INFLUENCE OF SUSPENSION ON WATCH. 385 



would gain or lose by the oscillation ; and it 

 is therefore better for good time-keeping to 

 have a massive watch-case than a light one. 

 No doubt, the rate of an ordinary watch-chrono- 

 meter is very much affected by railway travelling. 

 His own pocket-watch gained from four to eight 

 seconds in journeys to London and back. The 

 railway carriage vibration affected as a prime 

 mover the vibration of the balance-wheel, not 

 merely as vibrations induced in the frame by the 

 interior movement would do. If a chronometer 

 case is well weighted, its performance will not be 

 practically injured by the influence which has been 

 described. If it were firmly attached to the 

 middle of a two-feet-long plank, with heavy 

 weights fixed on it near the ends, its rate would 

 be sensibly the same as if its case were absolutely 

 fixed, however this board is supported. To avoid 

 damage from the tremors of the ship, this board 

 should be placed on cushions, and strapped down, 

 or lashed properly, for security. 



If a watch be hung on a nail, it depends upon 

 the dimensions of the watch and the time of the 



VOL. II. C C 



