Proceedings of the British Association. 



573 



impulses of elevation, as far as anything was known of them, were 

 slow, acting over wide areas, and disrupting and contorting moun- 

 tain masses. Nothing was more certain than that continental masses 

 had risen, and were rising, in our own time : Norway, for example, 

 with curvations so slight as to be invisble. In the Southern and 

 Pacific Ocean, Mr. Darwin had pointed out large areas, rising and 

 subsiding, some of them 3,000 or 4,000 miles in diameter. He stated 

 that he was not prepared to grapple with a theory which was so imper- 

 fectly explained, and without diagrams ; he only wished phenomena not 

 to be pressed into its service, which either bore not upon it at all, 

 or were, perhaps, opposed to it — namely, the phenomena of the British 

 chains. He lastly endeavoured to shew how, in many cases, a revers- 

 ed dip might be produced after the first protrusion of a central granitic 

 axis. Prof. Sedgwick concluded with a merited compliment to the 

 American nation for the elaborate surveys they had published, of 

 which the present memoir was an example ; the facts of which must 

 in the end, serve along with similar phenomena to form the base of 

 a legitimate theory. 



' Report of Committee appointed at the Meeting of the British 

 Association, held at Plymouth in 1841, for Registering Shocks of 

 Earthquakes in Great Britain.' 



The Report commences with a list of shocks observed at Comrie, in 

 Perthshire, since the date of that given in, last year, to the Association 

 by the Committee. (Athenceum, No. 719.) Sixty distinct shocks are 

 recorded as having occurred on thirty-six different days, between July 

 23rd, 1841, and June 8th, 1842. Twelve of these are registered as 

 having occurred on the 30th of July, 1841, being the greatest number 

 hitherto noticed in the course of a single day. The instruments em- 

 ployed to indicate the shocks were those described last year. ( Athen. 

 No. 719.) The new instruments provided by the Committee have not 

 (with one exception) yet been affected, having been but a short time 

 at their respective stations ; and out of the sixty shocks above men- 

 tioned, there were but three occasions on which these instruments 

 were moved. 



1. On the 26th July, 1841, the inverted pendulum set in the steeple 

 of Comrie parish church, was thrown about half an inch to the west, 

 apparently indicating a horizontal movement of the ground eastward, 

 to the same amount. An upward heave of the ground, to the extent of 

 half an inch, was also indicated by two instruments, one of them being 

 a horizontal bar, described in the course of the Report. — 2. The next 



