PRECAUTIONS IN DRYING.
Negatives are usually dried by standing them in a grooved wooden, metal, or ponce lain rack. Patterns of these have bee already illustrated. A porcelain rack (Fig 206) is a useful acquisition, taking up little room and being also available for washing, by standing it with the nega tives in any suitable receptacle. Dryinr should take place in a fairly warm atmo sphere, free from dust. It is the practic of sonic photographers, in fine weather, to stand the racks outside in the open air. This certainly promotes rapid drying, bu dust and grit are apt to collect on the film. A good plan is to enclose the rack in muslin or gauze cover, after the style a meat-cooler ; this will effectually prevent the deposition of dust. A drying box on this principle is now obtainable, and is a great convenience. In doubtful or weather, the best place for the rack con-' taining the plates is on the perfect and speedy removal of the dis solved hypo. An ingenious device, after the fashion of a water-wheel, is shown by Fig. 203. As will be seen, a negative is placed in each division and water directed through the opening at the top, causing the wheel to rotate under a steady spray.
Another arrangement, which explains it self, is illustrated by Fig. 204. Large nega tives are generally placed in a dish under the tap. A combined rose and filtering arrangement is now obtainable, to fit any tap, and is a great convenience for this and other photographic purposes (see Fig. 205). Films are best washed in a rather deep dish, emulsion side downward, if cut ; over a fire. Negatives may be rapidly dried by draining off the surplus water, and immersing them for five minutes in methylated spirit. They are then drained, pressed lightly between two pieces of clean, white blotting-paper, and placed near a current of air, or at a. short distance from a fire, where they will dry in a surprisingly short time. When a negative is taken out of the washing tank, in any circumstances, it should be gently rubbed with a tuft of cotton-wool and rinsed under the tap, for the purpose of removing any surface deposit or grit which has collected on the film. This would be an objection able feature when the negative was dry.