Page:Popular Science Monthly Volume 92.djvu/484

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Making Silver Contact Points for a Spark Coil

A GOOD way to make contact points for almost any kind of instrument is explained as follows: Procure a piece of carbon, such as is used in dry batteries, and drill a hole in the center of it the size desired for the contact. This hole is then filled with small strips of silver, procura- ble at a jeweler's shop. After the hole is filled with the loose silver, the carbon is placed in a fire and heated until the strips are all melted into one piece. Then the carbon is cooled and broken away, leaving a rod of silver, the right size for the contact. Such contacts 5/32 in. in diameter have been in use on a 2-in. spark coil for some time and they give satisfactory results. — Odis Reynolds.

��Electric Toaster to Operate on Dry Batteries

THIS home-made toaster can be used where no electric light current from a power house is obtainable, by employing either dry or wet batteries. Take a piece

��Insuloted copper, wire

��German silver wire

���Connecting wires

Heating element wound on mica for an electric stove to be run on battery current

of mica — isinglass from an old coal stove — and upon it wind about twelve turns of German silver wire. A good size for the mica plate will be 4 by 6 in.

To support the mica with its wire coil, cut out of K-in. hardwood, two pieces of the shape shown in the drawing, 8 in. wide at the base and 6 in. wide at the top. A height of about 8 in. will be right. These two pieces should be held 6 in. apart

��by means of two strips 6 in. long by 1 in. wide nailed on the ends. On the top, the mica is fastened with small tacks.

Drive medium sized nails into the wood at opposite corners of the mica plate, driving each only half way in. These will be convenient for holding the connecting wire. This should be insulated copper wire and should be connected with the German silver wire and to the batteries at either end.

When the current from two or more dry cells is turned on, the current will flow from the batteries, through the positive copper wire, through the German silver wire, back through the negative copper wire to the battery. The German silver wire has so much resistance that it will become red hot as the current passes. A slice of bread laid on the red hot w-ires will toast quickly. A trial test with the number of cells to be used will determine the size and length of wire that you will need.— F. E. Brimmer.

��German Wireless Plotting Muffled by Band Music

A GERMAN cruiser interned at Hono- lulu, relayed wireless messages from German agents in the United States to Japan, with the intention of embroiling the two countries in war. The wireless apparatus was worked while the ship's band played vigorously.

It appears that the former German Ambassador and his principal aids figured in the plot. The former German Consuls at Honolulu and Manila were also impli- cated. Both of these men pleaded guilty recently of participation in a plot to establish a revolutionary government in India.

A German secret agent, who was known by a number similar to a submarine, aided in the transmission of these messages, and advised the German government of the sailing time of vessels. The captain's diary reveals these secrets. After its discovery the captain was court-martialed and is now in solitary confinement pend- ing his removal to Fort Douglas, Utah.

In February, 1917, the Cruiser Geier was set afire by her crew and badly damaged. The vessel was towed to the Pacific Coast for repairs.

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