MAGNETIC OBSERVATIONS. 



Magnet C. 32. 



51 



Hence for the magnet C 32, we have 

 i scale division = 2'. 349 o'.oo2o. 



MagnetS. 8. 



Hence, for the magnet S 8, we have 

 i scale division = 2'.835 o'.ooi3. 



TJie Moment of Inertia, and its Temperature Coefficient, of the Magnet C 32, was 

 determined as follows : Let, 

 JT T = moment of inertia of the magnet, including its suspending stirrup and other 



appendages, at the temperature r. 

 AK= change in the value of K corresponding to a change of temperature of 1 



Fah. in the magnet. 



K'^ = moment of inertia of the inertia ring, at the temperature r. 

 d t = internal diameter of the inertia ring, expressed in feet, at the temperature <r . 

 d e = external diameter of the inertia ring, expressed in feet, at the temperature T O . 

 f = coefficient of expansion for a change of temperature of 1 Fah. in the metal 



composing the inertia ring. 

 W = weight of the inertia ring expressed in grains. 



