THE PROOESSES OF PURE PHOTOGRAPHY.
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these instructions. We will, however, give one or two hints,. which we think may prove useful, whether" negative films" or "stripping films" are used in this roll-holder. Although _ the instrument itself registers on the paper the extremities of each exposure, it is well, whenever opportunity offerS-during a tour, for instance- to mark in pencil each end of the film as it presents itself when the shutter is withdrawn. This will form a further safeguard, beyond the small punched holes, against cutting up the film in the wrong places. (The necessity for this is much lessened in the new pattern.) When about to develop a spool of exposed films, the inexperienced will do well to cut off one exposure at a time, and develop one before he cuts off another. (The new pattern is vastly improved in this respect, also ; in fact, the new design is so superior, in almost every essential point, to the pattern originally introduced, that those who bought the original pattern have a distinct grievance, that, so 8oon after they had purchased one pattern, another so greatly superior l'hould be brought under their notice, and should excite their covetousness and tempt them to extravagance.) The exposed length of film for development, being cut off, is immersed in water face downwards for a few seconds, being slidden sideways, if possible, into the water ; after the few seconds have elapsed it is lifted face up and either brushed over with a broad hair brush under water, or pulled quickly along the face up under water. This is simply to prevent airbells. Development follows, then fixing, washing, clearing, washing again. Then the film is squeegeed face downwards to a polished sheet of vulcanite, where it is allowed to dry, and whence, when dry, it ought to strip off with ease, one corner being raised with a knife or other pointed instrument. According to the ~instructions, the negative should then be rendered translucent by the application of some oily lubricant, such as the "translucine," sold for the purpose. Against this oiling we protest. Printing truly is rendered more rapid, and "grain," possibly, may be slightly eliminated, but without special and highly inconvenient means the negatives so treated eannot be preserved for any considerable length of