INFLUENCE OF SUSPENSION ON WATCH. 381 



be set approximately to the critical arrangement, 

 and the watch brought to rest and left to itself, it 

 will be seen to commence vibrating through a 

 gradually wider and wider arc until a maximum of 

 vibration is attained. The amplitude of vibration 

 will then diminish, but not to zero ; will increase to 

 a second maximum smaller than the first ; will 

 diminish to a second minimum not so small as the 

 first minimum ; increase to a third maximum 

 smaller than the second ; and so on, until, after 

 several of these alternations, a sensibly steady state 

 of vibration, very closely simple harmonic, is at- 

 tained. How nearly the critical arrangement is 

 approximated to, may be judged by counting the 

 number of vibrations executed from starting to the 

 first maximum, from the first maximum to the 

 first minimum, and so on the numbers being 

 greater the nearer the adjustment is to the critical 

 condition. 1 made these experiments first on 

 board the Great Eastern during her last summer's 

 cruise ; and it was curious, as an illustration of the 

 general principle of the superposition of motions, 

 to watch the various phenomena of vibration which 



