ELECTRICAL UNITS OF MEASUREMENT. 121 



consistent, and the dimensions of all your in- 

 struments and apparatus must all be all reckoned 

 uniformly in terms of the unit of length adopted 

 in the absolute definition. The ohm is 1,000,000,000 

 centimetres, or 10,000 kilometres, per second. If 

 we are to make the ohm an absolute electro- 

 magnetic unit with the second as the unit of 

 time, we must take the earth's quadrant as the 

 unit of length. If we take that consistently 

 throughout, we need never leave this particular 

 system and we need have nothing to do with 

 C.G.S. We should have the Q.G.S. system pure 

 and simple ! But it would be obviously incon- 

 venient to measure the dimensions of instruments, 

 the diameters of wheels, and the gauges of wire 

 in submultiples of the earth's quadrant. Imagine 

 the horror of a practical workman, on hearing a 

 scientific person say to him, " Give me a wire 

 1/100,000 of an earth-quadrant long, and 

 1/10,000,000,000 in diameter." Now wherein does 

 the so-called practical system differ from the 

 absolute system, and why is it not to be as logical 

 and complete as the absolute system ? We would 



