1895.] on the Absolute Measurement of Electrical Besistance. 621 



done if we are to be guarded against the perpetual inconvenience of 

 unknown possible changes in the coil, the resistance of which is now 

 the legal unit. 



Such a step would have collateral advantages. It would enable the 

 Board of Trade to certify standards of low electrical resistance. With 

 such a machine standards of from a thousandth to a two-hundred- 

 thousandth of an ohm may be measured to nearly the same percentage 

 accuracy. All we have to do in dealing with the very low resistances 

 is to pass a sufficiently large current through them, and shunt the 

 standard coil of the machine. But to enter into details on this 

 point would lead me too far. I must content myself with saying 

 that I believe such a machine is much the best instrument for 

 standardising low electrical resistances, and that accurate standards 

 of low resistance would be of great service both in the laboratory 

 and the workshop. 



I have, in conclusion, only to express my obligation to my assistant, 

 Mr. Samuel Harrison, for the great and constant help he has given me 

 in the course of my investigations on this subject. 



[J. V. J.] 



