An amateur photographer insists that a timing clock in the darkroom is a needless luxury. In order to time printing exposures, which he does with a pendant tungsten light under a reflecting shade, he simply fastens the electric-light cord so that the lamp and shade will act like a pendulum bob which beats the seconds. Of course he makes no effort to be exact, but if the distance between the lamp and the point of suspension of the cord be about 39 or 40 in., the beats will be very nearly seconds. When the light is turned on, it is started swinging, and the operator can thus easily count seconds with sufficient accuracy, and, besides, it readily furnishes a guide for duplicating printing results.
The same principle can be applied to camera exposures, if so desired, by the following plan. Select some suitable place on the under side of the tripod plate, as, for instance, the screw head, and fasten a small string, having a weight attached to it about 39 in. from the point of support. Like the swinging lamp, this device too, will beat seconds. For convenience, one of the tripod legs may be marked to indicate the length of string needed, so that the operator at any time can quickly fasten a string, measure off the right length on the tripod leg, attach a bunch of keys, a knife, or any other convenient weight, even a small stone, and have a second-beating pendulum for time exposures.—Contributed by F. B. Lambert, Chicago.
Supports for Camp-Fire Utensils
The sketch shows how to make a standard or support to hold cooking utensils over a camp fire. The main part or stake is made of a piece of gas pipe, on one end of which is turned an ordinary coupling, Fig. 1. This is used to furnish a strong head when the stake is driven into the ground. The rings and supports for the utensils are made of heavy wire bent into the shape required to hold the respective vessels. The sketch, Fig. 2, shows the manner of shaping the wires.
A Piece of Gas Pipe Constitutes the Standard with Wires Attached for Holding the Utensils (Fig. 1, Fig. 2)
A Rotary Tuning Coil
The rotary tuner shown in the sketch was designed by a correspondent of Modern Electrics. The circle is cut from 3/4-in. stock, 1 in. wide and well covered with insulating material. It is then wound with No. 24 single cotton-covered copper wire so that the coils will lie flat. All the arms are of 1/4-in. square brass. The supports are smaller in section. Sliders are mounted on the ends of the long arms and are kept in place by setscrews.
