A small pouch, sliding by 2 loops upon the strap of the larger pouch, containing 1 mirror bar. A skeleton leather case containing 2 tripods. [Illustration: FIG. 1.--Heliograph assembled.] The mirrors are each 4½-inch squares of plate glass supported by sheet brass and cardboard backings, and mounted in brass retaining frames. At the center of each mirror there is an unsilvered spot three thirty-seconds of an inch in diameter and holes corresponding to these spots are drilled in the backing. The sun mirror differs from the station mirror only in that it has a paper disk pasted upon its face covering the unsilvered spot. The mirror frames are carried by brass supports provided at the bases with conical projections accurately turned to fit the sockets of the mirror bar and grooved at the ends to receive the clamping spring. Each support is fitted with a tangent screw and worm wheel attachment functioned to control the motion of the mirror frame about its horizontal axis. [Illustration: FIG. 2.--Mirror and mirror bar case.] The mirror bar is a bronze casting provided at the center with a clamp threaded to fit the screw of the tripod. By releasing the clamp the bar may be moved independently of the screw and adjusted to any desired position. Conical sockets for the reception of the mirror supports are provided at the ends of the mirror bar. These sockets work freely in the bar and, being actuated by a tangent screw and worm wheel, serve to regulate the motion of the mirror frame about its vertical axis. Clamp springs, for engaging and securing the ends of the mirror frame supports, are attached at each end of the bar. The screen is a brass frame 6½ inches square, in which six segments or leaves are mounted in such a way as to form a shutter. The leaves are designed to turn through arcs of 90° on horizontal axes, unanimity of movement being secured by connections made with a common crank bar. The crank bar is operated by a key and retractile spring which serve to reveal and cut off the flash. A set screw and check nut at the lower edge of the screen frame limits the motion of the crank bar and the opening of the leaves. A threaded base support furnishes the means of attaching the screen frame to the tripod. The sighting rod is a brass rod 6½ inches long, carrying at the upper end a front sight and a movable disk. About the rod is fitted a movable bronze collar, coned and grooved to take the socket and clamping spring of the mirror bar. A milled edged bronze washer serves to clamp the collar to the rod at any desired point. [Illustration: FIG. 3.--Heliograph tripods.] The tripods are similar in all respects, the screw of either threading into the mirror bar or screen frame. Each tripod is provided with a hook at the base of the head, allowing the suspension of a weight when great stability is required.