116 
A VOYAGE TO 
[ North Coast. 
1802. 
October. 
Saturday 30. 
Sunday Si. 
covered, lose their adhesive property ; and remaining in a loose state, 
form what is usually called a key, upon the top of the reef. The new 
bank is not long in being visited by sea birds ; salt plants take root 
upon it, and a soil begins to be formed ; a cocoa nut, or the drupe 
of a pandanus is thrown on shore ; land birds visit it and deposit the 
seeds of shrubs and trees ; every high tide, and still more every 
gale, adds something to the bank ; the form of an island is gradually 
assumed ; and last of all comes man to take possession. 
Half-way Island is well advanced in the above progressive 
state; having been many years, probably some ages, above the 
reach of the highest spring tides, or the wash of the surf in the 
heaviest gales. I distinguished, however, in the rock which forms 
its basis, the sand, coral, and shells formerly thrown up, in a 
more or less perfect state of cohesion ; small pieces of wood, pumice 
stone, and other extraneous bodies which chance had mixed with 
the calcareous substances when the cohesion began, were in- 
closed in the rock ; and in some cases were still separable from it 
without much force. The upper part of the island is a mixture of 
the same substances in a loose state, with a little vegetable soil ; and 
is covered with the casuarina and a variety of other trees and shrubs, 
which give food to paroquets, pigeons, and some other birds ; to 
whose ancestors it is probable, the island was originally indebted for 
this vegetation. 
The latitude of Half-way Island, deduced from that of the pre- 
ceding and following noons, is io° 8 ' south, and longitude by time 
keeper corrected, 143 18 east. From the time of anchoring, 
to nine at night, there was a set past the ship to the north-east, of 
half a knot ; it ceased for three hours, then recommencing at a slower 
rate, ran to the same point. Thus far in the strait, the current had 
been found to run at the rate of fourteen miles a day to the 
westward ; and the above set might have been an eddy under the 
lee of the reef, for it seemed too irregular to be a tide. 
At daylight in the morning the south-east trade blew fresh, 
