Table 269. 261 



VARIOUS DETERMINATIONS OF THE VALUE OF THE OHM. 



The legal value of the ohm is the resistance of a column of mercury of uniform cross-section, 

 weighing 14.4521 gms., and having a length of 106.30 cms. This is known as the international 

 ohm. Mercury ohms conforming to these specifications have been prepared in recent years at 

 the Physikalisch-Tcchnische Reichsanstalt and the National Physical Laboratory, and are now 

 being set up at the Bureau of Standards. The wire standards of resistance at the above-named 

 laboratories agree in value to within two parts in looooo. Hence there is a very close agreement 

 in the values of precision resistances calibrated at these laboratories. 



Smithsonian Tables. 



