On the caves and fissures in the western district of the Mendip Hills

Abstract

The first cavern described in this paper is situated at Uphill, at the very western extremity of the Mendip Hills. Its present entrance is about midway in a mural face of transition limestone, about a hundred feet high. The fissure leading into it is nearly vertical, and was discovered by some quarry-men casually intersecting it. Some bones and teeth being found there, the author was induced to pursue the exploration of the fissure; in the course of which he discovered bones of the rhinoceros, hyæna, bear, ox, horse, hog, fox, polecat, rat and mouse, and also of birds. The bones of the animals of the larger species were so gnawed and splintered, and evidently of such ancient fracture, that no doubt could exist of the cave having been a hyæna’s den, similar to Kirkdale and Kent’s Hole. All the ancient remains were found in the upper regions of the fissure, and were so firmly imbedded in the detritus, as not to be extracted without difficulty with the pick-axe. Further on he found a wet tenacious loam, abounding with an innumerable quantity of bones, belonging exclusively to birds. After working six days he came to a cavern, ten or twelve feet high, extending about forty feet from north to south, and varying from eight to twenty feet from east to west; the floor of which was covered with bones of sheep: and on digging into the mud and sand of which it consisted, the bones of sheep, birds, cuttle-fish, and foxes, were discovered. Some fine stalactites depended from the roof, and partial spots of stalagmite appeared on the floor. In a fissure that branched from the mouth of the main entrance there were found, among the sand, a piece of black Roman pottery, and two coins, one of Didius Julianus, and the other of Julia Mammæa, together with bones of sheep, cuttle-fish, foxes, and birds. The author considers that there exist evidences of the operation of water at three distinct periods of time:—the first indicated by the bones of the hyæna, and the other gnawed bones firmly imbedded in the diluvial detritus: the second, when sand was deposited by the sea in the second fissure, that washed in through the vertical chimney, and that inundated the whole valley up to Glastonbury: the third irruption of the sea occurring within these fifteen hundred years, and choking up the adit from the level by which the sheep and foxes had entered, floating in the bones of the cuttlefish, and depositing the thin crust of mud which covered the sand. The coins and pottery he supposes to have been introduced through this entrance from the level.

The fracture mechanics of slow crack growth in polyethylene

“…This explanation was never seriously pursued because different polyethylene resins contain different concentrations of pigments and particle sizes and yet they all agree with (1) and (2). Craze growth theories by Williams and Marshall [5] and Kinlock [6] which are based on relaxation controlled growth, do not apply because their exponent in (1) would vary from 10 to 40 when based on the relaxation times for the elastic modulus and the yield point in polyethylene. In this paper a fundamental theory is presented for the rate of slow crack growth which agrees with the precise experimental data represented by (2).…”