NOTES AND APPENDICES. 



305 



It will be seen that this intensity, at first very feeble, in- 

 creases afterwards in a nearly regular manner for total resist- 

 ances varying between twice and four times the total resist- 

 ance of the machine. These intensities have been calculated 

 by the formula 



.9* 



is C } &9 10 ohmt 



in which Q is the intensity in webers, E the electro-motive* 

 force in volts, R the total resistance in ohms. 



Work transformed into Electricity. The figures we have- 

 found are referred to the unit of time, the second. The 

 value of the work transformed into electricity is expressed 

 by Joule's formula, w - 10 Q'-* R, in which Q and R have the 

 same meaning as before, and w is the work in meg-ergs. In 



20 



