100 



Now Mr. Tidrleman describes this upper clay or cave 

 earth as gradually thickening from the entrance towards the 

 rear of the cave, and he places a laminated clay between it 

 and the lower cave earth, which he also describes as dipping 

 gradually from the entrance towards the rear of the cavern, 

 and he distinctly pronounces this laminated structure to be 

 evidence of its glacial origin, and he supposes it to have been 

 deposited in the following manner : — 



" Let us imagine a glacier or an ice sheet passing by the 

 mouth of the cave and partly blocking the entrance with its 

 rubbish * * * * the glacier melts by day and usually 

 (though not always) freezes by night. The moraine rubbish 

 hinders the coarser debris from entering the cave, but gives 

 passage to glacier water charged with fine mud. The glacier 

 by its grinding keeps the water charged with mud, and the 

 frequent change from daily flow to nightly inaction, gives 

 rise to that close lamination, which is its characteristic 

 feature." 



With all respect to the opinion of so high an authority, I 

 altogether deny the possibility of this being the true expla- 

 nation, for the following reasons : — 



(a) Glaciers do not deposit fine mud in lateral moraines 

 150 or 200 feet above the base of the glacier; and even if 

 they did, it is not possible that such mud could flow into 

 a cavern closed at its end as here described. 



(6) The laminated clay occurs in the cave on the surface, 

 at a 'point ivhere it can only he of most recent origin, near 

 the dome which terminates in a " pot hole," and by which 

 it has evidently been only recently introduced ; and similar 

 clays occur in other caverns, where glacial action as above 

 desd'ihed could not have obtained. 



After a most careful examination I am perfectly satisfied 

 that Mr. Tiddeman has overrated the importance of this 

 laminated clay, and that his theory is altogether erroneous. 



