930 



Voltaic Electricity. Section 4: Ohm's, Kirchhoff's and Joule's Laws. 



No. (V204S 



62048, 62051, 62053, 62054, 61946, 62056, 62057, 62058, 62060. 1:11. 



62048. 1 : 11. 



1 '"Fnmnrr.nn 



62 052. 1 : 8. 



Apparatus after Prof. Ostwald, for Determining the Conductivity of Electrolytes, Figures <i- 

 (Ostwald-Luther, Physikochemische Messungen, 2 nd Edn., p. 395). The apparatus 

 comprises : 



62.048. Thermostat after Ostwald, Figure, vessel with felt insulating jacket, on tripod, 

 with stirrer, mica vanes and gas burner (the old type of regulator is shown in the illu- 

 stration) 3. 15. d 



or 



62.049. Thermostat after Ostwald, with cord pulley for motor drive 3.12.d 



62.050. Thermometer, 60 C. graduated in 0.1 0. 8. 



62.051. Measuring Wire after Ostwald, with platinum-iridium wire, old pattern 1. in. d 



62.052. - - idem, most recent pattern, Figure 1. 12. 



62.053. Conductivity Vessel after Ostwald, Figure 1. 5.0 



62,05-1. Holder for above, for thermostat use 0. 10. 



61,946. Precision Rheostat with 14 plugs, 11000 ohms, total 2111 ohms 8. d. 



62.056. Induction Apparatus, Figure, for producing buzzing sound, with adjust ing re- 

 sistance, thus rendering the tone minimum more sensitive 1. Id. d 



62.057. Telephone Receiver with antiphone*, round pattern d. 12. d 



<i2,o5s. Current Key 0. 6. 



62.059. Measuring Accumulator d. id. d 



62.060. Connecting Lead with connecting ends d. 12. d 



* An antiphone is a small piece of rubber for inserting in one ear while holding the telephone 

 to tin- other; it holds off any external sound. 



