Correspondence — ^^j j * c-> * ^ 93" 



The author gives a summary of previous writings beai'ing upon 

 the geology of the Bermudas ; but bis own researches point to 

 a rather more complicated series of changes than those which have 

 been inferred by other writers. The formation of the " base-rock " 

 or " beach-rock " occurred at some period which cannot be accurately 

 ascertained at present, owing to the fragmentary nature of the 

 included fossils. It may have been formed in Pleistocene or even 

 late Tertiary times. After its formation it was converted into 

 a dense limestone and then eroded, probably by subterial agents, and 

 finally attacked by the waves at an elevation of at least 15 feet 

 above present sea-level ; during this stage it was covered by beach- 

 deposits of pebbles and shells, which were accumulated in a period 

 so recent that the contained fossils are of the same species as the 

 organisms living in the neighbouring sea. Then followed an 

 uplift, during which land-shells lived on the beach -deposits ; but 

 these were soon covered by blown sand, the principal accumulations 

 of the islands, and the outline of the islands was perfected by the 

 action of the winds. This was done at an elevation which was at 

 one time certainly as much as 40 or 50 feet above present sea-level. 

 The author adduces evidence of a depression since the accumulation, 

 causing land to disappear and the outline of the area to become very 

 irregular; and he proves that these changes cannot be accounted for 

 solely by erosion, as some have maintained. Tliere are indications 

 that the land is at present quiescent. It appears, then, that most of the 

 work of construction of the Bermudas has been done in recent times. 



COB/IRBS IF'OJsr JDIBJ^rCS. 



INDICATIONS OF EARTHQUAKE. 



Sir, — The accounts of the recent earthquake which I have seen in 

 an English paper, include references to the accompanying sound as 

 resembling the noise " of a rushing wind." This recalls an observa- 

 tion of my own showing that the appreciation of such sounds varies at 

 times from the subterranean or other rumblings so often recorded. 



It was early in the seventies when I was reading over the fire one 

 night in my " den " at Devonshire Cottage, Murree, elevated about 

 7,000 feet on the foot-hills of the Punjab outer Himalaya. The fire 

 had burned low in a grate surmounted by an arch cut from a sand- 

 stone slab, which was cracked upwards from the crown, and for more 

 warmth I had placed my feet against the slab on each side of the 

 crack. A little later I noticed a " soughing " or sound of " rushing 

 wind," as I thought, coming up the valley from Tret, through the 

 pine forests. Thinking this strange on a calm night I looked up and 

 over my book, when I distinctly felt the motion of one of the small 

 eai'thquakes not very uncommon in the Upper Punjab, and saw the 

 old crack referred to open between my feet for more than half an 

 inch, and close as the seismic wave passed onwards. 



It may be this which fixed the character of the sound in my 

 memory ; at any rate, I do not recollect another earthquake 

 accompanied by the sound of " rushing wind." 



Davas Darf, Suisse, , ^ . ^ \ 



December 19, 1896. ^"l ^^ 



