BRITISH ASSOCIATION MEETING. 



443 



roof, eight feet in thickness, was of sound unbroken limestone, and that the 

 stones and other materials could not have fallen in from above ; but then, nnfor- 

 tunately, they, with equal positivity, affirm that there was no external opening 

 whatever — vertical, terminal, or lateral ; and, in their endeavours to account for 

 the presence of the bones and rock-debris in what they believe to have been 

 merely a blind cavity in the rock, they incline to the opinion that the rock has 

 grown round the accumulation wliich it contains — just as some persons ask us 

 to believe that rocks have grown around live toads and froo's. 



It will be remembered that in Mr. Wliidbey's description of the two first 

 caves he most decidedly ^ives it as his opinion that there never were any indi- 

 cations of a communication with the sui'face ; indeed, in his first letter " he 

 saw no possibility of the cavern having had any external communication 

 through the rock in which it was inclosed;" and although in his letter to Mr. 

 Barrow, descriptive of the third cave, he admits that " there were joints not so 

 close but that water might have dripped into the cavern," he adds " I have 

 not seen anything to encourage the idea that the cavern had a communication 

 with the surface since the flood." 



In his " Reliquiaj Diluvianse," Dr. Buckland, who had visited Oreston, says, 

 " In speakmg of the bones at Oreston in my former paper on Kkkdale, I had 

 expressed a decided 0]3inion that the caverns in which they occur must have 

 liad some communication with the surface, through wliich the bones may have 

 been introduced ; and Mr. T\^iidbey has since found reason to adopt the same 

 opinion."* 



The late Sir Henry de la Beche, in his " Report on the Geology of Corn- 

 wall, Devon, and West Somerset," says " In one of our visits to the Oreston 

 quarries we obtained two teeth of a rhinoceros at the bottom of a narrow 

 fissm-e, amid a dark clay, apparently impregnated with aiiunal-raatter, in an old 

 unnoticed part of an excavation. Considerable angular masses and smaller 

 fragments of limestone often occur in the ossiferous and other fissures, and it 

 can be readily nnderstood that before these cracks became fiUed by fragments 

 detached from the sides, and by the loam and sand, multitudes of animals 

 rangmg the ground above conld have fallen into them, more particularly when 

 chased by beasts of prey, often themselves the victims of then- own eagerness 

 and voracity either diiriug the chase, or when the dead animals were visible 

 in the fissures."f 



As the workmen entered the cavern at the top, in the ordinary course of 

 working vertically downwards the greater part of the roof was destroyed before 

 I visited Oreston ; nevertheless a portion, and, I think, a snfiicient portion for 

 the purpose, remamed. It was evidently a mass of limestone -breccia, made up 

 of large angular fragments cemented by carbonate of lime, and easily enough 

 mistaken, without a careful inspection, for ordinary lunestone somewhat rich 

 in coarse veuis. I caUed the attention of the workmen to it, and explained my 

 opinion respecting its origin ; to this they oifered no objection further than 

 that it was solid, and required blasting quite as much as the limestone else- 

 wliere. This appears to have been Mr. Whidbey's test ; for, in his first letter 

 to Su* Joseph Banks ; he says, " In the contract of quarrying there are two 

 prices, one for rock, another for clay, earth, and mbbish ; and two officers at- 

 tend, one for the Crown, and the other on the part of the contractors, who 

 measure the contents of aU caverns that contain clay, or other soft materials : 

 it is only necessary to mention that these officers state that the rock surround- 

 ing the cavern Avas equally hard with the other parts, requiring the same force 

 to blast, and that the quari-ying vras paid for accordingly."! 



* Reliquse Diluvianae, page 80. 

 t De la Beclie's " Report on Cornwall," &c., p. 113. 



X Pbilosopliical Transactions, 1817, p. 177. ^ 



