Unity of Purpose, or Rational Analysis; Being a Treatise Designed to Disclose Physical Truths, and to Detect and Expose Popular Errors (Paperback)

This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated.1846 Excerpt: ... CHAPTER II. On the Law of Gravity, and the Popular Deduction and Promulgation of the Supposed Law. SECTION FIRST. Gravity may properly be defined to be (at least for the purposes of this article) that physical power which pervades the solar system, (and perhaps, judging by analogy, the universe, ) displayed or manifested to our senses in and through the medium of tangible matter, by which the phenomenon is constantly presented to our perception, of aggregate bodies of matter attracting each other, at least under certain circumstances; and hence we observe bodies falling from a state of rest towards the centre of the earth; and hence the centripetal force which retains the planets in their orbits around the sun, and the satellites in their orbits around their primaries. To present and more readily compare the popular notions of gravity with suggestions or hypotheses which I may attempt to intrude in place of them, I will suggest the consideration of the subject under two heads, namely: the theory of gravity, and the law of gravity. The theory of gravity will mainly be referred to the momentous question, --whether tangible or aggregate matter, of itself, is endued with or possessed of innate or inherent gravity, or an inherent power to attract and be attracted, just in proportion to the quantity of aggregate matter, wherever situated, in the solar system, (for I will not attempt to investigate beyond that, ) which theory may be termed the theory of inherent gravity;--or, whether the power incident to a given quantity of matter to attract, or the susceptibility to be attracted, must depend upon some numerical law in respect to its distance from the sun, or great centre of gravity of the solar system, --which may be termed incidental or incited gravity. The law of