On the Magnetic Susceptibility of Liquid Oxygen. 313 



double cotton-covered copper wire on the bobbin is 71 Ibs., and the 

 total length of wire is roughly about 3300 feet. The total number of 

 turns of wire on the bobbin is 2478. The wire is capable of carry- 

 ing 12 or 14 amperes for considerable periods of time without 

 dangerous heating. The total resistance of the wire is very nearly 

 5-5 ohms at 20 C. 



This bobbin of wire is enclosed in a cylinder of mild steel 

 of the same height as the bobbin, the walls of which are 

 2 '5 cm. thick. This cylinder has movable circular end plates of 

 steel 2 '5 cm. in thickness fitting it, and in these plates are circular 

 holes 9 cm. in diameter. A sofb steel core was also provided, 



V, vacuum vessel ; B, ball weighed ; W, wire windings of magnet ; S, C, steel 

 shell and magnet core. 



37 cm. in length and 9 cm. in diameter, and having steel studs 

 screwed into *j it so that the core could be held in he position 

 shown in the diagram. The end surface of the inner core was 

 7'5 cm. below the upper surface of the wire coil. The steel used 

 is high permeability magnet steel. 



2 A 2 



