F. Dellmann on Atmospheric Electricity. 



403 



directed arm of this lever has at its top a horizontal broader 

 part, about l\ inch in length, slightly bent around the rod. 

 The crooked lever is 

 80 fastened into the 

 rod by a pivot, that, 

 after the handle be- 

 low has been pulled 

 at, it falls back by its 

 own gravity. The 

 lower arm of the le- 

 ver, from one side of 

 which the descending 

 wire hangs, is flat and 

 about 1 inch broad, 

 so as to move safely 

 and easily in the slit 

 of the rod. On the 

 top of the rod is fixed 

 a copper box /, with a 

 partition in the mid- 

 dle which separates 

 the lower half, de- 

 stined to fit on to the 

 rod, from the upper, 

 into which is fixed 

 the carrier m of the 

 collecting sphere n. 

 This carrier m has a 

 shell-lac foot resting 

 on a thick plate of 

 caoutchouc, and at 

 about 5 inches from 

 its lower extremity is 

 surroundedbyathick 

 ring of shell-lac, upon 

 which sits a thick 

 caoutchouc ring ; so 

 that by meansof these 

 two contrivances it 

 stands insulated in its box, and can be struck with the crooked 

 lever k without danger of breaking off the shell-lac. This shell- 

 lac is everywhere as smooth and polished as possible, so as to 

 admit of being conveniently and carefully freed from dust and 

 moisture. The copper collecting sphere n, 6 inches in diameter, 

 is fastened to the carrier m by means of a screw. The box, and 

 with it the sphere, can easily be withdrawn from, and replaced 

 2D 2 



