

OF THE NATIONAL PHYSICAL LABORATORY. 373 



Second Set of Comparisons. April and May, 1903. 



millims. 



Mean ice-point of gas thermometer before comparisons . . . . 180'92 3 

 ,, after .... 182'66 



Mean value of a from determinations before comparisons = '003670, 

 after = '003671. 



v = -01( V 



v o 



In this case there is a change in the zero-point greater than that observed in the 

 first set and in the opposite direction. In allowing for this, the change was supposed 

 to have been proportional to the time. 



Platinum thermometer BA 2 : 



R = 2 '572 51 ohms before commencing comparisons, 

 = 2'57198 at conclusion of ,, 



F.I. = 1 '00008 before commencing ,, 



= 1 '00000 at conclusion of ,, 



8 = 1*491 mean of large number of observations extending over six months. 



The platinum thermometer constants of this set are expressed in terms of a slightly 

 different unit from that employed in first set six months earlier. 



