The dwellers in caves very generally chose for their habitations the sunny side of the ravines and valleys, and the spots which commanded a wide view, and, therefore, their remains are to be looked for in those places, rather than on the cold and sunless sides, or where an enemy might approach without observation.
The Scientific Methods of Cave-digging.
The exploration of an ossiferous cavern with sufficient accuracy to be of scientific value, may be carried out in all tunnel caves, or those extending horizontally into the rock, by one of the three following methods which may be adapted to the local conditions:—
The first step to take in all cases is to make a plan of the entrance, and to cut a passage down to the rock at the entrance, so as to obtain a clear idea of the sequence of the strata. In the hyæna-den at Wookey Hole, we first of all cut a passage through the cave-earth which extended from the roof to the floor, and then removed the earth on either side in blocks, until ultimately the chamber and passages described in the [eighth] chapter were cleared of their contents. Our work was measured every evening, and each bone and object found was labelled with the date which was recorded on the ground plan. Vertical sections were also taken from time to time. This mode, supplemented by constant supervision of the workmen, was sufficiently accurate to satisfy the demands of scientific research.
The Victoria Cave, where the demarcation between the strata was very distinct, was explored, while the work was under my direction up to September 1873, in a somewhat similar fashion. It was, however, impossible on account of the great depth of the deposits to cut a passage down to the rock at the entrance. We therefore examined the superficial strata throughout the cave, merely gauging the thickness of those below by sinking three shafts. Where a cave is sufficiently high to allow of the work being carried on, it is better to clear out one stratum before another is disturbed.
The most elaborate and perfect method of cave exploration is that which has been used by the committee in Kent’s Hole, under the superintendence of Mr. Pengelly, who writes as follows:[274]—
“The following is the method of exploration which has been observed from the commencement, and which it is believed affords a simple and correct method of determining the exact position of every object which has been found.
“1. The black soil accessible between the masses of limestone on the surface was carefully examined and removed.
“2. The limestone blocks occupying the surface of the deposits were blasted and otherwise broken up, and taken out of the cavern.
“3. A line termed the ‘datum-line,’ is stretched horizontally from a fixed point at the entrance to another at the back of the chamber.