( 245 ) 



Ui' diagram ]'e(iiiiie no nearer explanalion since lliev arc in every 

 respect analogons lo tliose of siring n". JO lliat were discnssed above. 

 We have liere again 1"=: 500 lience 1 mm. absciss = 2(7. Fui-lher 

 c == 582, 80 1 mm. ordinate = 1.72 X iO"-' Amj). Tiie value ol" ni 

 has been put diii-ing tlie liist 5 thousandths of a second at 0.037 

 which is rather more tlian JO times the vabie found in ciiapter 3. 

 At t= Go and t=7o-, )n has no iniluence. Beginning witli t = Sn, 

 lu lias been taJven into account again, tliis time willi a vahic of 

 0.00688 or ratlier more than 1.9 times the value of ciiapter 3. 



Some other curves, also recorded witli a sensitive position of the 

 galvanometer show after analysis diagrams that agree completely 

 with the two above described diagrams 3 and 4. So they require 

 no nearer elucidation here. 



We will not omit, however, to give the results of the analysis of 

 a curve recorded with a less sensitive position of tiie galvanometer. 

 The numbers are collected in tables XIII and XIV, which lilve the 

 corresponding diagram 5 liave been arranged in the same manner 

 as the preceding tables and diagram. They represent a curve written 

 by string 14, with 1 megohm in the galvanometer circuit. Here we 

 have c = 115,2, hence ordinate 1 mm. := 8.07 X ^^~'* Amp., while 

 absciss 1 mm. is again = 2 d. 



The \alue of m can be kept constant here at a value which is 

 1.45 times greater than the value which would liold for strong 

 tension of the string. 



We see that most of the examined points are calculated w^ith an 

 error, smaller than 1 mm. and that the correction is already pretty 

 accurate after 1(7. After la the error amounts to 1.4 on a total 

 deflection of 30.6 mm., i. e. 4.6 "/„. This proves that by means of 

 analysis of the curve with a sensitiveness of the galvanometer 

 c = 1152, for wdiicii 1 mm. deflection corresponds to a current of 

 8.67 X'J-^""^ Amp., the real intensities of the current can be known 

 beginning at 1 <J after starting the current, and then progressing 

 0.5 o each time. 



In all probability these times can still be materially shortened 

 when the speed of the photographic plate is increased. With the 

 curves mentioned in this paper a speed of the sliding frame of 

 500 mm. per second has chiefly been used, but it is evident that 

 with improved mechanical appliances it Avill be possible to attain 

 greater speeds. We have lately succeeded in obtaining very regular 

 speeds of 1 M. per second. 



At the end of this chapter we remind the reader that an analysis 

 of the curves is only necessary when it is desired to measure xevy 



