Photography, as a rule, necessitates a dark room or cabinet, and many preparations as we all know—a “messing” about with chemicals and considerable practice before we can become proficient; so it is not surprising that few amateurs take to it—they prefer to purchase the pictures. But in the new apparatus of which we are speaking, the glass plates are already prepared to receive the image. It is not at all necessary for the operator to stain his fingers and knuckles and nails with nitrate of silver, or any other “chemicals” whatever. He just inserts the plate in the Scenograph, and then his apparatus being steadily set up, he removes the covering from the lens. To develop the image (in the dusk of the evening or by candle-light) it is necessary to put some drops of ammonia in a saucer, breathe upon the plate so as to soften the collodion, and hold it above the ammonia, and then, under the influence of the vapour, the picture will appear. After this simple operation the picture will be found fixed for a lengthened period—practically indefinitely. Thus on the return of the pedestrian he can reproduce, at small expense, a whole series of little pictures faithfully representing his holiday tour. The illustration shows a small apparatus by which on thin plates small photographs can be taken and fixed till it is found desirable to enlarge them. The _Photophone_, one of the most recent contributions to science, is an instrument which, in combination with the telephone principle, makes it possible to convey sounds by means of a ray of light, and by means of a quivering beam “to produce articulate speech at a distance. The success of the Photophone depends upon a rare element, selenium, which has its “electrical resistance” affected by light. Professor Adams demonstrated that the resistance of selenium was reduced just in proportion as the intensity of the light which was acting upon it. Here was the key to the Photophone as thought out by Professor Bell. He fancied that he might by means of his telephone produce sound if he could vary the intensity of the beam of light upon the selenium, which he connected with his telephone and battery.