Page:A Voyage to Terra Australis Volume 2.djvu/300

288 there are dry banks, also frequented by birds, and the easternmost bank is covered with wiry grass and some shrubs, and is called Bird Islet. Their situations are these:

The bearing and distance of these dangers must be successively worked, and a course steered so as to leave them half a degree to the westward; but for fear of an error in the time keeper the latitude 23° 20′ should not be passed in the night. It is better to make short tacks till daylight, than to heave to; and allowance should be made for a probable current of one mile an hour to the north-west. A good look-out must be constantly kept; and a confidential officer should now go to the mast-head every two hours in the day and to the fore yard at night, to listen as well as look; for in dark nights the breakers may often be heard before they can be seen. It will not be amiss, if the time of the day be favourable, to make Bird Islet, which is well settled, in order to see how the longitude by time keeper agrees; and should it err, the difference, or more, must be added to, or subtracted from its future longitudes; for it is most probable that the error will continue to augment the same way, more especially if the time keeper be a good one.

Having passed Wreck Reef, there are no other known dangers near the route for Torres' Strait, till we come to Diana's Bank; but as others may exist, it will be prudent to lie to, or preferably to make short tacks in the night, during the rest of the passage to the Strait. In light nights, however, and moderate weather, there would be not much risk in closely following the Cumberland's track, carrying no more sail than will allow of the ship being conveniently hauled to the wind; but if an unusual number of boobies and gannets be seen in the evening, there is strong suspicion of a bank and reef being near; and the direction which the birds take, if they all go one way as is usual in an evening, will nearly show its bearing. The longitude of Diana's Bank, according to M. de Bougainville, is 151° 19′