Page:Journal of the Asiatic Society of Bengal Vol 29.djvu/16

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4
Account of a visit to Barren Island.
[No. 1,

easier ascent for a part of the way, and where a rocky shoulder at about two-thirds of the hight would offer a place to rest. Our ascent commenced at about 2½ p.m., and was certainly the most fatiguing expedition many of us remember ever to have undertaken. The sky was almost cloudless, and the heat consequently was great. The lower third and more of the slope consisted of a powder of ashes gained. A little higher, stones loosening when the foot stepped on them and rolling down in long jumps, were dangerous to any one following.

Arrived at the rocks mentioned, their nature and the manner in which the side of the cone bulged out in their neighbourhood, showed that they marked the point from whence an effusion of lava of the same kind, as we has seen below, had taken place from the side of the cone, not reaching the mouth of the tube at the apex. The last third of the way from the rocks upwards offered a firmer footing, the ashes being cemented by sulphate of lime (gypsum) which, where it was present, formed the white patches we had already observed from a great distance when approaching the island. The ground now became very hot, not however intolerably so, until about 30 feet from the apex a few rocks again offered a convenient seat, not affected by the heat of the ground. There the Aneroid barometer and the temperature of the air were observed in the shade of an umbrella.

About half way between these rocks and the highest point cracks and fissures commenced to intersect the ground, widening higher up to the breadth of several inches, where clouds of hot watery vapour issued from them. They were filled with sulphur, often accompanied with beautifully crystallised white needles of gypsum, and a sulphurous smell also accompanied the vapour (sulphurous acid). This smell was however not very strong and did not prevent us from penetrating the clouds, when we discovered that what had appeared from below as the summit was in fact the edge of a small crater, about 90 or 100 feet wide, and 50 or 60 deep. At that depth it had a solid floor of decomposed lava and tufa and volcanic sand. Its walls were made up of rocks, in appearance like those of the older lava and were highest on the north and south sides. Towards the west the crater opened with a similar cleft, to that which had permitted us