Page:On the Magnet - Gilbert (1900 translation of 1600 work).djvu/164

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142
WILLIAM GILBERT

from our city of London, changes the verticity at a distance of so many miles; but because the whole magnetick earth, that which projects to a considerable height, and to which the iron is near, and that which is situated between us and the pole, and the vigour existing within the orbe of its magnetick virtue (the nature of the whole conspiring thereto), produces the verticity. For the magnetick effluence of the earth rules everywhere within the orbe of its virtue, and transforms bodies; but those things which are more similar to it, and specially connected with it by nature, it rules and controls; as loadstone and iron. Wherefore in very many matters of business and actions it is clearly not superstitious and idle to observe the positions and conditions of lands, the points of the horizon and the places of the stars. For as when a babe is brought forth into the light from its mother's womb, and acquires respiration and certain animal activities, then the planets and celestial bodies, according to their position in the universe, and according to that configuration which they have with regard to the horizon and the earth, instil peculiar and individual qualities into the newly born; so that piece of iron, whilst it is being formed and lengthened out, is affected by the common cause (to wit, the earth); whilst it is returning also from its heated condition to its former temperature, it is imbued with a special verticity in accord with its position. Rather long pieces of iron sometimes have the same verticity * at each end; wherefore they have motions which are less certain and well ordered on account of their length and of the aforesaid processes, exactly as when an iron wire four feet long is rubbed at each end upon the same pole of a loadstone.

CHAP. XIII.

Why no other Body, excepting a magnetick, is imbued
with verticity by being rubbed on a loadstone; and why no
body is able to instil and excite that virtue,
unless it be a magnetick.

Ligneous substances floating on water never by their own strength turn round toward the poles of the earth, save by chance. So wires of gold, silver, brass, tin, lead, or glass, pushed through corks and floating, have no sure direction; and for this reason they do not show poles or points of variation when rubbed with a loadstone. For those things which do not of themselves incline toward the poles and obey the earth are also not ruled by the