HOOVER'S COMBINED SHUTTER AND DIAPHRAGM
De Witt C. Hoover, Buffalo, New York 1885-1891
Hoover's Combined Shutter and Diaphragm, as it's referred to in the patent title and in The Scientific American 1885, or just "The Hoover Shutter" as seen in some advertisements, was designed by De Witt C. Hoover of Buffalo, New York, with Patent No. 317,788 granted to him on May 12, 1885. Like Benster's Patent Diaphragm Shutter of the same era, Hoover's shutter was fitted to a lens of the photographer's choice:
Source: U.S. Patent and Trademark Office
As reported in The Scientific American Supplement, Volume XX, No. 500, August 1, 1885, Hoover's shutter was exhibited at a recent convention of photographers in Buffalo, New York. The magazine went on to describe its construction and operation: "It consisted of having two light thin strips of gutta-percha pass in slits through the lens tube in the place usually occupied by the diaphragm. The principle of the movement was "go and return," and the strips were operated by a toggle joint and a coiled watchspring. Diamond shaped openings were made in the strips, and the size of the diaphragm was regulated according(ly) as the strips were drawn apart or closed together. The whole was neatly encased in a gutta-percha box. It possessed the advantage of allowing the operator to make a time or an instantaneous exposure at will with any size diaphragm he might desire to use. It also tended to make pictures taken instantaneously, much sharper and more distinct than is usually the case. When the spring was placed at its highest tension it was estimated an exposure of the mere fraction of a second could be made. Another feature of the invention was the absence of any jar."
Hoover's Combined Shutter and Diaphragm stands out among other shutters of the period, having been constructed largely of a thermoplastic material. Although gutta-percha was used, most of us would probably describe it as being Bakelite, which wasn't actually developed until 1907. Hoover's shutter was also available in a stereoscopic version.
Little is known of De Witt C. Hoover, and it is assumed that he was the manufacturer. W.H. Walmsley & Company of Philadelphia marketed the Hoover, but it is not known whether they were involved in its manufacture. Hoover died in September, 1897 and his passing was noted in the American Amateur Photographer, Volume IX, No. 12, December, 1897, with an obituary by his nephew, C. Elmer E. Hoover of Buffalo, New York, stating that Hoover died suddenly after being stricken with Apoplexy while on his private yacht, Vixen, during a pleasure trip to Cayuga Island in the Niagara River. At the time, he was about to complete a new film for the Kinetoscope, and to make public his discoveries in porcelain. Per his nephew, Hoover invented all the machinery used in his photographic paper factory. This is evidenced by patents held by Hoover for a photographic printing machine (Patent No. 462,382) and an improved package for photographic plates (Patent No. 402,827).
This example has casing measurements of 3-1/16" x 6" x 13/16" thick. The lens with a 2-1/2" barrel diameter is unmarked as to maker. "D.W.C. Hoover's Patent May 12th 1885" is found molded into the casing:
Hoover's Combined Shutter and Diaphragm was still being advertised by the photographic supply firm of Tucker & Butts as late as 1891, as seen in The International Annual of Anthony's Photographic Bulletin for that year.
Very few examples exist today, and the shutter can be considered rare.
From W.H. Walmsley & Co.'s Illustrated Catalogue of Photographic Cameras, Lenses, September 1, 1886
Front cover of W.H. Walmsley & Co.'s Illustrated Catalogue of Photographic Cameras, Lenses, September 1, 1886
Back cover of W.H. Walmsley & Co.'s Illustrated Catalogue of Photographic Cameras, Lenses, September 1, 1886
From The International Annual of Anthony's Photographic Bulletin for 1891
Front cover of The International Annual of Anthony's Photographic Bulletin for 1891