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. 1851 Excerpt: ...uprightly or obliquely), --that paper will hide part of the wall from my eye. Now, the part of the wall thus hidden, is the projection of the paper on tliat wall. In the same manner, if, standing up, I placed the paper hetween my eye and the surface of the table, the part of the table hidden by the paper would be the ...
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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. 1851 Excerpt: ...uprightly or obliquely), --that paper will hide part of the wall from my eye. Now, the part of the wall thus hidden, is the projection of the paper on tliat wall. In the same manner, if, standing up, I placed the paper hetween my eye and the surface of the table, the part of the table hidden by the paper would be the projection of the paper on the surface or plane of the table. If in this latter case the paper were held horizontally or as if along the table, the projection would evidently be of the same size as the paper itself, or nearly so; but if the paper were held obliquely, or slanting, its projection would be less than itself in exact proportion to the degree in which it slanted; nay, if one held it edgewise, the projection would be reduced to the mere thickness of the paper. This understood then, let us recur to our old illustration (page 69) of a solar system represented in relation to the surface of the table--the sun being placed at its centre. Reflect first on the case of one planet, whose orbit is not on the plane of the table, but inclined to it, one half above and the other half below. The radius vector (page 89) of that planet must evidently be inclined to the table, it being necessarily in the plane of the planet's orbit; which radius would therefore describe, in the course say of a month, a triangular space represented by a triangular piece of paper lying obliquely towards the table, and with its apex at the sun. Once more, --let the mind be fixed on the projection of this triangle on the surface of the table, and call that projection the area described in a certain time by the radius vector of the planet in question, measured on the plane of the table. Now, the process thus gone through with regard to one planet, may be easily supposed to t.
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Add this copy of The Planetary System Its Order, and Physical Structure to cart. $28.63, new condition, Sold by Paperbackshop rated 4.0 out of 5 stars, ships from Bensenville, IL, UNITED STATES, published 2019 by Hardpress Publishing.
Add this copy of The Planetary System: Its Order, and Physical Structure to cart. $38.49, new condition, Sold by Booksplease rated 4.0 out of 5 stars, ships from Southport, MERSEYSIDE, UNITED KINGDOM, published 2019 by Hardpress Publishing.
