174 ELEMENTS OF STATIC ELECTRICITY. 



those already described; the replenisher, gauge, and 

 Leyden jar, being omitted; also the bifilar attachment 

 in the quadrant instrument; the movements of the 

 needle being controlled by the torsion of a fine wire. 

 And, in the attracted-disc electrometer, the position of 

 the discs is sometimes reversed; the attracting disc 

 being placed above, in the portable style. 



