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. 1872 Excerpt: ...of their intersection, as shown by the objects 1, 2, and 3. As the superficial magnitude of an object is as the square of the lineal magnitude, the apparent superficial magnitude of an object will be inversely as the square of the distance. Tlie smallest visual angle under which an object can be seen, with the naked ...
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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. 1872 Excerpt: ...of their intersection, as shown by the objects 1, 2, and 3. As the superficial magnitude of an object is as the square of the lineal magnitude, the apparent superficial magnitude of an object will be inversely as the square of the distance. Tlie smallest visual angle under which an object can be seen, with the naked eye, is about twelve seconds. 449. Inversion of images formed in the eye.--The camera obscura (439) and the structure of the eye are sufficient proof of the inversion of images on the retina; but, for ocular proof, take the eye of an ox, cut away the posterior part of the sclerotic and choroid coats; fix the eye in an opening in the shutter of a dark room, look at it with a magnifying glass, and external objects will be seen beautifully delineated in an inverted position on the retina. Jf50.--Why we see objects erect, their images being: inverted, is explained in different ways by different philosophers; but probably it is because, the image always being inverted, the mind, by unconscious training, is habituated to it; learning from the beginning to refer the impression it receives to the upright position of the object. J/.51--The brightness of the ocular image.--The intensity of light diminishes as the square of the distance it travels increases; see Fig. 50 (529). Hence, the brightness of an object, by this law, would be inversely as the square of the distance. The apparent superficial magnitude of an object also diminishes as the square of the distance increases (447). Hence, as the intensity of the light (or brightness of the object) will be increased by the apparent diminution of surface over which it is spread, in the same ratio that its intensity will diminish by the increase of distance, it follows that The apparent brightness of an obje...
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Add this copy of Natural Philosophy, and Key to Philosophical Charts to cart. $50.41, good condition, Sold by Bonita rated 4.0 out of 5 stars, ships from Newport Coast, CA, UNITED STATES, published 2011 by Nabu Press.