EEPOKTS 



ON THE 



STATE OF SCIENCE. 



Experhncids for improving the Gondrudion of Vractlcal Standardf; for 

 Electrical Measuremont!^. — Report of the Committee, coihsistincj 

 o/Lord Kayleigh (GhaiTinan), Dr. R. T. Glazerrook (Secretary), 

 Lord KELvm, Professoi-s W. E. Ayrton, J. Perry, W. G. 

 Adams, and G. Carey Foster, Sir Oliver J. Lodge. Dr. A. 

 MuiRHEAD, Sir W. H. Preece, Professors J. D. Everett, A. 

 Schuster. J. A. Fleming, and -T. J. Thomson, Dr. W. X. Shaw, 

 Dr. J. T. Bottomley, Rev. T. C. Fitzpatrick, Dr. G. Johnstone 

 Stoney, Professor S. P. Thompson, Mr. J. RenniE; Mr. E. H. 

 Griffiths, Sir A. W. Rucker, Professor H. L. Callendar, 

 Sir W. C. Roberts-Austen, and Mr. George Matthey. 



Appendix. — OntheBefini-tionoftheV'iutoflleat 55 



DuRiXG the past year the apparatus belonging to the Association has been 

 removed to and set up at the National Physical Laboratory at Bushy 

 House. A room in the basement has been fitted for accurate resistance 

 work. By means of a thermostat the temperature can be kept under very 

 complete control, and the room has proved most suitable for its purpose. 

 In it the resistance standards of the Association liave been set up, and a 

 number of comparisons have been made by Mr. F. E Smith. Particulars 

 as to the results of these comparisons can best be given at a later date, 

 when the mercury standards now in course of construction have been 

 set up. 



The work of setting up the mercury standards of resistance has been 

 further advanced. A number of tubes, both of verre dur and of Jena 

 glass, 16'", have been calibrated by Mr. Smith. When the final corrections 

 to the weights used have been obtained from the Bureau International it 

 will be possible to complete these and to determine the values of the 

 platinum -silver and manganin standards in terms of the mercury unit. 



From the resistance-room a cellar — formerly the wine-cellar of Bushy 

 House — opens, and in it work requiring an extreme constancy of tem- 

 perature can be carried on. 



In this room Mr. Smith has set up a number both of Clark and also 

 of Weston cells, and comparisons between these have been carried on 

 systematically. 



Discrepancies of a considerable amount have been found between cells 



