While, for use in shallow water, these boats are not built with a keel, one can be attached to prevent the boat from "sliding off" in a side wind or when turning around. When one is attached, it should be 3/4 in. thick, 3 in. wide, and about 8 ft. long.—Contributed by B. Francis Dashiell, Baltimore, Md.
An aniline color soluble in alcohol, by adding a little carbolic acid, will hold fast on celluloid.
Double-Swing Gate with Common Hinge
The Post and Gate are Cut Away Back of the Hinge to Allow the Latter to Swing Back
Ordinary hinges can be easily bent and so placed on posts that a gate can be swung in either direction. As shown in the illustration, hinges can be made to fit either round or square posts. The gate half of the hinge is fastened in the usual way. The post half is bent and so placed that the hinge pin will approximately be on a line between the centers of the posts. The gate and post should be beveled off to permit a full-open gateway.—Contributed by R. R. Schmitz, Birmingham, Ala.
Testing Out Induction Coils
While winding an induction coil, I found it necessary to test the sections for continuity. Having no galvanometer, I connected a battery and low-resistance telephone receiver in series with the section and battery. The battery and telephone receiver may also be used for testing out the secondary of an induction coil, to determine if it is burnt out.—Contributed by John M. Wells, Moosomin, Can.