400 Lord Blythswood and Dr. Marchant on 



the line we have condition (1). In the photograph, however, 

 two equal orders were showing when there was no magnetism; 

 and there is therefore only one group of lines in the centre of 

 the field, instead of the two groups shown in the diagram. ^ 



Below are given the results of the measurements made with 

 this line. 



X = 5460 tenth-metres. 



H. 



12,900 

 17,800 

 20,000 

 23,000 

 23,400 



8,700 

 13,000 



The mean values obtained from these measurements give : — 

 §= 6-5x10-6, ^= 2-3x10-^ 



^ = 32-4 x 10- 6 , J^| = 10-9 x 10- l3 , 



^ 3 = 6-6 xlO" 6 , ^= 2-22 XIO" 13 , 



X being expressed in 10~ 10 metres. 



Measurements were also made on the yellow (5768) line. 



This line splits into a pure triplet viewed across the lines of 

 force, and into a corresponding doublet when viewed along 

 the lines of force. Under the strongest field there appeared 

 to be no tendency for these lines to split further. The dif- 

 ference in wave-length between the outer components was 

 measured with a micrometer-eyepiece. 



The results of the measurements are given below; for the 



8\ v 

 •981 



dAJHxlO 6 . 

 6-3 



dX 2 . ^X 2 /HxlO G . 

 •416 323 



S\ 5 . 

 6-082 



5X 3 /HX1 

 6-4 







•588 32-9 



•124 



69 



•133 



6-6 













•74 32-3 



•156 



6-8 



•156 



6-7 











Along the lines of force. 











•282 32-5 











•415 32-0 



•085 



6-5 



