The mysterious influence of the approaching spring had penetrated even into these abodes of darkness, and aroused in the bats a little life after their long hibernation; and their weak, plaintive squeak, which had something impish in it withal, came from every shadowy recess, and from the dark vault overhead. This "Rotunda" should have been called the "Bower of Bats." As they all hung too high to reach by other means, I flung my stick at random upward against the wall, and brought down two of the black masses, that writhed helpless upon the stony floor of the cave. Poor, palpitating things, unable to loose their clutch upon each other's wings, it was hard to say whether they were more disgusting or pitiful. What Eshcol clusters these, to bear back from this Canaan of darkness, saying, "This is the fruit of it!" Such an immense number of bats had harbored and died here from time immemorial, that more than a hundred acres of the earthy floor of the cave had, from their decomposing remains, become impregnated with nitre; and during the years 1812 to 1814, a party of saltpetre-makers took up their residence here. They made great vats in the cave, in which they lixiviated the impregnated earth, and by wooden pipes conveyed it to a place where they boiled the water drawn from the vats. Their rude mechanical contrivances are standing yet, in the same positions in which they were left so long ago; and so dry and pure is the air of the cave, that, though more than half a century has passed, these wooden pipes and vats show no more indication of decay than they did when first put in. In one place my guide dug up from the clayey floor--where it was their custom to feed the oxen employed in drawing the materials to and fro--some corn-cobs, very dry and light, but as perfect as though they were only a few months old. The footprints of the oxen, made in the earth that was then moist, are plainly visible in many places; and the clay has since become almost as hard as stone, so that I found it difficult to make any impression in it with the point of my pocket-knife. A few minutes' walk brought us in front of the "Giant's Coffin," an enormous rock forty feet in length, which has fallen from the ceiling. The resemblance to a coffin is so strangely exact, that, having heard mention of it before coming in, I recognized it at the first glance. The upper part of the rock is composed of a stratum whiter than the rest, and gives it the appearance of having a border of white ornamentation around it, just below the lid. It rests upon a gigantic bier about ten feet high, and a little longer than the coffin, and the effect is as though some kingly son of Anak were lying in state in this huge sepulchral vault.