Coleman Sellers Biography 1827–1907 Page 4

INVENTIONS AND INTEREST IN PHOTOGRAPHY

A photographic dark room was established as a regular adjunct of the draughting office of William Sellers & Co. , and special cameras and apparatus were devised, the apprentices taking turns in printing, developing, and mounting the photographs. His success in this special application of photography to his business led him to try portrait and landscape work in his hours of relaxation, and for years this proved his most absorbing hobby. In its pursuit he invented several useful aids for the photographer, patented a cheap and effective rolling press for mounting prints, and made various ingenious portable dark chambers or “tents” for field work with the “wet” process.

Washing negatives after development and before “fixing” was one of the difficulties of field work at that time, as it was not always easy to procure the necessary supply of water, and to carry it about added a considerable weight to the apparatus; but Dr. Sellers discovered that washing might be deferred to a more convenient season if the plate be coated with a mixture of glycerine and water and then shut up in a tight box. This enabled him to preserve “unfixed” plates for months, and greatly simplified the practice of field photography by the wet process, which has long since, however, given way to the “dry” plate.

During 1861 and 1862 he acted as American correspondent for the British Journal of Photography, and was for many years a frequent contributor to American photographic publications. He was one of the founders of the Philadelphia Photographic Society, as well as a prominent member of the Amateur Exchange Club, an active organisation founded in 1861 by Mr. H. T. Anthony, of New York, which included in its membership a number of bright men in various walks of life.

In 1861, Dr. Sellers made and patented a device which he called the kinematoscope for the exhibition of stereoscopic pictures of objects in motion, which, in point of fact, was the crude prototype of the modern machines for displaying moving objects, such as the biograph, kinetoscope, and others. The machine accomplished the object intended in a practical manner, but required for its full development instantaneous photography, which had not at that time been invented. As will be seen by reference to the illustration, the stereoscopic prints were mounted radially around a horizontal axis, so that rotation brought them successively before the lenses. The operation to be reproduced was divided into a suitable number of parts, the subject being posed for each part of the movement. As many seconds were required for each pose with the slow plates then used, great care was necessary on the part of the operator and model to get perfect registration of the successive views. [continue]