Page:Popular Science Monthly Volume 49.djvu/322

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complete nowadays unless it contains a complete set of photographic apparatus.

These are but a few among the many things that photography does for us. Each year reveals some fresh uses to which it can be placed.

Quite recently the electrician has discovered its value to him in many ways, principally in registering electrical discharges, so that the same may be carefully studied at leisure. At a meeting of the British Association in 1892, Mr. A. A. Campbell Swinton showed some most interesting photographs of electrical discharges which are here reproduced (Figs. 1 and 2). According to an account of them given in the Electrical Review, these figures were

PSM V49 D322 A positive discharge.jpg
Fig. 1.—A Positive Discharge.

all obtained without the employment of a camera or lens, but produced by merely causing the electrical discharges to take place across the sensitive surface of an ordinary photographic dry