ON STANDARDS OF ELECTRICAL RESISTANCE. 15 



brous organization by which their work was commenced. When the Com- 

 mittee was first appointed, no coherent system of units for the measurement 

 of electrical resistance, cm-rents, quantity, capacity, or electromotive force 

 had met with general acceptance. The so-called absolute system existed 

 indeed on paper, but in far too intangible a form to be either understood or 

 used by practical men. At the same time, proposals for the adoption of 

 isolated units, variously determined, had been carried out, with more or less 

 success, so as to meet in some degree the immediate requirements of tele- 

 graphy. Many competing imits of this nature were in the field. The Com- 

 mittee chose a system based on the absolute measure, and so, at least as far 

 as electrical resistance was concerned, made this measurement a tangible and 

 practical operation ; and their choice has been ratified by men of science over 

 a great portion of the globe. Copies of the unit of resistance adopted by 

 the Committee in 1864 were deposited at the Kew Observatory ; and others 

 exist in the hands of electricians in various parts of the world. Comparisons 

 of several of the copies, which were published in the Report of the Committee 

 for 1867, showed that, with one or two exceptions, the ratio of their resist- 

 ances remained unchanged. It is, however, desirable that additional com- 

 parisons should be made from time to time. Incidentally many researches of 

 considerable value were carried out by th^ Members of the Committee; and 

 the yearly reports have been so generally in request that it may be advisable 

 to reprint the entire series. 



No second unit, however, has been issued by the Committee, although 

 apparatus for the determination of the irnits of capacity, quantity, potential, 

 and intensity of current have been constructed, both with the funds of the 

 Association and from the private means of its members. The great numbere 

 of the Committee render meetings of rare occurrence ; and the Subcom- 

 mittees appointed to undertake the work have been lately remiss in its exe- 

 cution ; the Committee, believing that direct responsibility to the Association 

 and greater freedom of action will act as a stimulus to individual members, 

 beg to suggest that the Electrical-Standards Committee be not reappointed, 

 but that three new Committees of smaller numbers be chosen, to determine 

 and issue: — 1st, a condenser representing the unit of capacity; 2nd, a 

 gauge for showing the unit difference of potential ; 3rd, an electrodynamo- 

 meter adapted to measm-e the intensity of currents in a decimal multiple of 

 the absolute measui-e. 



They would also suggest that it be an instruction to each Committee that 

 it shall carry out the system adopted by the Electrical- Standards Committee, 

 and that these new Committees shall have the use of all instruments hitherto 

 constructed with the funds of the Association, a list of which is appended (in 

 account book). 



Considering that the principal instruments have already been constructed, 

 the Committee believe that a small grant of, say, £20 to each Committee, 

 will be sufficient to meet the expenses of the next year. 



In conclusion, should this suggestion be adopted, they beg to recommend 

 •that a volume, containing the complete series of reports, be issued by the Asso- 

 ciation, and sold to the public, feeling assured, from the demand for isolated 

 copies, that such an issue would involve no expense to the Association. 



