820 



LENZ ON THE VARIOUS COVDUCTING. POWERS 



Now by solving these equations with regard to x and 3/ according to 

 the method of the least squares, we shall obtain 



X = 12-5386 1/ — 8-7508 



If we substitute these values in the equations (A) and ascertain from them 

 the values a, a', a", or sin (^ a^), sin (i a^ , y), sin (1 a^ , j^), we shall 



obtain the angles ^a^, ^a^,^, ^a^, 14, and multiplying them by 2 



we shall find out the angles of the seventh column. 



The very slight diiFerences of the values indicated in the 8th column 

 from those observed, convince us that the hypothesis which is the base 

 of the calculation is correct, and that therefore the resistances of (he 

 tvi7'es are in a direct ratio, and their conductibilities in an inverse ratio 

 to their lengths. 



I performed a short time previously another series of experiments, 

 and diminished the electromotive spiral by two coils without shorten- 

 ing its length or altering its resistance. The results are contained in 

 the following table : 



Angles of Deviation. 



4. Average. 



(at the beginning of the 

 experiment , 

 at the end of it. ... | 



With interposed wire 7 feet long 



14 



21 



28 



35 



77-9 

 77-3 

 77-3 

 47-6 

 34-8 

 27-4 

 22-5 

 19-4 



«1-1 

 80-2 

 80-2 

 48-7 

 35-0 

 27-7 

 23-3 

 18-8 



81-7 

 81-3 

 81-2 

 49-9 

 36-6 

 28-4 

 23-4 

 19-8 



81-7 

 80-2 

 79-8 

 49-5 

 35-8 

 28-6 

 22-8 

 19-3 



80-6 



79-69 



48-92 

 35-55 

 28-02 

 23-00 

 19-32 



We perceive by the deviations which occurred at the beginning and 

 end of the series of experiments, performed without inserting the wires 

 between the spiral and the wire of the multiplier, that the power of the 

 magnet was a little diminished during the experiment. This induced 

 me, therefore, before the calculation of the results of the experiment, 

 to make a slight correction of the angles of deviation, founded on the 

 principle that the diminution of power was proportional to the time, 

 and that the observations with various lengths of wire followed 

 each other at equal intervals, which was nearly the case. I repre- 

 sented the angle of deviation when no wires were interposed at the 

 beginning of the experiment by a^, and at the end of it by a,-, and 



found 



5«.i- = (1 + in)m\ (^ «(,,)) ; 



