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26 THE PHOTOGRAPHIC NEWS. [JANVARY 9, 1885. I propose to show you this evening two methods of enlarging on gelatine paper—namely, the slow and the rapid process, and to illustrate these with three different kinds of apparatus. The slow method involves the use of the most simple apparatus, which is generally at hand and within the means of the amateur. The camera and lens which he uses, attached to a box of wood or metal arranged to exclude the light of a lamp held therein, are the principal instruments required, the wall of any room answering for a screen to hold the paper. The ground-glass frame of the camera is replaced by a frame which holds the negative to be enlarged, and a piece of ground glass is suspended or held between the negative and the lamp, for the purpose of diffusing the light and equally illuminating the negative. A reflector, secured behind the lamp in the box, is also advisable. The light being intercepted by a pane of ground glass sub stitute, is considerably weakened in its actinic power while passing through the negative and lens, hence a long exposure is required ; with a negative clear in the shadows and showing con siderable contrast, I usually give from ten to twenty minutes. Much depends on the size of the enlargement; if it is to be made life-size, a long exposure will be necessary; if one-third life-size, the shorter time will be right. Because of the weak light thrown upon the screen, I found it was sometimes difficult to obtain an accurate focus by reflection of the image on a white card ; hence, I discovered that the use of a ground glass, in place of the white card aided very materially in obtaining a correct focus, arranged so that the operator could stand and view the image as it was transmitted through the glass. I have constructed a special focussing-board embodying this feature. You will notice I have a horizontal board which rests upon a table, sliding upon this is a hinged frame, which supports DEACu’s ESLARGIXG APPARATUS at its upper end a pivoted board revolving wheel, like in a vertical plane. The board is made twice the length of the frame, and at one end is inserted, flush with its face, a sheet of ground glass. The operation is exceedingly simple. To focus, the ground- glass end of the board is turned down, and the whole is moved backward or forward from behind until the image appears sharp, when the board is revolved or reversed until the solid end is down. The paper is next put in place, and the enlargement proceeded with. The paper, being in the same plane as that occupied by 1 the ground glass, is always in focus. THZ REVOLVING GROUND GLASS AND PAPER HOLDER, On another table I have fixed a stand, which supports the camera (an ordinary 4 by 5 mahogany camera). The folding bed has been removed to permit the close approach of the lamp to the rear of the camera. On a frame, made to take the place of the ground glass, is the negative film, side toward the lens. Behind the negative is suspended the ground glass, and close to the latter is the lamp enclosed in a metal box, arranged with shielded openings, to allow free access of air. X have an excessively tall chimney to the box, in order to promote a strong current of air and prevent the lamp from smoking. I found the chimney in valuable where a long exposure was necessary, and would suggest to Mr. Carbutt and other makers of developing lamps, that a tall, telescopic chimney, arranged to be easily attached, would add immensely to their utility, and avoid the annoyance so frequently met with of a smoky lamp while in the midst of the development of a valuable negative. Behind the lamp, in the box, is arranged a reflector. The rear frame of the camera is secured to the wood side pieces of the stand by two metal buttons ; the forward part of the camera can, therefore, be moved away from, or toward, the negative, and it is this movement which controls the size of
