 
Lieutenant Flinders took altitudes from the sea horizon, be- 
tween April l p. m. and 8 a. m., for the rates of the time keepers ; 
the mean of which, with the errors from mean Greenwich time at 
noon there on the last day of observation, were as under : 
Earnshaw’s No. 543, slow 57' 1 4^,56, and losing 1 6",J$ per day 
520, fast 1 57 19 ,28, - 33 ,99? 
the rate of No. 543 differing only o",2 from that with which we 
had left Caledon Bay. The longitude given by this time keeper 
on April 1, p. m., with the Caledon rate, was 123 0 39' 8", 4 east, 
or 3' 22" more than the lunars ; and when the Caledon rate is ac- 
celerated , the difference is only 2' 3—' east. This quantity, if the 
longitudes of Caledon and Coepang Bays be correct, is the sum of 
the irregularities of No. 543, during the fifty-one days between one 
station and the other. The time keeper No. 520 had been let 
down on the passage, and its rate being now more than 3" greater 
than at Caledon Bay, its longitude was not attended to at this time. 
In laying down the coasts and islands of Arnhem's Land, the 
bearings and observed latitudes were used, with very little reference 
to the time keepers ; but No. 543, when corrected, did not differ so 
much from the survey as T in twenty-five days. The rest of the 
track, from Wessel’s Islands to Coepang, is laid down by this time 
keeper with the accelerated rate, and the application of a proportional 
part of 2' 3^", its irregularity during fifty-one days. 
Variation of the surveying compass, o* 46' west, 
observed when the ship’s head was E. S„ E.,or 
corrected to the meridian, - - o° 37' east; 
but this variation seems to apply only to Coepang Bay ; for about 
two degrees to the eastward it was i° 4' west, corrected, and one de- 
gree to the south-west it was 1 41' west. 
The flood tick comes from the southward, through Samow 
Strait, and rises from three to nine or ten feet ; high water usually 
took place as the moon passed under and over the meridian, but the 
winds make a great difference both in the time and rise of the tide. 
259 
1803 . 
April. 
