Elements of physics, or, Natural philosophy : general and medical, written for universal use, in plain or non-technical language, and containing new disquisitions and practical suggestions / by Neil Arnott.

  • Arnott, Neil, 1788-1874.
Date:
1833
Catalogue details

Licence: Public Domain Mark

Credit: Elements of physics, or, Natural philosophy : general and medical, written for universal use, in plain or non-technical language, and containing new disquisitions and practical suggestions / by Neil Arnott. Source: Wellcome Collection.

Provider: This material has been provided by King’s College London. The original may be consulted at King’s College London.

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    tions or changes which are going on around him, is to man of the greatest importance, as it enables him to adapt his actions to what is coming in futurity, and often to interfere so as to control futurity, for his special purposes. Motion, in any particular case, is described by referring to certain objects to mark place, and to some other motion chosen as a standard of ve- locity.—A man sitting on the deck of a sailing ship, has common motion with the ship: if walking on the deck, he has relative motion to the ship: but if he be walking towards the stern, just as fast as the ship advances, he is at rest relatively to the bottom or shore. A ship sailing against the tide, just as fast as the tide runs, is as much at rest relatively both to the earth and water, as if she were at anchor. Absolute motion is that which is relative to the whole universe, or rather to the space in which the universe exists. We have no means of ascertaining such : for although we know how fast our globe whirls upon its axis and wheels round the sun, we have no measure of the motion of the sun himself—revolving possibly round some more distant centre, but almost certainly having a progress in space, and carrying all the planets along with him. Motion is called rapid, as that of lightning— slow, as that of the sun-dial shadow : both terms having reference to the ordinary intermediate velo- cities observed upon earth. It is called siraight, or reciilineal, in the apparent path of a falling body—bent, or curvilinear, in the track of a body thrown obliquely—accelerated, in a stone falling