495 



strip (S), which is about 6 mm. in width, is fastened by means of a small 

 screw at (F). To this strip the gold leaf is fastened by means of wax 

 or shellac. The rod (D) is terminated at its lower end by means of a 



Fig. 4. 



disk (A), which is 8 cm. in diameter. This disk is screwed onto the end 

 of (D), and larger or smaller disks may be used, thereby varying the 

 capacity of the electroscope. Supported upon a screw (T) which passes 

 through the bottom of the iouisation chamber is a disk (B) the same 



