No. 61 836. 



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



911 



108 OHM 



' SILBER 



KUPFER 



UStN 



NEUSIIBER 



COHSTANSTAN 



61 833. 1 : 8. 



61835. 1:11. 



Ammeters : 



61810 

 61811 



61812 

 61813 

 61814 

 61815 



I 

 5 



1 



2.5 

 5 

 10 



With 1 Range 



0.01 

 0.05 



With 2 Eanges 



2 0.01 



5 0.025 



10 0.05 



20 



0.1 



0.02 

 0.05 

 0.1 

 0.2 



10. 10. 

 10. 10. 



12. 5. 



12. 5. 



12. 5. 



12. 5. 



60,118. Precision Compass for determining the direction of current in leads and the poles d. 

 in magnetic fields, Fig. 60,118, p. 792 0. 12. 



The instrument is closed on both sides by watch glasses in order to render the magnet needle always 

 visible. The magnet needle itself is very light, thoroughly well balanced, and rests in stones. As the in- 

 strument always gives a plain deflection when brought into the immediate neighbourhood of a conductor 

 traversed by a current of 0.1 ampere, it is consequently possible to ascertain the direction of flow of 

 currents in conductors. 



Section 4: Ohm's, Kirch hoff's and Joule's Laws. 



3. Apparatus for Fundamental Resistance Experiments, Figure, comprising 5 wires 

 of 1 m length stretched between clamps on a polished board. The resistance of each 

 wire can be measured singly. The wires are: 3 Manganin wires of 2, 1 and 0.5 mm; 

 1 Iron wire of 0.5 nun and 1 Silver wire of 0.5 mm diameter 



U1.X34. -- idem, after Weinhold (W. D., p. 782 [723]), on board with terminals 



1. 0. 

 1. 0. 



<>l,x.;r>. 5 Wires of Constantan, German Silver, Iron, Copper and Silver, Figure, of same 

 thickness and same resistance, the lengths corresponding to the specific resistance; on 

 hoard with pole terminals 1. 0. 



61,836. 4 Wires of Copper, Brass, Iron and Manganin, of same length and same cross section. 



in glass vessel for filling with paraffin, for determining specific resistance (M. T. Fig. 198) 1. 4. 



01. -'(. 18, 2459. 



