Page:A Voyage to Terra Australis Volume 2.djvu/227

Caledon Bay.]

that by survey worked back from the fixed point in Caledon Bay, meet each other on Jan. 5 p.m. at Connexion Island; and the difference was there found to be 2′ 41″, which the time keeper gave more to the east. This may have arisen from Observation Island being laid down in a longitude too great by that quantity, or Caledon Bay too little, or from a small error in each; but the time keeper was not thought entitled to such perfect confidence, as to cause an alteration to be made in these stations. The difference of 2′ 41″ is therefore corrected by applying −16″,3 of longitude per day to the time keeper, from Observation to Connexion Island; Groote Eylandt is laid down mostly from the time keeper, with the fixed correction −2′ 41″ all round; and from thence to Caledon Bay the chart is constructed from bearings and observed latitudes.

At my different stations on shore, the variation seemed to be between 2 and 2° 20′ east; except on the north-east end of the outer island in the entrance, where it appeared to be no more than 1° 30′.

The rise of tide in Caledon Bay was so small, that nothing certain could be determined on board, either upon the quantity or the time; but it appeared from the observations of lieutenant Fowler at the tents, that there were two tides in the day, the rise of which varied from 3 feet 10, to 4 feet 10 inches; and that the time of high water took place at nine hours and a half after the moon passed over and under the meridian.

On board the ship, the range of the thermometer was from