Among the many other ingenious and useful hand cameras may be mentioned the “Premo,” made by the Rochester Optical Company, and shown in Fig. 205. The “Premo” is arranged for either snap-shot or time exposure, is adapted to be either held in the hand or mounted upon a tripod, and is furnished for use either with glass plates or roll films. In Fig. 206 is shown the “Premo” for stereoscopic work, in which two pictures are taken at once, a sufficient distance from each other to produce the effect of binocular vision and give the appearance of relief when viewed through the stereoscope. Brett’s British patent No. 1,629, of 1853, appears to be the earliest description of a stereoscopic camera. [Illustration: FIG. 206.--STEREOSCOPIC CAMERA.] There have been 2,000 United States patents granted in photography, most of which have been taken in the past thirty years, and great efficiency and detail in both the chemical and mechanical branches of the art have been obtained. The useful applications of the art have been numerous and varied. _Portrait making_ is probably the largest field. This was first successfully accomplished in 1839 by Professor Morse, of telegraph fame, working with Prof. John W. Draper, of the University of New York. _Celestial Photography_ began with Prof. Draper’s photograph of the moon in March, 1840, and Prof. Bond, of Cambridge, Mass., in 1851. In 1872 Prof. Draper photographed the spectra of the stars, and in 1880-81 the nebulæ of Orion, and in 1887 the Photographic Congress of Astronomers of the World, organized in Paris, began the work of photographing the entire heavens. In late years notable work has been done at the Lick Observatory by Prof. Holden. In 1861 Mr. Thompson, of Weymouth, photographed the bottom of the sea, and Prof. O. N. Rood, of Troy, N. Y., the same year described his application of it to the microscope. In 1871 criminals were ordered to be photographed in England, and in America the Rogues’ Gallery became an institution in New York as early as 1857, ambrotypes being first used. In 1876 the Adams Cabinet for holding and displaying the photos was invented. To-day the New York collection amounts to nearly 30,000, while that of the National Bureau of Identification at Chicago approximates 100,000. It is a striking illustration of the law of compensation that the counterfeiter who invokes the aid of photography to copy a bank note is, by the same agency of his photo in the Rogues’ Gallery, identified and convicted.