VOL. LXI.] PHILOSOPHICAL TRANSACTIONS. 141 



of the 2d shaft will account for 80 yards being wet ; as so many might coil up in 

 the water, let it have been ever so shallow, and as the rest, beyond the real depth 

 of the chasm, might coil up either in the great or little cave. Again, the many 

 craggs on each side the first shaft, and probably also on each side the 2d, must 

 retard any stone in its fall; and by that means will account for the length of time 

 a body takes in descending ; which must be a great deal longer than if it fell in 

 open space: and hence Dr. Short (who has given a calculation, formed from the 

 time of the descent of heavy bodies, according to the Newtonian principles of gra- 

 vitation) was misled to conclude, though very ingeniously, that this chasm was 

 422 yards deep. And lastly ; the falling of stones into the water, at the bottom 

 of the 2d shaft, and the increase of the sound thus made, partly from the rever- 

 beration at the sides of the great cavern, and partly from the form of the upper 

 shaft, which is not very unlike that of a speaking trumpet, might occasion that 

 astonishing noise, which is said to have been heard at various times formerly, on 

 throwing stones into this gulf; but which has not been heard of late years, in a 

 manner at all agreeable to old reports. i,i 



And as both Mr. Lloyd, and also a miner's wife, from whom K. had his in- 

 formation, mentioned there being water at the bottom of the 2d shaft, it appears 

 highly probable, that this water is the continuation of a subterraneous river ; and 

 indeed of that very river which runs out of the mouth of the great cavern at 

 Castleton : for it is observed by the country people in the neighbourhood, that 

 there is a large quantity of grit stone grows in the earth near Elden Hole, but 

 none near Castleton ; and yet, on high floods, the river at Castleton washes 

 great quantities of fragments of that very grit-stone out of the mouth of Castle- 

 ton cavern. 



There is also a tradition, which however ridiculous, ought to be preserved. 

 Many years ago, an old woman, hunting her goose, it fell down into Elden Hole; 

 but some days after, she heard it was seen at the mouth of Castleton cavern, and 

 actually received it safe again from thence : the goose having, by the fluttering 

 of its wings, preserved itself from being dashed to pieces in its fall ; and having 

 found its passage safely through the subterraneous river. >t;,j 



XXX II. Account of Two New Tortoises. By Tho. Pennant, Esq., F.R.S. p. 2(56. 

 The first of these was communicated by Dr. Garden, of Charlestown, in South 

 Carolina, in the following words : • I now come to speak of a species of turtle 

 or tortoise, peculiar to our southern rivers. We call it the soft-shelled turtle; 

 because, when alive, the covering looks like leather, very smooth and pliable, 

 without any appearance of bone in it. It is very swift and fierce. They are not 

 commonly got here in Charlestown, though by chance this last summer I had 



