OF SOME DEEP BOEINGS IN KENT, 



203 



and the Ashdown Beds about 160 feet — or in all more than 400 feet. 

 We should expect, of course, an underground thinning towards 

 Dover, so that, even supposing the boring there to be in the highest 

 division of the Hastings Beds, it is unlikely that there should be any 

 great further depth to be passed through before a Pre-Cretaceous 

 formation is reached. 



At p. 44 of my former paper, attention was drawn to the chief 

 points that should guide us in selecting sites for trial-borings, for the 

 purpose of finding out the deep-seated rocks of the London 

 Basin, and Dover was mentioned, in each case, as a good site, 

 meaning thereby the neighbourhood, and not merely the town 

 itself. It was therefore with some satisfaction that I saw various 

 newspaper-accounts of the projected trial-boring now being made 

 by the South Eastern Railway Company at the foot of Shakespeare's 

 Cliff. 



My previously expressed opinion, which was shared by my 

 colleague Mr. Topley, is strengthened by the conclusions now come 

 to as to the bottom-beds of the boring at the Convict Prison, where 

 the lower part of the Wealden Series seems to have been struck, at 

 the depth of 849 feet. 



As the well begins at a height of 280 feet above the sea, whilst 

 that of the new boring cannot be much above the sea-level, the 

 latter has a great advantage in being at less vertical distance from 

 the deeper beds. The fact that it has also an advantage from the 

 southerly rise of the beds, may probably be more than neutralized by 

 the inference that it is in that direction that the Lower Greensand 

 and the Wealden Beds are likely, one may say are certain, to 

 thicken. The difference of level taken alone would make the depth 

 to the Wealden Beds some 570 feet at the new boring ; but, for the 

 reasons above stated, one would rather count on a slightly greater 

 depth. 



It seems to me that it would have been a far more satisfactory 

 thing to deepen the existing boring of the Channel Tunnel Company 

 at St. Margaret's Bay, about 2| miles E.ET.E. of the Prison boring, 

 and for good reasons — the first that the trial-boring in question is 

 already 567 feet deep ; the second that it is already some feet in 

 the Gault ; and the third that it is in a direction in which one may 

 reasonably expect further undergound thinning than that of which 

 we have evidence at the prison. 



New Boeing at Stkood. 



In the early part of last year another deep boring in the neigh- 

 bourhood of Chatham was finished, and although it does not add 

 much to our knowledge of the underground beds there, yet it is of 

 interest from the fact of its success in getting water from the Lower 

 Greensand, and from its agreement with neighbouring sections in 

 the thickness of the Gault found, which exceeds the previous record 

 only by 3, 2, and 1| feet respectively. Having been noticed onlj 

 in newspapers, it is worth while to describe it here. 



p 2 



