ON STANDARDS FOR USE IN ELECTRIC.A.L MEASUREMENTS. 



00 



Report of the Committee, consisting of Professor Gr. Carey Foster, 

 Sir William Thomson, Professor Ayrton, Professor J. Perry, 

 Professor W. Gr. Adams, Lord Kayleigh, Dr. 0. J. Lodge, Dr. 

 John Hopkinson, Dr. A. Muirhead, Mr. W. H. Preece, Mr. 

 Herbert Taylor, Professor Everett, Professor Schuster, Dr. 

 J. A. Fleming, Professor Gr. F. Fitzgerald, Mr. R. T. GtLAZe- 

 BROOK (Secretary), Professor Chrystal, Mr. H. Tomlinson, Pro- 

 fessor W. Gtarnett, Professor J. J. Thomson, Mr. W. N. Shaw, 

 Mr. J. T. BoTTOMLEY, and IVIr. T. GtRAY, appoi^tted for the 

 purpose of constructing and issuing Practical Standards for 

 use in Electrical Measurements. 



[Plate I.] 



The Committee report that the work of testing resistarce coils has 

 been continued at the Cavendish Laboratory, and a table of the values 

 found for the various coils is given. 



B.A. Units. 



In conformity with the opinion expressed by the Committee in their 

 last report some steps have been taken towards the construction of an 

 air-condenser. 



A meeting was held in London and Dr. Alex. Muirhead exhibited 

 an air-condenser, capacity about 'OOSS mf. This condenser consist.s 

 of a series of concentric cylinders of brass insulated from each other by 

 glass rods. 



Dr. Muirhead expressed his willingness to lend this condenser to 

 the Committee with two others of similar construction, and it was agreeil 

 that the Secretary should be requested to test them and to make a 

 determination of their absolute capacity. Some delay in sending the 

 instruments to Cambridge unavoidably took place, but the experiments 

 requisite are now in progress ; so far, of the 80Z. granted last year for the 

 purpose only 21. 10s. has been expended. 



During the year the original resistance standards of the Association 



