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

William Benjamin Carpenter

Date:: 1862

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 which these applications were to be effected, that it was brought into pftblic notice, and made one of the most popular and interesting instruments which science has presented to the arts.” Now, so far was the original reflecting stereoscope of Mr. Wheatstone from being “ a rude and imperfect apparatus,” that, for the purposes of scientific investigation, as well as for the pro- duction of the finest stereoscopic effects, it remains uurivalled by the lenticular; and nothing but its want of portability and the comparative costliness of the large photographic pictures it is fitted to exhibit, prevent its superiority from being generally recognised. So far, again, was Mr. Wheatstone’s invention from being “soon forgotten,” that it has been specially noticed, and its importance fully appreciated, in every standard treatise on phy- siology I am acquainted with—English, French, or German,—and in nearly every work of authority upon physical optics, from 1840 to the present time, besides being exhibited and commented on to their classes by the best-informed teachers both of physiology and of physical science in every country. Further, Mr. Wheatstone himself was continuing his researches in the same direction ; and in 1852 he communicated to the Royal Society a second series of researches on binocular vision, which, for their scientific merit, and for their important bearing on the most interesting questions of the psychology as well as the physiology of the visual sense (questions too recondite to be generally intelligible), leave Sir D. Brewster and his purely optical investigations far behind.* And 1 can assert, from my own knowledge, that the production of those stereoscopic photographs which have given quite a new value to the instrument had been accomplished, not only privately by Mr. Fox Talbot, on Mr. Wheatstone’s suggestion, but by those who practised photography as a matter of business, some time before there is any evidence that Sir D, Brewster turned his attention to the matter. So much, then, for the extraordinary assertion that but for Sir D. Brewster the stereoscope would have been “soon forgotten.” I shall not detain you with examining at any length the assertions of Sir D. Brewster in regard to the approximations to the essential principle of the stereoscope which he affirms to be discernible in the works of previous writers. You may judge of the honesty of his representations by these two facts:—that he makes out from the words of Harris (which 1 just now read to you) that he had come to perceive as a general fact that “the relievo is produced by the combination of the two dissimilar pictures given * Sir D. Brevrster speaks of the Pseudoscope ef Mr. Wheatstone as “ a most capricious ami unsatisfactory instrument, which often fails to show what it ought to show. So far is it from deserving this contemptuous description, that, as I have shown in the Edinburgh Jieview for October, 185S, it is an instrument of the most sineulnr value, as furnishing the means of testing the degree of tenacity with which our minds held to their habitual appreciation of the forms of the several objects around us, notwithstanding the reversal of their retinal images, which, on the purely optical doctrines of Sir D. Brewster, ought in every instance to produce a “ conversion of relief.”

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

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