86 POPULAR LECTURES AND ADDRESSES. 



before the definitive practical adoption of the 

 absolute system by France, Germany, and other 

 European countries, as decreed' by the Inter- 

 national Conference for the determination of 

 electric units, held at Paris in October 1882. 

 The decision adopted was, not to take the 

 British Association unit Doubt was thrown 

 upon its accuracy, which we shall see was well 

 founded. The question of a strict foundation 

 for a metrical system was before the Conference, 

 and it was inclined to adopt the absolute system, 

 but the question occurred " What is the ohm ? " 

 Who can see an ohm ? Who can show what an ohm 

 is ? Who can measure the resistance of any con- 

 ductor for us, in this absolute measure of Weber's ? 

 Weber's own measurement differed greatly from 

 that of the British Association. Several experi- 

 menters, in endeavouring to verify or test the 

 British Association measurement arrived at results 

 which were discordant among themselves, and 

 therefore could not be confirmatory of the British 

 Association measurement. Things were in this 

 doubtful state, and the Conference had a very im- 



