Page:On the Magnet - Gilbert (1900 translation of 1600 work).djvu/123

 magnetical; but in proximity they raise enmities. But if one part of the stone is turned round, so that C faces D and F faces E, then A pursues B within its orbe until they are united.

The Southern parts of the stone avoid the Southern parts, and the Northern parts the Northern. Nevertheless, if by force you move up the Southern cusp of a piece of iron too near the Southern part of the stone, the cusp is seized and both are linked together in friendly embraces: because it immediately reverses the implanted verticity of the iron, and it is changed by the presence of the more powerful stone, which is more constant in its forces than the iron. For they come together according to their nature, if by reversal and mutation true conformity is produced, and just coition, as also regular direction. Loadstones of the same shape, size, and vigour, attract one another mutually with like efficacy, and in the opposite position repel one another mutually with a like vigour.

Iron rods not touched, though alike and equal, do yet often act upon one another with different forces; because as the reasons of their acquired verticity, also of their stability and vigour, are different, so the more strongly they are excited, the more vigorously do they incite.

Pieces of iron excited by one and the same pole mutually repel one another by those ends at which they were excited; then also the opposite ends to those in these iron pieces raise enmities one to another.

In versoria whose cusps have been rubbed, but not their cross-ends, the crosses mutually repel one another, but weakly and in proportion to their length.

In like versoria the cusps, having been touched by the same pole of the loadstone, attract the cross-ends with equal strength.

In a somewhat long versorium the cross-end is attracted rather weakly by the cusp of a shorter iron versorium; the cross of the shorter more strongly by the cusp of the longer, because the cross of the longer versorium has a weak verticity, but the cusp has a stronger.

The cusp of a longer versorium drives away the cusp of a shorter one more vehemently than the cusp of the shorter the cusp of the longer, if the one is free upon a pin, and the other is held in the hand; for though both were equally excited by the same loadstone, yet the longer one is stronger at its cusp on account of its greater mass.

The Southern end of an iron rod which is not excited attracts the Northern, and the Northern the Southern; moreover, also the Southern parts repel the Southern, and the Northern the Northern.

If magnetick substances are divided or in any way broken in pieces, each part has a Northern and a Southern end.