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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    trait photographers of this metropolis that they are quite satisfied that these pictures were not drawn with any idea of giving stereo- scopic relief. That these gentlemen do not wish their names to he drawn into the discussion, you will readily understand from a sample I shall presently give you of Sir D. Brewster’s mode of dealing with antagonists who venture to dispute his dicta * But even if it were true, as Sir D. Brewster and the Photo- graphic Society of Scotland assert, that these pictures when com- bined in the stereoscope give a true effect of relief, the assumption that they were drawn to he so combined, and that Chimenti was the “inventor of the ocular stereoscope,” is altogether gratuitous. It seems to be altogether forgotten that, when the pupils of an Academy are set to draw from the living model or from a statue, any two of their drawings, done to the same scale, and from points of view ten or twelve degrees distant, will necessarily pair in the stereoscope, and will produce the effect of relief; and that multi- tudes of such drawings have been executed from the earliest period of art-study to the present time, without the smallest con- ception that such a use could be made of them. If a master and a pupil were making two such drawings from the same model, it would not be at all out of accordance with the practice of artists for the master to put his name to the drawing of the pupil, touched up (if necessary) by himself. Having thus disposed of these asserted anticipators of Mr. Wheatstone from among the dead, I now turn to the claimants set up by Sir D. Brewster from among the living. Mr. Wheatstone having found, on the publication of his second memoir in 1852, that his first (of 1838) was far from being generally known, caused it to be republished in the Philosophical Magazine; and it then, for the first time fell under the notice of Mr. Elliot, a teacher of mathematics in Edinburgh, who forthwith announced his own claim to priority in the idea that the union of the two dissimilar retinal pictures is the source of our appreciation of the relative distances of different objects. This idea, and the means of putting it to an experimental test, occurred to him, he states, in 1834; but he did not carry it out till 1839, and he then constructed, not a stereoscope, but merely a pair of pictures which he superposed by the convergence of the optic axes; and these pictures consisted, not of perspective projections of solid objects, but of landscape sketches with three distances, which distances, by this super- position, were rendered distinguishable. * As Sir D. Brewster lias assumed that Mr. Wheatstone and his friends (among whom lie includes every person who coincides with him in this opinion) cannot see the stereo- scopie effect « f these pictures because they require transposition, I have separated and transposed them without in the least improving the effect; and the fact that the pic- tures are seen nearly as well in one way as in the other—some parts being seen in relief when they are placed L and R, and others when they are placed K aud L—shows tlint tiie pictures are not truly stereoscopic. (See Appendix].