Page:Popular Science Monthly Volume 91.djvu/798

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782

��Popular Science Monthly

��To Keep the Ends of Rafters from Spreading

IT frequently happens that ridge boards show a tendency to spread at the mitered joint. When they do, it is usually difficult to draw them and keep them together with nails. Even if they have been Galvanized drawn together iron strip they may spread later under changed atmos- pheric condi- tions.

A simple, un- failing and per- manent way to cure this defect is to take a strip

of galvanized sheet iron i3^ or 2 in. wide and from 18 in. to 2 ft. long, depending on the size of the ridge boards, and nail it over the top of the joint as shown in the sketch. Care should be taken to make it fit tight. This can be accomplished by nailing one side fast, then bending and hammering the other end down and pulling it by skewing some of the nails. It will be found that the boards can be drawn to- gether tighter this way than by merely spiking them together.

���A strip of metal used to tighten rafter ends

��Making a Substantial Cardboard Pulley for Belts

TURN two metal washers of the re- quired diameter, having the center hole a tight fit on the shaft. Cut out enough cardboard disks to make the pulley of the required width. Soak these disks in hot beeswax and place them on the

���A number of cardboard disks clamped between metal washers to make a pulley

shaft between the two washers. After carefully squaring them with the shaft, clamp them tightly together with three screw-clamps. Between the clamps drill three rivet holes. Rivet together as tightly

��as possible, leaving the clamps in place until all three rivets are in. After removing the clamps place three more rivets between the first three. The set-screw is made by screwing a wood-screw .into a previously drilled hole.

While the beeswax is not absolutely necessary it aids greatly in solidifying the pulley and affords an excellent grip to the belt. — Frank L. Matter.

��An Insulator and Fire Protector for a Stovepipe

RECENTLY when cutting through a stone wall preparatory to running a stovepipe, I found the pipe would be too close to a wood stud. Being without the proper chimney-pot, I made one from a small flower pot.

I first made a saw cut all the way around, as in Fig. 1, then smeared the edge with cement, as in Fig. 2, and placed it in

����FIG 2 FIG.3

A flower pot used to make an insulator for a stovepipe passing through a wall

the opening as in Fig. 3. To cut a pot like this it is better to use a grindstone instead of a saw. There is much less chance of the pot breaking. — James M. Kane.

��A Solution for Electro-Plating with Aluminum

DISSOLVE any desired quantity of an aluminum salt, such as the sulphate, acetate, or nitrate, in distilled water and concentrate these solutions to twenty Baume in a suitable vessel to hold the arti- cles to be plated.

The battery to be used should be three pairs of Bunsen cells with the wires coupled up for intensity and an anode of aluminum attached to the negative wires. The solu- tion should be slightly acidulated with its approximate acid heated to 140 deg. F. and kept at that temperature during the operation. — Herman Neuhaus.

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