452 



Mr. J. D. Hamilton Dickson on 

 Table II. 



(1) 



(2) 



(3) 



(4) 



(5) 



(6) 



14 



57-935 



624-2 



62413 



+ •07 



0049 



31 



56-56 



599-8 



59940 



+ •40 



•16 



24 



52-795 



532-2 



532-58 



-•38 



•1444 



30 



47-52 



440-9 



44113 



-•23 



•0529 



12 



44-62 



3918 



391-93 



-13 



•0169 



6 



4277 



360-9 



360-95 



-•05 



•0025 



mean 













of 9, 10 



36-47 



257-5 



257-78 



-•28 



•0784 



mean 













of 35, 36 



34-66 



229-3 



228-81 



+•49 



•2401 





26 345 



100-0 



99-55 



+ •45 



•2025 





19671 



o-o 



•35 



-•35 



•1225 



This formula is 



(R + 140-1185) 2 =21-951052(* + 1162-813), . . (10) 



which gives, for the resistances observed, the temperatures 

 calculated in column 4. The 5th column gives the excess, v y 

 of the temperature observed over the temperature calculated ; 

 and the 6th column contains v 2 , whence the probable diver- 

 gence between an observed and a calculated temperature is 



r 2(f 



•6745 



S 



= •23, 



or a little over a fifth of a degree on temperatures ranging 

 over 600° — a degree of closeness quite comparable with the 

 observations themselves. 



This formula gives for the absolute zero (R=0) the tem- 

 perature -268°-4 C. 



Observations of Profs. Dewar and Fleming* . — Profs. Dewar 

 and Fleming have investigated the alteration of the resist- 

 ance of various metals at low temperatures ; and among these 

 they give their observations of the alteration of the resistance 

 of a certain platinum wire with alteration of temperature. 

 In view of their later researches on the properties of matter 

 at low temperatures, and in those cases where they record 

 careful numerical results in terms of platinum-temperatures, 

 it is of much importance to knowf that this wire is the 

 actual piece of wire forming the platinum-thermometer after- 

 wards referred to by them as " ¥". 



* Phil. Mag. 1893, vol. xxxvi. p. 282. 



t I am indebted for this information to Messrs. Petavel and Morris, 

 who so ably assisted them in these researches. 



