_The standard Italian camera and similar types._ The camera (Lamperti) which the Italian Air Service used almost exclusively during the war exemplifies a type quite different from anything as yet described (Figs. 48 and 49). Plates to the number of twenty-four (13 × 18 cm.) are loaded into a chamber at the top of the camera. Each plate is held in a septum furnished with projecting lugs at one end. A lever acting through a Bowden wire, exposes the bottom plate, which then swings downward about these lugs as pivots, and is forced by a pair of fingers into a compartment at the side. The between-the-lens shutter has a single speed of 1/150 second, and variation of exposure is achieved by altering the lens aperture. [Illustration: FIG. 48.—Various plate changing devices.] The great advantage of this camera is its simplicity, a single motion performing all the operations. Its disadvantages are its dependence on gravity for operation, its between-the-lens shutter, the limitation set to the number of exposures, and the necessity for removing the whole camera to take out the plates for developing. In actual practice the camera has worked out well. The better light found in the Italian as contrasted with the northern theatre of war makes the between-the-lens shutter at high speed adequate, while the limitation to the number of exposures has been met by carrying several complete cameras in each plane. Because of the Bowden-wire operation these cameras need not be accessible to the observer or pilot, so that the practice of carrying them in single-seaters was common. Attempts at standardization of Allied practice through the adoption of standard lens cones were, of course, out of the question with this camera. With its limitations of shutter efficiency and plate size it is doubtful whether it would have been satisfactory outside the service for which it was developed. [Illustration: FIG. 49.—Italian (Lamperti) single-motion plate camera, on anti-vibration tray.] The limitations set by the between-the-lens shutter in this type have been overcome in an experimental camera along similar lines made by the Premo Works of the Eastman Kodak Company, and in the French Aubry model (Fig. 48). These employ focal-plane shutters which swing out of the way and are set as the exposed plate swings or drops to the receiving chamber. The dependence on gravity in this type could doubtless be avoided by positive finger mechanisms. If so, the resultant cameras, set and exposed by a single motion, would acquire a highly desirable simplicity of operation. They would have peculiar merit because of the very short interval required between exposures—a characteristic needed for making low stereo-oblique views. The cameras just mentioned have, however, departed far in form from the lines of standardized practice and have not been followed up. CHAPTER IX SEMI-AUTOMATIC AERIAL PLATE CAMERAS