Page:Popular Science Monthly Volume 92.djvu/492

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��Popular Science Monthly

��end. Make a right angle bend at the other end 'j^i in. long, and drill it to take the handle. The handle should be large and substantial. It is best to buy it from some supply house.

Now you are ready to assemble the jaw chps. Clean all the clips and the blade with fine emery cloth before assembling. Lay the bottom clip in position on the bakelite block; next the spacer and then the top cUp. Fasten all three securely to the block by means of three No. 10/32 machine screws, and lock the screws with acorn nuts. Assemble the screw which acts as a stop for the blade, and pinch the ends of the clips together, so the jaws will grip the blade firmly. The hinge clip is assembled in a similar manner. Fasten all three blocks to the marble base with the 5/16-in.-18 screws. Put a brass washer and a felt washer on each screw, in the order named, before assembling. Fasten the blade in the hinge clip with a 3^-in.-20 brass screw, and lock it with a 3<^-in.-20 brass nut.

The next thing to do is to mount the switch. If you mount it in an exposed position, protect it with a weatherproof box. Place the switch so that the hinge clip is uppermost; and fasten the aerial wire to this. The lead-in to the apparatus and a No. 4 ground wire go to the two jaw clips respectively. Space the switch from the wall or support upon which you mount it, by means of three wooden blocks, about 1 J^ in. by 1 J^ in. and 1 in. thick. Drill a J^-in. hole in each of the blocks; pass the three mounting screws through these and the base, turn them up tightly, and your switch is then ready for use. — W. H. Scheer, Jr.

��Killing Woodchucks with Deadly Dynamite Fumes

WOODCHUCKS may be easily ex- terminated by the slow burning of dynamite in the burrows. The kind of dynamite to use is the low grade ammonia. A stick of this, well saturated with kero- sene, will smolder and give off a deadly gas, which when confined in the burrows, will asphyxiate any of the animals con- tained in them. After placing and igniting the stick, cover up the entrance to the hole tightly so that no air can penetrate or gas escape.

��A Few Tips on Splicing Fuse for Discharging Dynamite

THE proper way to cut a fuse in order to splice it to another piece of the same kind or to splice a fast burning fuse to one that is slow burning is shown in Fig. 1. The fast burning fuse is usually fastened in the cap or detonator. The powder surfaces are placed together and lashed tight.

The proper way of slicing the fuse when two charges are to be exploded simultane- ously from one main fuse is shown in Fig. 2. The diagonal cuts are used to

���Splicing fuse to ignite a charge of dynamite. Double splices for branches in fuse line

give greater powder surface and to insure the fire traveling from one piece to the other.

The detonator cap for a powder fuse is shown in Fig. 3. Fig. 4 shows the de- tonator cap for an electric exploder, while Fig. 5 shows the method of splicing fuses which simultaneously explode several charges — each dot in the drawing indi- cating a splice.

A method of connecting the charges when they are to be fired with an electric exploder is shown in Fig. 6. All wires are securely fastened to the charge to which they are attached and the ends are spliced together as shown in Fig. 7. The lead-in wires should never be connected with the exploder until everything is ready for the shot. — Geo. M. Petersen.

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