BRITISH ASSOCIATION. 



243 



thing was known of them, were slow, acting over wide areas, 

 and disrupting and contorting mountain 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 invisible. 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 imperfectly explained, and with- 

 out 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 Bri- 

 tish chains. He lastly endeavoured to show how, in many 

 cases, a reversed dip might be produced after the first pro- 

 trusion of a central granitic axis. Professor Sedgwick con- 

 cluded 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. 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 hav- 

 ing occurred on the 30th of July, 1841, being the great- 

 est number hitherto noticed in the course of a single day, 



VOL. I. — NO. VIII. s 



