This supposition is totally incorrect, as solidification would have probably ensued before it had proceeded one-tenth of the distance; and such of the asphalt as has undoubtedly escaped from the lake has not advanced more than a few yards, and always presents the curved surfaces already described, and never appears as an extended sheet.' Agreeing with this statement as a whole, I nevertheless cannot but think it probable that a great deal of the asphalt, whether it be in large masses or in scattered veins, may be moving very slowly downhill, from the lake to the sea, by the process of expansion by day, and contraction by night; and may be likened to a caterpillar, or rather caterpillars innumerable, progressing by expanding and contracting their rings, having strength enough to crawl downhill, but not strength enough to back uphill again.
At last we surmounted the last rise, and before us lay the famous lake--not at the bottom of a depression, as we expected, but at the top of a rise, whence the ground slopes away from it on two sides, and rises from it very slightly on the two others.

The black pool glared and glittered in the sun.

A group of islands, some twenty yards wide, were scattered about the middle of it.

Beyond it rose a noble forest of Moriche fan-palms; {149} and to the right of them high wood with giant Mombins and undergrowth of Cocorite--a paradise on the other side of the Stygian pool.
We walked, with some misgivings, on to the asphalt, and found it perfectly hard.

In a few yards we were stopped by a channel of clear water, with tiny fish and water-beetles in it; and, looking round, saw that the whole lake was intersected with channels, so unlike anything which can be seen elsewhere, that it is not easy to describe them.
Conceive a crowd of mushrooms, of all shapes, from ten to fifty feet across, close together side by side, their tops being kept at exactly the same level, their rounded rims squeezed tight against each other; then conceive water poured on them so as to fill the parting seams, and in the wet season, during which we visited it, to overflow the tops somewhat.