INTENSITY OF THE EARTH'S MAGNETIC FORCE. 



257 



feet ; the second, the values of | (n e - w ), these values being the 

 means of those obtained with the deflecting magnet on the east and 

 on the west side of the suspended magnet ; the third column con- 

 tains the calculated values of u ; and the fourth those of D 3 tan u. 

 In the observations of I., II., and III., the lengths of the deflect- 

 ing and suspended magnets were in the ratio of the numbers 1'224 

 to 1 ; in those of IV. and V., the lengths of the two magnets were 

 equal. 



I. Magnet away, Scale reading = 496-5 . . . 494-5. 



III. Magnet away, Scale reading = 496-4 . . . 494-3. 



IV. Magnet away, Scale reading - 494-4 . . . 494-6. 



