Geology of the Bermudas. ' 439 



The Crystal Cave is now entered by stairs to about a depth of 

 90 feet, and then progress is made on floating pontoons. The water 

 in this cave is some 12 to 20 feet deep ; the lower parts are completely 

 submerged at all times of the tide, for the water inside rises and 

 falls with the tide outside, the average fall and rise of which is about 

 4 ft. 7 in. 



There are three very large stalagmites as well as several smaller 

 ones, but the larger ones challenge attention by their great size. The 

 gangway passes quite close to the largest, which as nearly as we 

 could judge is some 7 feet in diameter at the base, about half that at 

 the summit, and at least 10 feet high. It is much larger than the 

 ' Milne ' stalagmite, now in the Edinburgh Museum, which was sawn 

 off in 1819 by Admiral Sir David Milne from the cave near Tom 

 Moore's Calabash-tree. This was lift. 3 in. high, 25 inches in 

 diameter, and weighed 3|- tons. 1 (The diameter at the apex was of 

 course less.) The stalagmite at the Crystal Cave weighs at least 

 12 tons. 



These huge masses of carbonate of lime were formed when the cave 

 stood at a much higher level, since it would be quite impossible for 

 them to form in their present position under sea-water. Moreover, 

 there must have been a much greater rainfall than at present to 

 have dissolved and scoured out this magnificent cave, and this points 

 to a land surface at a higher level for the cooling and precipitation of 

 aqueous vapour. 



VII. The Grey Rock from the Deep Cut at Warwick {vvlgo 

 'Khyber Pass'). (PI. XXI, Fig. 1.) 

 This rock is the most puzzling of all the rocks from Bermuda. In 

 the Museum at Hamilton is a small mass of hardened rock from 



Fig. 5. Peneroplis pertusus, grey rock, ' Khyber Pass,' Warwick East, 



Bermuda. X 40 nat. size. 



a depth of 32 feet in the Paget formation, found in blasting the road. 



This road has been deepened from time to time so as to make the 



gradient more easy for carts and horses. 



Pimlicoes come in. The Cahouse continue til the beginning of June in great 

 abundance, they are bigger bodied than a Pigeon and of a very good and firm 

 flesh. They are taken with ease if one do but sit downe in a darke night and 

 make a noise, there will more come to him than he will be able to kill : some 

 have told me that they have taken twelve or fourteen dozen in an hower." 

 (The names are onomatopoeic, from the cries of the birds. The pimlico has 

 been identified as the ' dusky ' or Audubon's shearwater ; vide antea.) 



1 Verrill, "The Bermuda Islands: Geology": Trans. Conn. Acad. Arts 

 Sci., vol. xii, p. 85, note. 



