4»J 



the paper in the Edinburgh Transactions, referred to above, hut tliere seems m^ 

 reason to doubt that the combination <<i an inverted pendulum with a flexible 

 spring at it« base was used to obtain an approach to neutral e(|iiilibriuii). The 

 bending of the spring in this instrument plays the same ])art as the inclination of 

 the stretched sj)ring in the seismometer of § A2, in somewhat more than counter- 

 balancing the overturning ctfi'ct of grnvitv on the linb whin the pendiihun is 

 disj)laced. 



Other appliances intended, jniinarilv, to give information about the hori- 

 zontal movement of the ground during earthcjuakes will be mentioned in 

 Chapter VI.* 



• See also tho Appeivlix. 



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