Page:A Voyage to Terra Australis Volume 2.djvu/280

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268
A VOYAGE TO
[South Coast.

1803.
May.

be off the east end of the middle beach, between it and the rock, in 4 or 5 fathoms; but I cannot answer for the ground there being good, though to all appearance it should be the best in the bay.

The latitude observed from an artificial horizon on the middle beach was 34° 5′ 23″ south; and the longitude of the place of observation, a little east of that before fixed by the time keepers from King George's Sound, (Vol. I. p. 89), will be 123° 9′ 37″,6 east. Mr. Flinders took three sets of altitudes between the 18th p.m. and 21st a.m., from which the rates of the time keepers, and their errors from Greenwich time at noon there of the 21st, were found to be as under;

Earnshaw's No. 543, slow 10′ 59″,53 and losing 19′,63 per day.
520, fast 1 31 54, 28 - 34, 07

At the first observation, the longitudes deduced from the Coepang rates were, by

No. 543,—123° 33′ 37″,5 east.
No. 520,—123 25 22 ,5;

the mean of which is 19′ 52″,4 more than what I consider to be the true longitude; but on using rates equally accelerated from those at Coepang to what were found above, the error becomes reduced to 12′ 11″,6 east; which is the sum of the apparent irregularity of the time keepers from April 8 to May 18, or in 40,2 days. The corrections applied to the longitude during the last passage, are therefore what arise from the equal acceleration of the rates, and from the proportional part of the 12′ 11″,6 of irregularity; and when thus corrected, the time keepers did not appear to differ at Cape Leeuwin and Mount Gardner more than 1′ from the longitude of the former year.

Saturday 21.On clearing Goose-Island Bay we steered eastward, with cloudy weather and a fresh breeze which veered to S.S.W. A small round island, with two rocks on its north side, was discovered in the south-eastern part of the archipelago, and also a reef; neither of which I had before seen, nor are they noticed by admiral D'Entrecasteaux. At 3ʰ 40′ the following bearings were taken: