CHAP. XXVIII.

A Loadstone attracts magneticks not only to a

fixed point or pole, but to every part of a

_terrella save the æquinoctial zone_.

Coitions are always more powerful when poles are near poles, since in them

by the concordancy of the whole there exists a stronger force; wherefore

the one embraces the other more strongly. Places declining from the poles

have attractive forces, but a little weaker and languid in the ratio of

their distance; so that at length on the æquinoctial circle they are

utterly enervated and evanescent. Neither do even the poles attract as

mathematical points; nor do magneticks come into conjunction by their own

poles, only on the poles of a loadstone. But coition {97} is made on every

part of the periphery, both Northern and Southern, by virtue emanating from

the whole body; magneticks nevertheless incline languidly towards

magneticks in the parts bordering on the æquator, but quickly in places

nearer the pole. Wherefore not the poles, not the parts alone nearest to

the pole allure and invite magneticks, but magneticks are disposed and

turned round and combine with magneticks in proportion as the parts facing

and adjoined unite their forces together, which are always of the same

potency in the same parallel, unless they are distributed otherwise from

causes of variation.

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On the magnet, magnetick bodies also, and on the great magnet the earth a new physiology, demonstrated by many arguments & experiments · 第 47 / 110 题