Licence: Public Domain Mark
Credit: Inquiries into human faculty and its development / by Francis Galton. Source: Wellcome Collection.
Provider: This material has been provided by the Royal College of Physicians of Edinburgh. The original may be consulted at the Royal College of Physicians of Edinburgh.
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![editions of them, are the analogues of these composite pictures which we have the advantage of examining at leisure, and whose peculiarities and character we can investigate, and from which we may draw conclusions that shall throw much light on the nature of certain mental processes which are too mobile and evanescent to be directly dealt with. III. Composite Portraiture. [Bead before the Photographic Society, 2ith June 1881.] I propose to draw attention to-night to the results of recent experiments and considerable improvements in a process of which I published the principles three years ago, and which I have sub- sequently exhibited more than once. I have shown that, if we have the portraits of two or more different persons, taken in the same aspect and under the same conditions of light and shade, and that if we put them into different optical lanterns converging on the same screen and carefully adjust them—first, so as to bring them to the same scale, and, secondly, so as to superpose them as accurately as the conditions admit—then the different 'faces will blend sur- prisingly well into a single countenance. If they are not very dissimilar, the blended result will always have a curious air of individuality, and will be unexpectedly well defined; it will exactly resemble none of its components, but it will have,a sort of family likeness to all of them, and it will be an ideal and an averaged portrait. I have also shown that the image on the screen might be photographed then and there, or that the same result may be much more easily obtained by a method of suc- cessive photography, and I have exhibited many specimens made on this principle. Photo-lithographs of some of these will be found in the Proceedings of the Royal InstiMion, as illustrations of a lecture I gave there On Generic Images in 1879. The method I now use is much better than those previously described; it leads to more accurate results, and is easier to manage. 'l will exhibit and explain the apparatus as it stands, and will indicate some improvements as I go on. The apparatus is here I use it by gaslight, and employ rapid dry plates, which, however, under the conditions of a particularly small aperture](https://iiif.wellcomecollection.org/image/b21914631_0376.jp2/full/800%2C/0/default.jpg)
