C. Davison — British Earthquakes 0/1890. 451 



line of tlais area corresponds to an isoseismal of intensity IV. or 

 nearly so ; it contains a little more than 60 square miles. 



Throughout the disturbed area, the shock seems to have consisted 

 of a single vibration ; no tremulous motion being noticed either 

 before or after. At Boston Spa, it is said to have resembled '* an 

 explosion, or the sudden and loud banging of a subterranean door." 

 At Walton, a village close to the epicentrum, the movement was 

 lateral only, no vertical motion being perceptible. 





\ 



\.^ * Cliffard. / 



„ _ -^ ^oitoTZ'J'ercz/ 



Estimates of the duration are variable, f^nd probably include that 

 of the accompanying sound in one or two cases. At Collingham, 

 the shock seemed to be instantaneous. Tt is stated to have lasted 

 a second or two at Boston Spa, two s<- mds at Hunsingore, about 

 three seconds at Walton, and about ten s ""onds at Tockwith. 



The intensity was IV. at Askham Eichard, Bilbrough, Boston Spa, 

 Cowthorpe, Spofforth, Tockwith, and Walton ; and III. at Bolton 

 Percy. 



Sounds were heard accompanying the shock at eight places at 

 least ; from eight others no record is given on this point ; at three 

 places, Askham Richard, Bolton Percy, and Spofforth, it is expressly 

 stated that no sound was heard. The sound-area was, therefore, 

 somewhat less extensive than the disturbed area. 



The epicentrum is about half a mile N.E. of the village of Walton, 

 and 13 miles N.E. of Leeds. 



Second Shock : June 25, about 1 h. — This shock was felt by several 

 persons at Boston Spa, but I have not been able to obtain any 

 detailed observations. 



