518 
VOYAGE TO THE 
CHAP, with fine weather, with the exception of fogs, which are very prevalent. 
Shocks of earthquakes are frequently felt during the winter ; and 
June, Wittrein and his companion repeatedly observed smoke issuing from 
the summit of the hills on the island to the northward: that island 
in which we anchored is entirely volcanic, and there is every appearance 
of the others to the northward being of the same formation. They have 
deep water all round them ; and ships must not allow their safety to de- 
pend upon the lead, for although bottom may be gained at great depths 
between some of the islands, yet that is not the case in other directions. 
We noticed basaltic columns in several parts of Port Lloyd, and 
in one place Mr. Collie observed them divided into short lengths as at 
the Giant’s Causeway : he also remarked at the head of the bay in the 
bed of a small river, from which we filled our water-casks, a sort of 
tesselated pavement, composed of upright angular columns, placed side 
by side, each about an inch in diameter, and separated by horizontal 
fissures. It was the lower part of the Giant’s Causeway in miniature. 
Many of the rocks consisted of tuffaceous basalt of a grayish or greenish 
hue, frequently traversed by veins of petrosilex ; and contained numerous 
nodules of chalcedony or of carnelian, and plasma f The zeolites are 
not wanting ; and the stilbite, in the lamellar foliated form, is abundant. 
Olivine and hornblende are also common. The drusses were often 
found containing a watery substance, which had an astringent taste 
not unlike alum, but I did not succeed in collecting any of it. 
The coral animals have raised ledges and reefs of coral round 
almost all the bays, and have filled up the northern part of the harbour, 
with the exception of Ten Fathom Hole, which appears to be kept 
open by streams of water running into it ; for it was observed here, that 
the only accessible part of the beach was at the mouths of these streams. 
1 have before observed, that the hills about our anchorage were 
wooded from the water’s edge nearly to their summit. There were 
found among these trees, besides the cabbage and fan-palms, the tamanu 
of Otaheite, the pandanus odoratissimus, and a species of purau ; also 
some species of laurus, of urtica, the terminalia, dodonaea viscosa, eleo- 
carpus serratis, &c. We collected some of the wood for building boats, 
and found it answer very well for knees, timbers, &c. 
