William Slyke.

I have here attempted to describe an instrument or rather a scientific novelty, with which I believe many an evening can be passed pleasantly by the readers of Amateur Work. It is certainly a simple instrument and costs less than a dollar to make. It is what might be called "An Electric Questioner." The first thing needed for such an instrument is a box about 15" long, 61/2" wide and 3" deep, the wood of which should not be more than 1/2" thick. Draw a straight line across the center of the box. On one side of the line will be the questions, on the other the answers. Procure 36 ordinary wire shingle nails. Nail 18 of the nails on one side of the line and 18 on the other side, having the heads of the nails on the inside of the box, and the points sticking through the top of the box. Do not drive the heads of the nails tight against the top, but leave a small space between the top of the box and the head of the nail, as in Fig. 1. When all the nails have been put in, get about 20 feet of cotton-covered magnet wire about No. 20 gauge and cut it into lengths of about 14". Remove the insulation for about

1" from each end. From the heads of each of the 18 nails on the question side wind the end of one of the lengths of wire and bring it to any one of the heads of the nails on the answer side of the box. Do the same with each nail, as shown in Fig. 2. Only a few are shown in the illustration, to avoid confusion.

Figure 1.

Figure 2.

Figure 3.

When all the wires are attached, the nails can be hammered all the way in. When completed, the inside of the box will be a network of wires. Now get an electric bell, or, better still, a buzzer, as a bell makes too much noise. Screw the buzzer to the edge of the box in the center, as shown at A, Fig. 4.

Two handles or electrotudes should then be made. These can be made by cutting a piece of wood round about 21/2" long and 1/2" thick. Drive a long wire nail through the wood so as to protrude through the other end an inch, as shown in Fig. 3. The wooden handles used by provision dealers for bundles will serve nicely. Solder a piece of flexible insulated copper wire about 1/ long to the head of the nail A, Fig. 3. Do the same with the other handle, and connect the other ends of the wires as follows: Screw the end of the wire attached to one of the handles to the binding-post on the buzzer, screwing it on very tight. The other handle should be screwed to the binding-post of a "dry battery." From the other binding-post of the battery attach a piece of wire, and bring it to the remaining binding-post on the buzzer. (See Fig. 4.)

Figure 4.

Now test the working of the instruments. Take one of the handles and hold the metal tip to any of the nails of the 18 on the question side. Take the other handle and tap each of the 18 on the answer side until the buzzer sounds. Do the same way with each of the nails. If your instruments work thus far, you are sure of success.

The next and last thing is to make the cards on which are the questions and answers. Get a sheet of white cardboard that is not too stiff, and cut it the size of the top of the box. The width is taken from the end of the box up to the buzzer, but not covering it. Put dots on the cardboard where each nail strikes, and punch holes where each dot is. Now push it over the nails until it reaches the top of the box. Print or write below one of the "question nails" a question, riddle or conundrum. Hold one of the handles to the nail which has the question ; take the other handle and tap the answering nails until the buzzer sounds, then write the answer below that nail. Do the same with all the nails, until one side of the card is filled with questions and the other side with the answers. To work this instrument, you put a card over the nails, take a handle and hold it on the nail which has the question you want answered. Take the other handle and tap the answering nails until the buzzer sounds. You then read the answer to the question. If the instrument is made right, and the insulation of the wires in the box unbroken, you will always get the correct answer. Of course the instrument can be made larger or smaller to suit the taste of the maker. The battery may be put inside the box and a bottom nailed on to prevent it from falling out. This instrument will be found both practical and entertaining. Additional cards can be made with many instructive questions in United States history, geography, or with conundrums, etc. If the nails are all driven in straight, the cards can be put on or removed without difficulty.