Page:A Voyage to Terra Australis Volume 2.djvu/16

12

The coast lies nearly north, and except Sandy Cape, appears to be mostly of free stone, which I have not found to produce any effect upon the needle; and what is remarkable, on comparing my observations with those of captain Cook, it appeared that little or no change had taken place in the variation, during thirty-two years; for wherever our observations were taken with the ships heads in the same direction, there the same variation was obtained to a few minutes.

Within Break-sea Spit, an amplitude gave the variation when corrected, 7° 25′ east; and one taken at the anchorage near Sandy Cape, but uncorrected, the direction of the ship's head being unknown, 7° 57′ east. There is little doubt that on bringing the land to the eastward of the ship, the variation was diminished at least half a degree: the stone of Sandy Cape is granitic.

In the morning of August 1, the wind was from the southward, and we steered across Hervey's Bay, towards a sloping hummock on the west side, where my examination in the Norfolk had terminated. The soundings increased from 7, gradually to 18 fathoms, and afterwards decreased till half past four in the afternoon; when the sloping hummock bore S. 2° E. eight miles, and we had no more than 3½ fathoms near some dry banks and breakers, which extend out three miles from two shallow inlets in the coast. At dusk the anchor was let go in 6½ fathoms, mud and sand; the shallow inlets to the south being distant 6 miles, and the sloping hummock bearing S. 17° E. In captain Cook's chart, the width of Hervey's Bay is fifty-nine miles, which had appeared to me too great when here in the Norfolk; and I now made the distance, from the north-west extremity of Sandy Cape to a low point running out from the hummock, to be forty three miles by the time keepers. Such errors as this are almost unavoidable without the aid of these instruments, when sailing either along a coast which lies nearly on the same parallel, or where no land is in sight to correct the longitude by bearings. From Port Jackson to Sandy Cape, captain Cook's positions had been found to differ from mine, not more than