ELECTRICAL UNITS OF MEASUREMENT. 1 29 



say that mho is the word to be used, but I wish 

 it could be accepted, so that we might have it 

 at once in general use. We shall have a word 

 for it when we have the thing, or rather, I 

 should say, we shall have the thing when 

 we have the word. The Appendix to 

 the 1862 Report of the first British Association 

 Committee on Electric Measurements contains a 

 description of a " Resistance Measurer " invented 

 by Sir William Siemens, and of a " Modification 

 of Siemens' Resistance Measurer," by Professor 

 Fleeming Jenkin. This instrument gives directly 

 the resistance of a conductor, by means of an 

 instrumental adjustment, bringing a magnetic 

 needle to a zero position for each observation. In 

 the original Siemens instrument the adjustment 

 is a shifting of two coils by translational motion, 

 and the conductivity is read on a scale of equal 

 divisions adapted, by means of a curve determined 

 by experiment, to give a reading of the required 

 resistance. In Jenkin's modification the mechanical 

 arrangement is much simplified by the adoption 

 of a different electro-magnetic combination ; and 



K 



