ELECTRICAL STANDARDS 187 



international standards throughout the world. Thus 

 the foundations of the science of electrical measure- 

 ment had been truly laid by the committee. Trade 

 and manufacture extend over the world, and the 

 advantages of an international system of units are 

 incalculable. 



About 1891 Viriamu Jones interested himself in 

 the work, and along with Ayrton in 1897 designed a 

 new apparatus for carrying out by the method of 

 Lorenz, used by Rayleigh, a determination of the 

 ohm. The same two members brought forward in 

 1898 proposals for a modified form of ampere balance 

 for measurement of electric current, and were asked 

 to proceed with the construction of an instrument. 

 Viriamu Jones' illness and death prevented the 

 realisation of this plan, and the balance as designed 

 by them with the assistance of Professor Mather was 

 erected in 1906 at the National Physical Laboratory 

 under the supervision of Mr. F. E. Smith. Soon 

 after the death of Viriamu Jones the Drapers' 

 Company offered to find the funds for the erection 

 in his memory of an improved Lorenz apparatus at 

 the National Physical Laboratory. Work on the 

 ampere balance delayed this, but with generous 

 assistance from Messrs. Armstrong, Whitworth & Co. 

 the instrument was ultimately erected to the design 

 of Mr. F. E. Smith, and a full description of it and 

 of the results obtained from its use appears in the 

 Philosophical Transactions for 1914. We now are 

 able to realise the electrical units as defined by the 

 committee in 1862 to a few parts in a hundred 

 thousand. 



The care of the national standards and the 

 issue of certificates of accuracy for standards are 



