90 Mr. C. Davison. 



cerned is that lying near the centre of the isoseismal 5. Here the 

 beds, which are believed by Messrs. Hill and Bonney to be of pre- 

 Cambrian age, " are elevated in an elongated dome-shaped anticlinal 

 of which on?y one-half is visible, and the vertex points to the south- 

 east ; so that denudation has exposed the lowest beds at the northern 

 end, 'and the others lap round them in rudely elliptical zones.'' 

 Along the anticlinal axis, the direction of which is approximately 

 north-west and south-east, but in the neighbourhood of Woodhouse 

 Eaves more nearly W. 40 N". and E. 40 S., there appears to run a 

 considerable fault, the beds on the south-west side being older than 

 those on the north-east. The course of this supposed fault is indi- 

 cated on the map by a dotted line. If the fault be a normal one, but 

 of this there is no certainty from geological evidence, it must clearly 

 hade to the north-east. 



The close correspondence between the probable position of this 

 fault and that of the fault suggested by the seismic evidence allows 

 us to infer, I think, with some degree of confidence, that the Leicester 

 earthquake was caused by a slip of the anticlinal fault of Charnwood 

 Forest. 



Nature of tlie Earthquake Phenomena. 



In the present section I will first give a few brief descriptions of 

 the earthquake, and will afterwards present a summary of the 

 evidence from different points of view. The first group of accounts 

 are from places near the major axis of the disturbed area, the second 

 from places near the minor axis of the isoseismal 5, which may be 

 regarded as the minor axis of the disturbed area. 



1. (a.) Accounts from places between the north-west end of the 

 major axis and the isoseismal 5: Quarndon, a dull rumbling sound 

 first heard, as of some very distant explosion, lasting about five 

 seconds, followed without any interval by a quick tremulous motion, 

 which gradually increased in intensity, and then died away, intensity 

 3. Derby, a tremulous motion, increasing in intensity for three 

 seconds, and then decreasing until it ceased after one second more, 

 intensity 3; a soft, slightly tremulous sound heard for two seconds 

 before the tremulous motion began, increasing in intensity and 

 ending rather abruptly just before the tremulous motion was 

 strongest. Spondon, a tremulous motion for two or three seconds, 

 preceding more prominent vibrations which lasted for two seconds 

 more and were not followed by tremulous motion ; a rumbling sound 

 like that of a heavy cart passing close to the house, the beginning 

 and end of which coincided with, or slightly preceded, the beginning- 

 and end of the shock respectively, the sound loudest when the vibra- 

 tions were strongest. Weston-on-Trent, a slight tremulous motion 

 for about two seconds, succeeded by two series of vibrations, each 



