This section is from the book "Complete Self-Instructing Library Of Practical Photography", by J. B. Schriever. Also available from Amazon: Complete Self-Instructing Library Of Practical Photography.
Flashlight Equipment. Our illustration of this equipment shows how simple and portable is the whole device, and how well adapted it is to be taken to customers' residences when required. The extension support of the lamp is formed by three sections of telescoping brass pipes, which provide the necessary elevation of the lamp for the various kinds of pictures. The battery box itself forms the base and is amply stable for this purpose. This disposition also simplifies the wiring. The larger view of the camera and the battery box plainly show this in detail. The switch plate is attached to the outside of the Reflex camera and carries two binding posts, each one of which is connected with one of the wires of the two-wire cable, the other ends being spliced on wires connecting the lamp with the battery. (See Illustration No. 46.)
Construction Of Flashpan. The flashpan of the lamp (See Fig. 1, Illustration No. 47) is made preferably from a thin piece of slate (B), about 7 inches long, 2 inches wide, and as thick as an ordinary school slate. A 1/2-inch hole (C) is drilled in the middle, and on either side of this hole a flat strip of thin German silver (A, A), 5/16" wide and 1/32" thick, is held against the under side of the flashpan, by means of screws (D, D), which serve at the same time as the binding posts for the electric wires. A metal or wooden socket (E) is also attached to the underside of the flashpan, permitting of its being attached on top of the telescopic stand. In case this socket is of metal, care should be taken to keep it free from contact with the binding posts and springs, to prevent short circuiting.
The Fuse. The fuse is made from a thin piece of mica, l"x 1 1/2" (F, Fig. 1, of Illustration No. 47). In the middle of the short sides a small incision is made with scissors or pocket-knife, and a piece of thin German silver wire 3-1000" in diameter and 2" long is laid over this mica, the ends projecting equally on both sides (G, G), and then bent back and under against the mica plate, thus forming a double-ended hook which cannot slip out of position. The fuse so prepared is slipped in between the springs (A, A) and the flashpan (B), so that the wire (G) appears through the middle of the opening (C).
Electric Current. The current is provided by a battery of six ordinary dry cells. For convenience sake they are placed in a suitable wooden box, with binding posts on the lid, which also carries an ordinary circuit breaker or switch. The cells are to be connected in series. The switch is not absolutely essential, but is desirable as an extra safety device, being left open until all preparations are completed, and closed only just before the picture is focused.
Release For Making Exposure. The equipment is finally completed by constructing and attaching a special circuit breaker to the release button of the Reflex camera. A view of this is shown in Figure 2 of Illustration No. 47. The base (J) is a piece of vulcanite or other suitable insulating material. The two rods H and I are pivoted to the vulcanite piece, by means of the binding posts D, D, which latter thus serve two purposes - a pivot for the rods and connecting posts for the electric wires. The ends of the rods at K are kept separated by means of the coil spring E. The upper rod H is further held in position by the little pin L, while the lower rod I is kept from being forced upward by means of the pin L'. The spring G, which is wound around the pin F, keeps the rod I in constant contact with the pin L'; so when the upper rod is forced downward by pressure on the button A, there will be instant contact at the point K. A is the shutter release button on the Reflex camera, and when this is pushed downward to make the exposure, it comes in contact with the projection B, which latter is fastened securely into the rod H. This circuit breaker should be covered, as shown in Illustration No. 46, so the mechanism will not be disarranged.