42 REPORTS ON THE STATE OP SCIENCE. 



coil of insulated wire forming part of the aforesaid instrument and 

 connected to the aforesaid terminals is in all parts at a temperature 

 of 16°-4 C. 



' II. Standard of Electrical Current. 



' A standard of electrical current denominated one v\.mpere agreeing 

 in value within the limits of accuracy aforesaid with that of the Inter- 

 national Ampere and being the current which is passing in and through 

 the coils of wire forming part of the instrument marked " Board of 

 Trade Ampere Standard Verified, 1894 and 1909," when on reversing 

 the current in the fixed coils the change in the forces acting upon 

 the suspended coil in its sighted position is exactly balanced by the 

 force exerted by gravity in Westminster upon the iridioplatinum weight 

 marked A and forming part of the said instrument. 



' III. Standard of Electrical Pressure. 



' A standard of electrical pressure denominated one Volt agreeing 

 in value within the limits of accuracy aforesaid with that of the Inter- 

 national Volt and being one hundredth part of the pressure which when 

 applied between the terminals forming part of the instrument marked 

 " Board of Trade Volt Standard Verified, 1894 and 1909," causes that 

 rotation of the suspended portion of the instrument which is exactly 

 measured by the coincidence of the sighting wire with the image of the 

 fiducial mark A before and after application of the pressure and with 

 that of the fiducial mark B during the application of the pressure, these 

 images being produced by the suspended mirror and observed by means 

 of the eyepiece. 



' In the use of the above standards the limits of accuracy attainable 

 are as follows : — 



' For the Ohm, within one hundredth part of one per cent. 



' For the Ampere, within one tenth part of one per cent. 



' For the Volt, within one tenth part of one per cent. 



' The coils and instruments referred to in this Schedule are deposited 

 at the Board of Trade Standardising Laboratory, 8 Richmond Terrace, 

 Whitehall, London.' 



Establishing a Solar Observatory in Australia. — Report of the Committee, 

 consisting of Sir David Gill (Chairman), Dr. W. G. Duffield 

 (Secretary), Dr. W. J. S. Lockyer, Mr. F. McClean, and 

 Professors A. Schuster and H. H. Turner. 



During the past year the movement for the establishment in Australia 

 of a solar observatory has made considerable progress, the annual 

 upkeep having been promised by the Commonwealth Government pro- 

 vided that a sum of 10.000L be forthcoming from private sources for its 

 erection and equipment. 



The Secretary was in Australia during the early part of the year 

 1909-10, and he has already reported 1 the formation of the Solar 



1 Winnipeg Report, 1909. 



