414 Prof. Wood on the Magneto- Optics of Sodium Vapour 



Centre 30°. j Centre 90° con, 



58971 

 58968 

 589(V5 

 5895-4 

 5895-3 

 5894-9 

 5893-2 

 5891-4 

 5890-9 

 5890 6 

 5889-3 

 5889-0 

 5888-7 



90 



180 



270 



270 



180 



90 



30 



90 



ISO 



270 



270 



180 



90 



Centre 50 c 



5898-4 

 5897-8 

 5897-6 

 5897-3 

 58970 

 5896-7 

 5895-3 

 5894 9 

 58946 

 5893-2 

 5891-9 

 5891-4 

 5891-0 

 5889-1 

 5888-7 

 5888-3 

 5887-8 

 5887-6 

 5886-9 



30 

 45 

 60 



90 



180 



270 



270 



180 



90 



50 



90 



180 



270 



270 



ISO 



90 



60 



45 



30 



Centre 90 c 



5899-7 



5899-3 



5898-8 



5898-3 



5897-8 



5897-45 



5897-1 



5896-8 



5895-3 



5895-0 



20 

 30 

 40 

 60 



90 

 180 

 270 

 360 

 451 

 360 



5S94 

 5894 

 5893 

 5891 

 5891 

 5891 

 5891 

 5890 

 5889 

 5888 

 5888 

 5888 

 5887 

 5886 

 5886 

 5S86 

 5884 



270 

 180 

 90 

 180 

 270 

 360 

 450 



5 



4 



•34 



9 



5 



3 



1 



86 640 



450 



8 360 

 270 

 180 

 90 

 60 

 40 

 30 

 20 



•;> 

 "2 

 •5 



•96 



•5 







Ceni're 180 c 



5901-3 



5900-3 

 5S994 

 5899-0 

 5898-2 

 5897-7 

 5897-3 

 5897-1 

 5896-9 

 5894-9 

 5<°94-7 

 5894-5 

 5894-1 

 58932 

 5891-9 

 5891-6 

 5891-3 

 5891-2 

 5888-6 

 5S88-4 

 5888-2 

 5887-9 

 5887-5 

 5886-8 

 5886 2 

 5885-4 

 5884-6 

 5883-2 



20 



30 



40 



60 



90 



180 



270 



360 



450 



540 



450 



360 



270 



180 



270 



360 



450 



540 



540 



450 



360 



270 



186 



90 



60 



40 



30 



20 



Centre 450°. I Centre 540° con. 



5902 1 

 5902-2 

 5900-3 

 5899-4 

 5898-7 

 5898-0 

 5897-7 

 5897-5 

 5897-3 

 5894-8 

 5894-7 

 5894-5 

 5894-2 

 5894-0 

 5893-2 

 5892-3 

 58921 

 5891-8 

 5891-5 

 5888-3 

 5888-1 

 5887-9 

 5887-7 

 5887-4 

 5886-9 

 5886-1 

 5884-7 

 5883-2 

 5881-7 

 5880-3 



30 



40 



60 



90 



180 



270 



360 



450 



540 



900 



810 



720 



030 



540 



450 



540 



630 



720 



810 



720 



630 



540 



450 



360 



270 



180 



90 



60 



40 



30 



Centre 540 c 



5902-8 

 5901-5 

 5900-1 

 5898-8 

 5898-3 

 5898-0 

 5897-7 

 5894-4 

 5893 7 

 5893-5 

 5892-4 

 5892-1 

 5891-8 

 5891-7 



40 

 60 

 90 

 180 

 270 

 360 

 450 

 720 

 630 

 540 

 630 

 720 

 810 

 900 



588S-0 

 5887-8 

 5887-4 

 5887-1 

 5886-7 

 5886-1 

 5884-6 

 5383-2 

 5881-5 



630 

 540 



450 

 360 

 270 

 180 

 90 

 60 



40 



Centre 720°. 



5875-0 



20 



5876-3 



25 



5880-5 



50 



5881-4 



60 



5882 6 



80 



5883-2 



95 



5885-7 



180 



5887-0 



270 



5893-5 



720 



58990 



180 



5900-8 



97 



5901-8 



80 



5902-8 



61 



5903-6 



50 



5908-0 



25 



5909-7 



20 



Centre 960°. 



5903-9 

 5902-0 

 5900-2 

 5899-6 



5899-2 



5898-8 



60 

 90 



180 

 270 

 360 

 450 



5893-4 960 



5886-6 



5886-3 

 5885-9 



5885-1 

 5884-5 

 5881-8 

 5880-0 



540 

 450 

 360 

 270 

 180 

 90 

 60 



A number of photographs of the spectrum with the dark 

 bands in different positions were made with a large three- 

 prism spectrograph, recently constructed for the study of the 

 fluorescence spectrum (PI. V. fig. 2). It was at first thought 

 that by measuring the positions of the bands on the negatives, 

 more accurate results could be obtained than by visual 

 observations ; but the reverse proved to be true, though fairly 

 good curves were obtained. The density of the vapour was 



