to the Lonyitudinal Expansion in Rods of Spring Steel. 45 





 200 





 200 





 200 





 200 







Hence in the mean, 



. . . 

 200 .. . 

 200 .. . 







200 

 200 



and for P = 100 gr. 



X'. 



Y'. 



X". 



Y". 



122-5 



99-6 



33-6 



93-5 



49-1 



170-0 



103-9 



22-3 



121-3 



99-5 



32-5 



93-3 



41-2 



27*7 



97-5 



161-9 



124-5 



99-6 



35-8 



93-5 



50-0 



169-6 



104-7 



21-9 



122-7 



99-0 



34-0 



92-8 



48'6 



27-6 



105-0 



161-8 



122-6 



98-7 



339 



92-6 



> 

 122-72 



99-28 



33-96 



93-14 



49-55 



169-80 



104-30 



22-10 



44-90 



27*65 



101-25 



161*85 



(X'). 



(T). 



(X"). 



(Y"). 



121-71 



97-93 



35-11 



91-77 



48-75 



166 61 



104-39 



21-97 



44-82 



27-50 



102-23 



158-90 



B = 71-56, T = 69-01; 



B = 35-78, T = 34-51. 

 In the following Table I give the values 



of B and T for 



P = 100 gr., as they have subsequently been found; at the same 

 time I will give the temperatures at which the experiments were 

 made : — 



B. 

 35-72 

 35-71 



35-82 

 35-78 



T. 

 34-56 

 34-50 



34-48 

 34-5 



■} 



in one position; 21°*7 C. 

 in another position; 22 o, C. 



Hence in the mean, 



B = 35*76, T = 34-51. 



The units which form the basis of these statements are, however, 

 not the same, since, as mentioned above, the divisions of the j 

 axis and of the rj axis in the scale used were distinctly different 

 from one another. Taking the mean values of the divisions of 

 the scale as given above, we get 



B = 64-34 milhms., 

 But from equation (13) we get 



1 + 



T = 62-41 millims. 



e 



1+2(9 



21' 



(14) 



