( 240 ) 



difference bet^Yeell rev and tlie measured value of c[, in the seventh 

 column the value of c m — '— and in the last column the algebraic 



sum of the values of the sixth and seventh colunms. 



If our measurements had an absolute precision the values of the 

 last column would all be = 0. 



In the calculation of the tables IX and X, the correction has been 

 neglected which must be applied if a scale division along an absciss 

 is not equal to a scale division along an ordinate. Thus we assumed 

 that the net of square millimetres consists of real squares or in other 

 words that d^=\.. This has no influence on the calculated value of 

 rev, since the correction of r compensates that of r; but it has an 



tg^i — tgu 



influence on the values of 



^ 



But the differences are not of 



such an order of magnitude that the correction would be necessary ; 

 the general form of the curve remains mialtered. 



The results of the measurements and calculations which are given 

 in figures in the preceding table IX, can be illustrated by means of 

 a diagram. In fig. 3 which corresponds to table IX, the net of square 

 millimetres is represented at about twice its natural_size. A scale 

 division along an absciss =2ö; a scale division along an ordinate 

 = 1,87 X iO-9 Ampère. 



Fig. 3 



Siring N". 10, Photogram A 22, Tables IX and X. 

 Absciss 1 scale division =27; ordinate 1 scale division =1,87X10^'' Amp. 



