_The German Ica cameras._ These are larger editions of the light wood hand camera already described, but with the addition of a Bowden-wire shutter release. The body of the larger cameras carries a distinctive feature in the distance control of the lens diafram, worked by means of a lever which actuates racks, pinions and connecting rods leading to the lens. On the side of the camera body a shallow box is provided for carrying the color filter in its bayonet joint mount to fit on the lens (Figs. 42 and 43). [Illustration: FIG. 42.—German aerial cameras.] [Illustration: FIG. 43.—Diagram of German 50 centimeter camera.] [Illustration: FIG. 44.—U. S. hand-operated aerial camera (type M) with 10 and 20 inch cones.] _The hand-operated bag-magazine camera_ of the United States Air Service (Type M) is similar to the small hand-held camera, but differs in three respects: a removable shutter (of the variable-tension fixed-aperture type) embodying an auxiliary curtain for capping during the setting operation; a Bowden-wire shutter release; and the employment of a set of standard interchangeable cones to hold lenses of several focal lengths. The 20 inch and 10 inch cones are shown in Fig. 44. The operation of this camera is similar to the French standard cameras, but not so simple because of the number of motions required in manipulating the bag. Its chief objection for war work lies in fact in the magazine, which should be superseded by a two-compartment or other satisfactory type of plate changing chamber. The camera alone, with 20 inch cone, weighs approximately 40 pounds; the loaded magazine, with its plates in metal sheaths, 15 pounds. [Illustration: FIG. 45.—English C type aerial camera.] _The English C and E type cameras._ The C and E type cameras have now chiefly an historic interest. They were the first used in the English service, fixed to the fuselage, and were later used in training work in England and in the United States. They were never built for plates larger than 4 × 5 inch nor for lenses of more than 12 inch focus, a limitation set by the lenses available at the time of their design. [Illustration: FIG. 46.—English type “E” hand-operated plate camera.]