ELECTROMAGNETIC EFFECT OF CONVECTION-CURRENTS 265 



deflexion was merely a throw, and that no continuous deflexion was 

 obtained. This is entirely erroneous; there was always a continuous 

 deflexion. The throw was read merely because the needle was always 

 more or less unsteady, and better results could be got by seizing a 

 favorable moment when the needle was quiet and reading the throw, 

 than by attempting to take the successive elongations, or waiting for 

 the needle to come to rest. In the experiment described above the 

 needle was very steady and no such trouble was experienced. On elec- 

 trifying, the needle would take up a certain position and would remain 

 there as long as the charge was kept up ; on reversal, it would move off 

 to a new and perfectly definite position about 6 to 7 mm. away, and 

 remain there, &c. H. A. E. 



C. T. H. 



