260 Mr D. Milne on Earthquake- Shocks in Great Britain, 



mences with a still earlier era. These catalogues will be 

 afterwards noticed, as affording some inferences remarkably 

 accordant with those suggested by our British register. 



Even within the period embraced by this register, there are 

 many notices of shocks which have been purposely omitted, 

 from the impossibility of discovering the month in which they 

 occurred. It is possible, also, that there are many shocks which 

 have been omitted, in consequence of the works in which they 

 are described having been overlooked. Even since the forego- 

 ing register was framed and printed, the author has found some 

 additional information regarding particular shocks, of which 

 he will avail himself in the present part of his Memoir. 



In drawing attention to the more important inferences which 

 the foregoing register seems to warrant, it is intended to notice, 

 firsts the facts which explain and illustrate the nature and cha- 

 racter of earthquake-shocks ; and, next, the facts which appear 

 to be directly or indirectly connected with the cause of the 

 shocks. 



Perhaps it is here proper to explain, that in the brief notices 

 given in the register of effects produced by the shocks there 

 recorded, it has not been thought necessary to include a de- 

 scription of all the effects related of such shocks. Much might 

 have been added to the accounts which will there be found, of 

 chimneys rent and thrown down, — of walls cracked and over- 

 turned, — of slates on house-tops that rattled and were broken, 

 — of bells set a-ringing, and of the consternation produced 

 both on human beings and on the lower animals. Little or 

 no advantage could result, from swelling the register with such 

 details. The object has been, rather to select and exhibit ef- 

 fects which seem calculated to throw light on the nature and 

 causes of earthquake-shocks. 



1. Nature of the Shocks. — ^They seem to produce a sensation 

 of two things, perfectly distinct. In i\\e first place, the earth's 

 crust at the place where the shock is felt, seems to be always 

 thrown into a tremulous state, producing feelings very similar 

 to those experienced on board a steam-boat, when, in blowing 

 off the steam, or by too great a draught in the funnel, the plates 

 of the boiler communicate a tremulous motion to the deck. The 

 peculiar state into which the earth's crust is put, seems to bo 



