No. 62113. 



Condensers. Determination of Capacity. 



935 



62 103 62 108. 1 : 9. 



62,101. Double Commutator, Figure, after Ayrton and Perry (Elektrot. Ztschr., 1889, 

 p. 412), for measuring capacities and coefficients of self induction and of mutual induction 

 by means of the Wheatstone Bridge; on board with 110 volt D. C. motor, tachometer, 

 regulating resistances for securing wide degree of regulation, stepped pulley, switch, 

 plug contact with plug and 2 metres flexible 16. 0. 



The measurements can be made with much more certainty with the aid of a mirror galvanometer 

 than with a telephone. 



<>2,102. - - i (1 e m, built into a table, Figure. On the table are placed the arrangement 

 for measuring insulation resistances as well as various instruments for measuring capa- 

 cities and coefficients of induction . . :27. 0. 



In addition to showing the apparatus mentioned under No. 62,101, the Figure illustrates the switch, 

 plug boxes, 6 terminals, 1 motor switch. 1 key (all fitted to ebonite slabs), fixed on to the table-top; these 

 articles are included in above price. Not included in the price are: the Plug Rheostat, the Cells, and the 

 Galvanometer Shunt. The resistance coils of the precision rheostat should be wound so as to be non- 

 inductive and anti-capacity (Chaperon's method). As a suitable Mirror Galvanometer we can recommend '. 

 our Galvanometer No. 61,407, with Reading Device No. 61,409 for fitting to the ceiling. 



Apparatus for determining Dielectric Constants, chiefly of Liquids, after Nernst (Kohlrausch, 

 Praktisehe Physik, 10 lh Edn., p. 575), Figure, comprising: 



62.103. String Induction Coil with shunt liquid resistances j 1. 12. 



62.104. 2 Measuring Condensers with shunt liquids resistances 6. 10. 



62.105. Testing Condenser for the liquid to be tested 0. 9. 



62.106. Round Pattern Telephone with antiphone* 0. 9. 



62.107. Thermometer 0. 3. 



62.108. Connecting Flexibles 0. 2. 



Apparatus for determining Dielectric Constants of Solids, for demonstration purposes, after 

 Grimsehl (Ztschr. f. d. phys. u. chem. U. 16, 1903, p. 21), consisting of: 



62.109. Condenser with 3 Plates, the centre one being fixed and the two outer ones movable, 



with arrangement for carrying the plates which are to be inserted and tested ... 2. 5. 



62,103. String Induction Coil with liquid shunt resistances 1.12.0 



62,106. Round Pattern Telephone with antiphone * 0. 9. 



2.112. Dry Cell 0. 3.0 



In place of No. 62,103 a small electric machine can be used, in which case the shunt 

 resistances are formed of. 



62,113. 2 Glow Lamps with Holders, mounted on slate j 0. 6. 



* See note on p. 930. c| 52 ., 7 



