On binocular vision and the stereoscope : a lecture delivered at the London Institution, March 19, 1862 / by William B. Carpenter.

  • Carpenter, William Benjamin, 1813-1885.
Date:
1862
Catalogue details

Licence: Public Domain Mark

Credit: On binocular vision and the stereoscope : a lecture delivered at the London Institution, March 19, 1862 / by William B. Carpenter. 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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    by each [either] eye,” whereas Harris says no such thing, but something essentially different; and that he asserts that Agudo- nius was acquainted with the dependence of the appearance ot solidity upon the dissimilarity of the pictures of the objects, when the fact is that the solids (t» artpea) of which Aguilonius speaUS are not actual solid objects, but the imaginary solids formed by lines drawn between the angles of the objects (which may be plane surfaces) and the eye. Aguilonius was puzzled by the dis- similarity of these errepea when the object is placed nearer to one eye than to the other; and attributes the union of the two dis- similar pictures to a “common sense,” without the slightest hint of the notion that in this union lies the essential cause of our perception of solidity.* It is not a little singular, moreover, that Aguilonius, like Euclid, Galen, Baptista Porta, Leonardi da Vinci, and other writers who discussed the subject of binocular vision, drew their illustrations from objects with rounded surfaces, such as spheres or cylindrical columns. These, it is obvious, are the very last objects they would have chosen if they had wished to draw attention to the dissimilarity of the perspective projections; since the retinal picture of any such object placed equally in front of both eyes will be identical, except as regards any shadows its surface may present. Let me cite, with reference to these and other asserted anticipa- tions of Mr. Wheatstone’s discovery of the essential principle of stereoscopic vision, the following very true remark, long since made by a distinguished scientific man with regard to a beautiful invention of his own, of the merit of which he complained that others were attempting to deprive him :—“ It has always been the fate of new inventions to have their origin referred to some remote period ; and those who labour to enlarge the boundaries of science, or to multiply the means of improvement, are destined to learn, at a very early period of their career, that the desire of doing justice to the living is a much less powerful principle than that of being generous to the dead.” You would scarcely anticipate from what has-gone before that the invention to which these remarks apply was the Kaleidoscope, and that the inventor was Sir D. Brewster ! Surely a scientific man who had himself suffered from the depre- ciation of which he thus complains, should be the last to practise it towards a brother philosopher whose discoveries he had at first so warmly appreciated. Before quitting the subject of these asserted anticipations, I must draw your attention to certain statements recently put forth by Sir D. Brewster in regard to two drawings by an Italian artist of the sixteenth century named Chimenti, which are pre- served in the Museum at Lille, and which were reported to Sir D. * In fact, he expressly states that when the object is placed directly in trout of the eyes, the OTtpea or optical pyramids are similar.