328 



WRITINGS OF JOSEPH HENRY. 



[1855- 



too complex, even for the highest powers of mathematics, 

 for bodies of less regular forms than those generated by the 

 revolution of simple curves. 



Electrical Induction. — The attraction and repulsion of elec- 

 tricity, like those of magnetism, act at great distances, and 

 produce phenomena which it is necessary clearly to under- 

 stand in order properly to comprehend the explanation of 

 many of the facts connected with atmospheric electricity. 



For the exhibition of these phenomena, which are classi- 

 fied under the name of inductive effects, we may make use 



Fig. 8. 



of the arrangement represented in Fig. 8, in which A is a 

 metallic globe suspended in free air by a fine silk thread, and 



