MECHANICAL ELECTRICITY 285 



Exp. 25. The Bismuth disc and an antimony 

 rod gave a current of 45° in the usual direction 

 for Bismuth — the antimony robbing the Bismuth. 

 Antimony positive : Bismuth negative, 



Exp. 26. Silver with Bismuth 40'. The usual 

 Bismuth current. 



Exp. 27. Gold with Bismuth 35^ The usual 

 Bismuth current. 



Exp. 28. Lead with Bismuth 271°. The usual 

 Bismuth current from the lead to the Bismuth. 



Exp. 29- With an iron disc, rotating under 

 similar conditions, I obtained, by a turning tool of 

 steel, a current of 10°, Jrom the iron towards the 

 tool. 



I tested the galvanometer by a voltaic pair, to 

 see the direction of the current, and found the 

 direction as stated to correspond. 



I repeated afterwards the same experiment, by 

 steam power, with a much larger cylinder of cast 

 iron, apparently harder than before, and the 

 needle vibrated from 15° to 30°, stationary at 



