1890.] On a neio Magnetometer. 2<>7 



cm. 

 Beading for needle before reversal. . . . 6*21 



after 88*69 



Difference 82*48 



Weight suspended from bifilars = 11 '3 7 grams. 

 Length of bifilars measured by cathetometer = 30*07. 

 Distance apart of bifilars at top = 0*5092 inch = 1'293 cm. 



below = 0-5173 = 1-314 

 Diameter of circular magnet = 27*50 cm. 



From which data H = 0*1803. 



II. May 20, 1890. 4 P.M. Scale 2 metres long, placed 2 metres 

 from instrument. Distance between bifilars below altered and weight 

 changed in consequence. 



cm. 



Reading for magnet before reversal . . 153'66 

 after 77*34 



Difference .. 76*32 



cm. 



Reading for needle before reversal. . . . 191*76 

 after 25*40 



Difference. . . . 166*36 



Weight = 11 89 grams. 



Distance between bifilars below = 5126 inch = 1*302 cm. 



Length of bifilars = 27*81 cm. Other constants as before. 



H = 0*1805. 



III. May 20. 5 P.M. Constants same as in II. 



cm. 



Reading for magnet before reversal . . 153*69 

 after 77*72 



Difference. . 75*97 



cm. 



Reading for needle before reversal. . . . 192*51 

 after .... 26*67 



Difference 165'84 



H = 0*1803. 



u 2 



