In some places by thrusting our stick down with force, large pieces would break through, disclosing deep fissures, and holes apparently without bottom. These, however, were generally too small to appear dangerous. The width of this ledge is constantly diminishing in a greater or less degree, by the falling of large masses from its edges into the crater; and it is not improbable that in some future convulsion, the whole structure may yet be plunged into the abyss below. Leaving the sulphur banks on the western side behind us, we directed our course along the northern part to the western cliff. As we advanced these became more and more perpendicular, until they presented nothing but the bare and upright face of an immense wall,[73] from eight to ten hundred feet high, on whose surface huge stones and rocks hung apparently so loosely as to threaten falling at the agitation of a breath. In many places a white curling vapor issued from the sides and summit of the precipice, and in two or three streams of clay-colored lava, like some waterfall extending almost from the top to the bottom, had cooled evidently at a very recent period. At almost every step, something new attracted our attention, and by stopping sometimes to look up, not without a feeling of apprehension, at the enormous masses above our heads, at others to gain by a cautious approach to the brink of the gulf, a nearer glance at the equally frightful depth below; at one time turning aside to ascertain the heat of a column of steam and at another to secure some unique or beautiful specimen, we occupied more than two hours in proceeding the same number of miles. At that distance from our entrance on the ledge we came to a spot on the western side, where it widened many hundred feet and terminated next the crater, not as in most other places, perpendicularly, but in an immense heap of broken slabs and blocks of lava, loosely piled together, as they had fallen in some convulsion of the mountain, and jutting off to the bottom in a frightful mass of ruin. Here we had been informed the descent into the depths of the crater could be most easily made, but being without a guide we were entirely at a loss what course to take, until we unexpectedly descried the gentlemen who had preceded us re-ascending. They dissuaded us most strenuously from proceeding further, but their lively representations of the difficulty and dangers of the way only strengthened our resolution to[74] go down, and knowing that the crater had been crossed at this end, we hastened on, notwithstanding the refusal of the guide to return with us.