342 THE CANADIAN NATURALCST. [Vol. X. 



siderinQ" that in scientific work metrical measure is now almost 

 universally adopted, and that its use has been alread}' legalised 

 in this country, I venture to hope that its universal adoption for 

 commercial purposes will soon follow as a matter of course. The 

 practical advantages of such a measure to the trade of this coun- 

 try would, I am convinced, be very great, for English goods, 

 such as machinery or metal rolled to current sections, are now 

 almost excluded from the Continental market, owing to the unit 

 measure employed in their production. The principal impedi- 

 ment to the adoption of the metre consists in the strange anomaly 

 that althouo'h it is leoal to use that measure in commerce, and 

 although a copy of the standard metre is kept in the Standards' 

 Department of the Board of Trade, it is impossible to procure 

 legalised rods representing it, and to use a non-legalised copy of 

 a standard in commerce is deemed fraudulent. Would it not bo 

 desirable that the British Association should endeavor to bring 

 about the use in this country of the metre and kilogramme, and, 

 as a preliminary step, petition the Government to be represented 

 on the International Metrical Comujission, whose admirable 

 establishment at Sevres possesses, independently of its practical 

 work, considerable scientific interest, as a well found laboratory 

 for developing methods of precise measurement. 



Next in importance to accurate measures of length, weight, 

 and time, stand, for the purposes of modern science, those of 

 electricity. 



The remarkably clear lines separating conductors from non- 

 conductors of electricity, and magnetic from non-magnetic sub- 

 stances, enable us to measure electrical quantities and effects 

 with almost mathematical precision ; ;md, although the ultimate 

 nature ol' this, the youngest scientifically investigated form of 

 energy, is yet wrapt in mystery, its laws are the most clearly 

 established, and its measuring instruments (galvanometres, elec- 

 trometers and magnetometers), are amongst the most accurate 

 in physical science. Nor could any branch of science or indus- 

 try be named in which electrical phenomena do not occur, to 

 exercise their direct and important influence. 



If, then, electricity stands foremost amongst the exact sciences, 

 it follows that its unit measures should be determined with the 

 utmost accuracy. Yet, twenty years ago, very little advance 

 had been made towards the adoption of a rational system. Ohm 

 had, it is true, given us the fixed relations existing between 



