MAWSON & SWAN, 



DISCHARGERS. 



Single Discharger, 3 - 



Jointed Dischargers, 5 - 



Do. do. with two handles, 8 6 



Henley's Universal (Fig. 76), with table and press, 9/- and 18 -; 

 with insulated handles, pair of carbon holders, and pair of 

 forceps for holding fine wires, 257-; larger size, 4o/- 



ELECTROMETERS or ELECTROSCOPES. 



Henley's Quadrant, a useful instrument, to measure the force of 



accumulated electricity in electrical jars and batteries, 36 

 The same, better finished, ivory arc, &c., 7/6 

 Lane's Discharging Electrometer, 5/-; larger, 7/6 

 Bennett's Gold Leaf Electroscope, for showing minute quantities 



of electricity, 7.6 and 12 6 

 The same, large size, superior make, 21 - 

 Volta's Condensing Electroscope (Fig. 77), with 6-in. condenser 



and glass handle, 27;-; smaller size, 16 - 



FIG. 77. FIG. 78. 



Coulomb's Torsion Electrometer (Fig. 78), for accurate measure- 

 ment, ^ 3 s. ^^ 



13 and 15, Mosley-street, Newcastle-on-Tyne. 



