206 DAVIS: RELATIVE AGE UE THE REMAINS UE MAN IN YORKSHIRE. 
Mr. Tiddeman has estimated to have had a thickness of 700 or 800 
feet. Mixed with the clay or till are huge masses of Silurian grit, 
marked and scratched by their passage from distant localities whilst 
embedded in the ice. Isolated boulders of the same rocks, similarly 
scratched, may be seen scattered here and there on the surface of the 
valley. Covering the bank of glacial clays there is a great thickness 
of fragments of limestone which have been detached from the cliffs 
above, technically denominated " Screes." At the summit of these 
screes, one hundred feet above the bottom of the valley, and at the 
base of a huge overhanging cliff is the entrance to the cave. It con- 
sists of thi'ee large irregular chambers which were filled with debris 
almost to the roof when Mr. Jackson followed his dog through a 
small opening into the cave. He was rewarded by discovering a 
number of Roman coins, along with ornaments and implements in 
bronze, in the earth on the surface. Some of the ornaments were of 
singular beauty ; the bronze base was enamelled in bright colours 
with great taste. Brooches, rings, and fibulte were discovered, which 
are termed by Mr. Franks, of the British Museum, -to be "late 
Celtic," and of British manufacture. Indeed it appears more than pro- 
bable that the centre of manufacture of these beautiful articles which 
were spread over the surface of the then civilized world, was located in 
Yorkshire. Philostratus, a Greek who was attached to the court of 
Julia Domna, the wife of the Emperor Severus, wi^ites, " it is said 
that the barbarians living in or by the ocean, pour these colours on 
heated bronze, that these adhere, gTow as hard as stone, and preserve 
the designs that are made in them." Mr. Franks is of opinion that 
this passage refers to Britain, and if such be the case, it is a reasonable 
assumption that the seat of manufacture would be near that of the 
Emperor's court at York. 
The coins, about twelve in number, date from the reign of Trajan, 
A.D. 117, to that of Constans, a.d. 353, and there were also some 
imitations of bronze coins, wliich are about a.d. 400-500. In addition 
to the coins and bronze objects, a large number of bones of animals, 
which had been used for food, and some bone implements used as 
pins, spindle whorls, and other objects were found. The number ox 
bones of the Celtic short -horns, similar to the cattle of Scotland and 
