Lieut. Nelson on the Geology of the Bermudas. 



119 



Fig". 8 (p. 112) exhibiting the section of the cavern which once existed 

 under the North Bastion, and Fig. 14 a section of the ground and its caves 

 near the Magazine Pond at Ireland, are I apprehend sufficient to explain 

 my views respecting the origin of these phenomena, as far as Bermuda is 

 concerned. 



The caves at Walsingham, near the Ferry, are well worth examination, but in point of specu- 

 lative interest, they are inferior to the many and very singular hollows near them, on the neck of 

 land separating Harrington Sound from Castle Harbour ; respecting which, all that 1 can venture 

 to surmise from their sections, their steep and occasionally overhanging sides coated with stalag- 

 mite, is, that they are the remains of former caverns, laid bare by diluvial action. Vertical 

 sections of caves are common enough in the cliffs, Fig. 5, c ; and oblique sections (such as that 

 so well known, close to the Ferry, between St. George's and Hamilton) are not unfrequent on hill 

 sides, 



Tucker's Island cavern was a perfect bijou ; with one splendid exception it has hitherto stood 

 unrivalled amongst the caves of Bermuda. 



This little cavern shown in fig. 5, b, had a length of eighty feet, a breadth of about fifty, a 

 height above the little lake within of at most fifteen, and a depth below its surface scarcely 

 exceeding fourteen. The stalactites were remarkably clear and beautiful, varying from the 

 massive pendent of six or seven feet in length, to the slender incipient fragile tube, which 

 crumbled at the slightest touch. It was a scene not to be readily forgotten, when we launched a 

 little boat into the miner's first and narrow opening, through which the sun shone strongly, and 

 reflecting its light from the face of the water upwards and with power to the sparry fretted ceiling 

 of the vault, illuminated it in a way which can only be appreciated by those who have been eye 

 witnesses of such effects. This cave was shortly afterwards destroyed, as interfering with the 

 safety of the works. 



The irregular density of the rock is exhibited on all scales, from 

 minute flaws and patches to large masses of dry sand ; which more than once 

 occurred during the progress of our excavations, in the heart of otherwise 

 hard, sound rock. Pig. 15 is a sketch of one of these hollows ; and whatever 

 may be the scale of operation, it is just such a form as would have been lef< 

 had the sea extracted its contents. 



Fig. 15. 



