622 



LENZ ON ELECTRO-MAGNETISM. 



Copper and 

 iron spirals 



Copper and 

 platina spirals 



Copper and 

 brass spirals. 



Angle of deviation. 



Copper spir. on the ar- 1 

 mature / 



1 Iron spirals -j 



l^ Copper spirals 



r Copper spir. on the ar- "I 

 mature J 



) Platina spirals < 



(_ Copper spirals 



f Brass spir. on the ar- "I 

 mature J 



I Copper spirals < 



[^ Brass spirals 



17-3 



17-3 

 17-3 

 17-4 

 15-2 



15-7 

 15-7 

 154 



18'4 



18-5 

 18-4 

 18-4 



17-4 

 17-6 

 17-4 

 17-4 



15-4 



15-4 

 15-4 



15-8 



18-3 



18-2 

 18-2 

 18-3 



17-6 17-7 



17-5 17-9 



17-6 181 



17-8 18-2 



15-8 



15-9 

 15-8 

 15-3 



18-4 

 18-1 

 18-5 

 18-3 



15-8 



15-4 

 15-4 

 15-9 



18-2 



18-3 

 18-4 

 18-3 



Mean, 



17-500 



17-575 

 17-600 

 17-700 



15-550 



15-600 

 15-575 

 15-600 



18-350 



18-275 

 18-375 

 18-325 



If we now combine the single means together and convert the deci- 

 mals of the degrees into minutes, we obtain from this table the follow- 

 ing results : 



Copper spirals, deviation , 

 Iron spirals, ■ . 



Copper spirals, deviation . 



Platina spirals, . 



Copper spirals, deviation . 

 Brass spirals, . 



. a= 17" 36'-0 

 . a'= 17 35-2 

 . a = 15° 34.'-5 

 ,a' = 15 35-2 

 .a = 18° 19'-2 

 . a' = 18 20-2 



Since in this case the resistances remain the same for every pair of 

 observations, our chief equation (A.) gives, when treated as before, the 

 following proportions of the electromotive powers, if we designate them 

 for copper, iron, platina, and brass with x, x', x", x'" : 



^^sin^(8°i3^) 00033, 



x' sin. (8° 4.2'-6) 



•y-«i"-_(2!i2;i) = 0-99912, 

 x" sin. (7° 4.7'-6) 



^^Sin^(9° 9'-6) .gggg^^ 



.r'" sin. (9" 10'-2) 



These three proportions are all of them so near to unity that there will 

 exist no doubt as to the fact, that wires of copper, iron, platina, and 

 brass suffer one and the same electromotive action ; and that I may be 

 allowed to extend the same position by analogy, even to all other me- 

 tals and substances in general, until direct experiments shall have left 

 the matter beyond all doubt. We shall have therefore the law, 



"that the electromotive power which the magnet produces in spirals 



