While thus indulging in airy imaginings of the future, darkness gradually closed in, and I became suddenly aware, as so often happens in this world, that all my calculations would have been sound in regard to my finding my way if they had not been based upon thoroughly delusive premises. The cause of my error may be summed up in the one word, basalt. I had forgotten one of the most remarkable geological features of this part of the country, and this is, that only the lower stratum of the range which rises from the east shore of Lake Tiberias is of limestone. All the rest is basaltic, and this formation is of vast thickness. The whole of this district is, indeed, an immense volcanic field, consisting of irregular heaps of amorphous lava and disintegrating scoriæ, with mounds of globular basalt. So that when darkness came on everything below me, as well as all above, seemed suddenly to have become as black as night. The path had disappeared as if by magic, and I called a halt, and we found ourselves on a patch of black rock, with exactly similar patches of black rock all around us. The outlines of the hills had vanished, the path had led us up from the bed of the torrent, so we no longer had that to guide us. To attempt to descend to it would have been madness, as we might have fallen over a precipice in the darkness; indeed, we were afraid to move, except with extreme caution, in any direction. We had a compass and matches, and knew that by keeping due south we might, if no accident befell us, and the rocks permitted a passage, ultimately reach the plateau; but we also knew that the direction of our night-quarters was due cast; but here we ran the greater risk of tumbling into unknown transverse gorges with precipitous cliffs. We cautiously worked south, but our progress soon became barred by thorny brushwood, and we had to face the alternative of a night out-of-doors without water or anything to drink, and a very limited supply of food.