when ready for printing, a positive or transparency is made from it in the same manner as a lantern slide or window transparency, says the Sketch, London.  Use the same size plate as the negative for the transparency.  To make the print in relief place the positive in the frame first with the film side out and the negative on top of this with the film side up in the usual manner.  Put in the paper and print.  This will require a greater length of time than with the ordinary negative on account of printing through double glass and films.  In using printing-out papers care should be taken to place the printing frame in the same position and angle after each examination.

** Wireless Tip [431]

Place the transmitting instruments of a wireless outfit as close together as possible.

** How to Make a Wireless Telephone [432]

A noted French scientist, Bourbouze, was able to keep up communication with the outside during the

[Illustration:  Details of Wireless Phone Installation]

siege of Paris by making practical application of the earth currents.  The distance covered is said to have been about 30 miles.  Another scientist was able to telephone through the earth without the aid of wires.  Nothing, however, has been made public as to how this was accomplished.

It is my object to unveil the mystery and to render this field accessible to others, at least to a certain degree, for I have by no means completed my researches in this particular work.

In order to establish a wireless communication between two points we need first of all a hole or well in the ground at each point.  In my experiments I was unable to get a deep well, but the instruments worked fine for a distance of 200 ft., using wells about 25 ft. deep.  As in ordinary telephone lines, we require a transmitter and receiver at each point.  These must be of the long-distance type.  If a hole is dug or a well is found suitable for the purpose, a copper wire is hung in the opening, allowing the end to touch the bottom.  To make the proper contact an oval or round—­but not pointed—­copper plate is attached to the end of the wire.  If a well is used, it is necessary to have a waterproof cable for the part running through the water.  The top end is attached to the telephone transmitter and receiver, as in the ordinary telephone, to the batteries and to a zinc plate, which is to be buried in the earth a few feet away from the well or hole, and not more than 1 ft. under the surface.  A battery of four dry cells is used at each station.

Both stations are connected in the same way, as shown in the sketch.  This makes it possible for neighbors to use their wells as a means of communication with each other.  —­Contributed by A. E. Joerin.

** Eyelets for Belts [432]

If eyelets, such as used in shoes, are put into the lace holes of a belt, the belt will last much longer.  The eyelets, which may be taken from old shoes, will prevent the lace from tearing out.  I have used this method on several kinds of belts, always with entire satisfaction.  —­Contributed by Irl R. Hicks.