234 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [Apr. 21, 



wholly uninteresting to the Fellows of the Geological Society, 1 do 

 not hesitate to submit to your notice such facts in connexion with the 

 subject as I have been enabled to collect from unquestionable sources 

 of information. 



The area principally affected comprises that portion of country 

 extending from the Mendip Hills to Bristol, and the village of Hen- 

 bury in Gloucestershire to the north, and probably on to the Severn ; 

 and from the Mendips to the Bristol Channel on the west. 



The geological features of this district consist of old red sand- 

 stone, carboniferous limestone, millstone grit, coal-measures, dolomitic 

 conglomerate, new red sandstone, lias, and oolite, with alluvial patches 

 of some extent. 



The principal line of disturbance appears to have been nearly north 

 and south, running through the southern edge of the Mendips, the 

 city of Wells, Cheddar, Pensford, and Dundry, in Somersetshire; 

 Bristol, Westbury upon Trym, and Henbury in Gloucestershire. 

 The chief focus of oscillation was at Cheddar, where the hill is said 

 to have waved to and fro during several seconds ; and in the alluvial 

 flat or marsh below Cheddar, some houses had the plaster of the 

 ceilings cracked, while in other houses the clocks struck, bells rang, &c. 



At Dundry, an elevated ridge of inferior oolite, about five miles 

 south of Bristol, the shock was sufficiently strong to slam doors, and 

 to rattle the glass and china on the shelves, and even, in some in- 

 stances, to cause apprehension that the chimneys would fall. 



In Bristol and its more immediate vicinity, namely Clifton, Go- 

 tham, and Kingsdown, the shock was of still less intensity, but still 

 sufficient to shake the houses and alarm the inhabitants. Some of 

 the persons who experienced the shock describe it as an oscillatory 

 motion of a few seconds' duration, while others represent it as re- 

 sembling the sensation that would be felt if a heavy body fell to the 

 ground, and by the collision produced a momentary vibration. Others 

 experienced an unusual sensation not easily described. The time at 

 which the shock was felt was about a quarter before six o'clock a.m., 

 on the 3rd of April. 



Some slight effects are said to have been perceptible at thirty 

 iriiles distance from the localities enumerated, but this I have not 

 been enabled to authenticate, though in all probability such may have 

 been the fact. 



No serious damage has occurred, but considerable alarm was cre- 

 ated by the unexpected shaking of houses, &c. The period of oscil- 

 lation did not exceed ten or twelve seconds, and the movement is 

 represented as being accompanied by a low rumbling sound. 



Two shocks are reported as having taken place on Saturday, 

 April 3rd, the first at about three o'clock a.m., and which lasted 

 only two seconds ; but the second, which occurred at a quarter before 

 six o'clock A.M., was of longer duration and more decided character. 



