CAMERA (Pr., Chambre a ail de Poisson ; Ger., Fischenauge-hamera) J. Alan Stewart, M.A., has published a method of obtaining photographs resembling the views that would be seen by the eye of a fish. Objects against the light of the sky are only perceived by the fish when they fall within the limits of a right-angled cone, whose apex is at the fish's eye, while the base is a circle on the surface of the water, of a little larger radius than the depth of the fish. To produce a photographic imitation of these conditions, a box having a pinhole instead of a lens was employed. Although light-tight except to rays entering by the pin hole, the box was not watertight, but admitted water freely. The sensitive plate was placed 5 in. from the pinhole and the camera was immersed in a larger box filled with water, the exposure being then made on an object—a phantom minnow, for example-3 or 4 in. below the surface of the water in the exterior vessel. An isochromatic plate was used, satisfactory results being obtained with five minutes' expo sure in bright sunlight.
R. W. Wood advises the following procedure : A small pail is taken, and into this, rather over half-way, up, is fitted a metal disc having a perforated pinhole. The photographic plate is laid at the bottom of the pail in the dark-room, and the pail is filled with clean water, both above and below the metal disc. The pail, which is now practically a camera, is stood on the ground and covered with a sheet of glass, which must touch the surface of the water, so that air does not come between—this preventing ripples. Very interesting vertical pictures may
be made with the apparatus. To work horizon tally (in the manner in which a fish would observe things through the sides of an aquarium), a watertight box is made, with an opening in one end. A piece of looking-glass is then taken, and a pinhole is made in the film of amalgam on the back, the glass being then cemented over the opening in the box with the unsilvered side out ward. In the dark room, a plate is inserted, the box filled with water and the cover replaced. A little more water is added, through a small hole provided for the purpose, in order to dis place any air that is present. Some remarkable results are obtained with this camera, which will photograph objects close to the tripod, besides those nearly due right and left, and directly overhead. Naturally, there is a certain amount of distortion, especially at the margins of the view.
(Fr., Cone de Poisson ; Ger., Fischleim) The product obtained by boiling fish-skins and other waste remaining from fish-curing, and manufactured principally at Gloucester, Mass., U.S.A. The glue thus procured is permanently liquid, and in a more or less viscous form. It is largely used by photo-engravers for the enamel, enameline, or fish-glue process, but for this pur pose it is clarified by boiling with albumen. The glue is preserved with oil of wintergreen.