This Neat Wireless Detector was Made of Materials Easily Gathered in the Boy’s Workshop
A cheap and serviceable wireless detector was made from odds and ends such as any amateur can obtain. The base was made of wood, saturated in paraffin. The mineral cup is a brass cap from a cartridge fuse. The upright was made of a piece of copper, ¹⁄₂ by 4¹⁄₂ in. long, and is fastened to the base by an old-battery binding post. The spring which supports the cat whisker is made of a strip of copper, ¹⁄₃₂ in. by ³⁄₁₆ in. wide. The cat whisker is soldered to the spring, and the spring is bolted to the upright. The setscrew, which regulates the pressure of the cat whisker upon the mineral, works in a nut, soldered over a hole in the top of the upright. The cat whisker is made of No. 22 gauge bare copper wire. The connection between the cup and the battery binding post, at the front edge, is made on the under side of the base.—Charles Brinkmann, Chicago, Ill.
A Wire-Screen Pincushion
Pins Placed in This Durable Desk Pincushion Arrange Themselves in Vertical Position, Head Up
Pins placed in a pincushion like that shown automatically arrange themselves vertically, head up, so that they may be removed handily when needed. The pincushion is durable, and a useful device for the desk. It is made by binding two layers of ordinary screen wire between wooden frames, mounted on a wooden base, ¹⁄₄ in. thick, 2¹⁄₂ in. wide, and 3¹⁄₂ in. long. The frame can be finished neatly, and made of hard wood to match other desk fittings.—D. J. McKean, San Francisco, Calif.
Straightening Sheets of Paper
When a sheet of paper, a drawing, or a blueprint becomes curved or warped, it is annoying to use the sheet unless it is straightened. An easy method of doing this is to lay the sheet flat on the edge of a drawing board or table and draw it down over the edge, the hand pressing down on the paper, stretching it out. This, repeated several times, will soon smooth a much-curled sheet.
Emergency Tension Weight Used on Typewriter
If the band that draws the typewriter carriage should break, the operator can continue to write until proper repairs are made by a temporary substitute for the spring tension. Tie a string to the carriage, where it will not become entangled in the mechanism, and attach a weight, about equal to the pull of the spring, to the string. Let the weight hang over the edge of the desk, to the left of the machine. It will pull the carriage along, as does the usual tension device.