** A Small Electric Motor [214]

The drawing herewith shows a simple electric motor which can be easily constructed by any boy who is at all handy with tools.  I made this motor

[Illustration:  Electro-Magnet Motor]

many times when a boy and can say that if carefully constructed it will run with greater rapidity than the more expensive ones.

A common magnet which can be purchased at any toy store is used.  The one shown is 3-1/2 in. in length.  The armature core is a strip of 1/16 by 1/4-in. iron, 2-1/4 in. long, bent U-shaped and fastened to the wood flywheel.  Each leg of the armature is wound with 10 ft. of No. 24 gauge magnet wire.  The commutator is made from an old 22 cartridge filed into two equal parts, each being a half circle, both of which are made fast to a collar on the shaft E. Each half of the commutator must be insulated from the other half.  The collar can be made by wrapping paper around the shaft until the required size is obtained.

The top end of the shaft runs in a hole bored in a brass support, B, which is screwed on the end of a piece of wood mortised in the base, as shown in Fig. 1.  The lower end of the shaft runs in a glass bead, D, which is fastened to a small piece of brass with sealing wax.  The small brass piece is fastened to the base with screws.  The bead should not have an eye larger in diameter than the shaft.  The shaft is made from an old discarded knitting needle.  The brushes are fastened to each side of the upright piece of wood supporting the brass bearing B.

The connections to the battery are shown in Fig. 2.  Each half of the commutator C is connected to the coils AA as shown in Fig. 1.  —­Contributed by J.M.  Shannon, Pasadena, Calif.

** Moving a Coin Under a Glass [214]

Place a penny or a dime on a tablecloth, towel or napkin and cover it over with a glass in such a way that the glass will rest upon two 25 or 50 cent pieces as shown in the sketch.  The coin is made to come forth without touching it or sliding a stick under the edge of the glass.  It is only necessary to claw the cloth near the glass with the nail of the forefinger.

[Illustration:  Removing the Coin]

The cloth will produce a movement that will slide the coin to the edge and from under the glass.

** Improving Phonograph Sound [214]

When playing loud and harsh records on a phonograph the music is often spoiled by the vibration of the metal horn.  This may be remedied by buckling a valise or shawl strap around the horn, near the center.

** How to Make Paper Balloons [215]

Balloons made spherical, or designed after the regular aeronaut’s hot-air balloon, are the best kind to make.  Those having an odd or unusual shape will not make good ascensions, and in most

[Illustration:  Paper Balloon; Pattern and Parts to Make Balloon]

cases the paper will catch fire from the torch and burn before they have flown very far.  The following description is for making a tissue-paper balloon about 6 ft. high.