ACTION OF MAGNETS ON HEAVY GLASS. 
25 
2261. If the bar be equidistant from the two poles, and in the axial line, then no 
repulsive effect is or can be observed. 
2262. But preserving the point of suspension in the equatorial line, i. e. equidistant 
from the two poles, and removing it a little on one side or the other of the axial line 
(2252.), then another effect is brought forth. The bar points as before across the 
magnetic line of force, but at the same time it recedes from the axial line, increasing 
its distance from it, and this new position is retained as long as the magnetism con- 
tinues, and is quitted with its cessation. 
2263. Instead of two magnetic poles, a single pole may be used, and that either in 
a vertical or a horizontal position. The effects are in perfect accordance with those 
described above; for the bar, when near the pole, is repelled from it in the direction 
of the line of magnetic force, and at the same time it moves into a position perpen- 
dicular to the direction of the magnetic lines passing through it. When the magnet 
is vertical (2246.) and the bar by its side, this action makes the bar a tangent to the 
curve of its surface. 
2264. To produce these effects, of pointing across the magnetic curves, the form of 
the heavy glass must be long ; a cube, or a fragment approaching roundness in form, 
will not point, but a long piece will. Two or three rounded pieces or cubes, placed 
side by side in a paper tray, so as to form an oblong accumulation, will also point. 
2265. Portions, however, of any form, are repelled : so if two pieces be hung up at 
once in the axial line, one near each pole, they are repelled by their respective poles, 
and approach, seeming to attract each other. Or if two pieces be hung up in the 
equatorial line, one on each side of the axis, then they both recede from the axis, 
seeming to repel each other. 
2266. From the little that has been said, it is evident that the bar presents in its 
motion a complicated result of the force exerted by the magnetic power over the 
heavy glass, and that, when cubes or spheres are employed, a much simpler indica 
tion of the effect may be obtained. Accordingly, when a cube was thus used with 
the two poles, the effect was repulsion or recession from either pole, and also reces- 
sion from the magnetic axis on either side. 
2267- So, the indicating particle would move, either along the magnetic curves, or 
across them ; and it would do this either in one direction or the other ; the only con- 
stant point being, that its tendency was to move from stronger to weaker places of 
magnetic force. 
2268. This appeared much more simply in the case of a single magnetic pole, for 
then the tendency of the indicating cube or sphere was to move outwards, in the di- 
rection of the magnetic lines of force. The appearance was remarkably like a case 
of weak electric repulsion. 
2269. The cause of the pointing of the bar, or any oblong arrangement of the 
heavy glass, is now evident. It is merely a result of the tendency of the particles to 
move outwards, or into the positions of weakest magnetic action. The joint ex- 
mdcccxlvi. e 
