100 J. Nicklés on Magnetisation. 
horse-shoe magnet (fig. 1), one leg of which is moveable and 
may be removed at pleasure. The joining piece, by which these 7 
two bars are made a horse-shoe magnet, is a rectangular iron bar, — 
of convenient length, having a groove in the direction of the — 
. j 
, So that the two poles — 
rone of their sidesif — 
r one another. 
would give ; besides, as the legs may be indefinitel y separated, tt 18) 
easy to place them in extreme conditions, and so decide the que> — 
tion at a single trial. Ihave used a constant current, a needle 
being employed to test it. 
Distance between the poles, Current a. Current 6. 
8 leaves of paper (3 mm.) 14-15 kil. 52 kil. 
120 mm. 18 is 65 “ 
each 47 meters of wire 1mm. in diameter, and finally that the 
armature z, was a cylinder of iron 15 mm. thick and 30 cel- 
timeters long. 
