154 



REPORT 1898. 



previously determined we have four measurements of resistance, as 

 follows: — 



A. Mr. Glazebrook in March, 1894. 



B. Board of Trade in Nov., 1896. 



C. Board of Trade in Aug., 1897. 



D. Mr. Glazebrook in Dec, 1897. 



Resistance = 9-9923 ohms at 14-8° C. 

 = 9-992994 „ 1486° C. 



= 1000712 „ 19-3° C. 



= 9-9901 „ 13-9° C. 



These furnish data for calculating the temperature coefficient, and we 

 have also the value given by the makers, Messrs. Nalder Bros. & Co. : — 



This table shows that the coefficients calculated from tests B and C 



Fig. 5. 



Excess res /staff ce in ofims 



/* /S /S /7 /B /$ 20 V 22 13 2* 2i 26 27 



TemfiergCurei/> 'C 



Curve showing change of resistance of 10-ohm standard coil, No. 3873, with change 

 of temperature. Ordinates give excess of resistance of 3873 above 3874 at 16-70° C. 



and from tests D and C are both in very close agreement with those I 

 obtain for the same range of temperature. 



Ten-Ohm Standard CoU, No. 3874. 

 A series of tests on coil No. 3874, lasting from May 19 to May 31, 



