Of course it is quite possible to buy the parts of a telephone ready made and fitted together, but it is much more interesting to construct the apparatus yourself.
The whole affair is so easily and cheaply made that no difficulty can possibly be experienced, and you have only to exercise care in order to succeed in constructing a very handy and interesting machine.
Fig. 1b.—Magnet case.
For the apparatus to be of any practical use, a pair of receivers are required—one for the person speaking, and the other for the person listening.
First of all purchase two bar-magnets, i.e. straight and magnetized at one end only—not the ordinary horse-shoe magnets. These bar-magnets should be about four inches long, and can be bought from any electrician; at the same time obtain from him an ounce of silk-covered wire, No. 36.
Before taking the magnets from the shop it would be as well to test them. This can be done by placing the marked end of one to the unmarked end of the other, and unless the former is able to support the weight of the latter, do not take either, but insist upon the electrician giving you stronger ones.
Having made your purchase, set to work upon the actual apparatus. The first things to be made are the wooden cases for the magnets, and these require care in construction.
From a straight broom-handle cut off two lengths, each a little longer than the magnets, i.e. about 41⁄2 inches long, and split them carefully down the middle with a chisel. Along the center of each of these halves cut a groove (B, [Fig. 1a]), in such a manner that when the two halves are put together they fit properly, and there is room for the magnet to slip backwards and forwards in the hole running through them. Now glue the parts together and you will have two short wooden tubes, or magnet cases, as shown in [Fig. 1b].