= Appendix. i 
On the 3d of August, Captain Senhouse of the St. Vincent effect- 
ed a landing in the Hind cutter, and hoisted the British flag, calling 
it Graham Island. The form of the crater was found to be nearly a 
perfect circle, and complete along its whole circumference except for 
about 250 yards on its south-eastern side, which were broken and 
low, not apparently more than 3 ft. high. The height of the highest 
part was found, upon a rough computation, to be 180 ft.; the whole 
circuit of the island was from a mile and a quarter to a mile and a 
third. It bore the general appearane of two longitudinal hills, con- 
nected by intermediate low land sending up smoke and vapor in 
abundance. The circular basin, the centre of the island, was full 
of boiling salt water, of a dingy red color; and the vapor was very 
oppressive, causing nausea and faintness. ._ 
Captain Senhouse informs us that the fragments of rock brought 
away by the Hind cutter are compact and heavy, and that the whole 
surface of the island is dense and perfectly hard under the feet. No 
variety of lava was procured, nor even any jet or streams of lava 
seen; and Mr. Osborne, surgeon to His Majesty’s ship Ganges, states 
that the substances of which the island is composed are chiefly ashes, 
the pulverized remains of coal deprived of its bitumen, iron scorie, 
and a kind of ferruginous clay, or oxided earth. The scorie occur 
in irregular masses, some compact, dense, and sonorous, others light, 
friable, and amorphous, with metallic lustre, slightly magnetic, barely 
moving the loadstone. A piece of limestone was also found thrown 
up with the other substances, having no marks of combustion. There 
were, according to the same observer, no traces of lava, no terra puz- 
_aolana, no pumice, nor other stones, usually found on volcanic hills. 
The principal phenomena attendant on the elevation of Graham 
Island are the form of thé ejected mass and its composition ; and 
~ more information will be contained in the study of these two features, 
- than in any hypothetical surmises on the mode of ejection, and on the 
thodkeics and nature of the action by which this took place. 
~. Tt will at once be observed, in the sketches of the island which 
ae that its appearance differs very much ac- 
accompany this notice, ag 
pany wed. In Fig. 1, it is the 
~ cording to the distance at which it is vie 
“sumn ait of a volcano, a cone of eruption slightly elevated above the 
level of the sea; but, on a nearer approach, its form is found to be 
that of a circular crater with more or less perpendicular walls (Fig. 
2,), like most.of the craters of elevation surrounding the internal 
5 and insulated formations of sup- 
51 
craters of volcanoes, or the island 
Vou. XXI.—No. 2. 
