A very handy combination knife and meat saw can be made of an old discarded saw blade. The blade is cut on a line parallel with the toothed edge, allowing enough material to make a good-sized blade, then the straight part is ground to a knife edge and a wood handle attached at one end. The handle is made in halves, placed one on each side of the blade, and riveted together, then the projecting metal is ground off to the shape of the handle.—Contributed by A. C. Westby, Porter, Minn.
The Blade of the Knife is Cut from the Toothed Side of a Discarded Saw Blade
Clamp Used as a Vise
A carpenter's wood clamp fastened to the edge of a bench, as shown in the sketch, makes a good substitute for a vise for many kinds of light work. If the clamp is located over or in front of the bench post, holes must be bored in the latter to admit the ends of the clamp screws. A hole is bored through the shoulder screw and a handle attached as shown.—Contributed by H. W. J. Langletz, Harrisburg, Pa.
The Clamp Attached to a Bench Top will Serve the Purpose of a Vise in Many Instances
Wire Expansion Meter
When there is a current of electricity in an electrical conductor a certain amount of heat is generated due to the opposition or resistance of the conductor to the free passage of the electricity through it. The heat thus generated causes a change in the temperature of the conductor and as a result there will be a change in its length, it contracting with a decrease in temperature and expanding with an increase in temperature. The temperature of the conductor will change when the current in it changes, and hence its length will change, and it will reach a constant temperature or a constant length when the current in it is constant in value and the rate at which it is giving off heat is exactly equal to the rate at which heat is being generated in it.