Page:Popular Science Monthly Volume 92.djvu/331

 Popular Science Monthly

��A Telegraph Sounder Made from Old Bell Parts

THE sounder here illustrated is made entirely from an old bell, with the exception of only a few of the essential parts. The magnets on the bell are first

���Old bell parts mounted on wooden base with attachments to make a telegraph sounder

carefully removed and screwed to the base as shown. The soft iron armature is next removed and the spring attached to it is taken off. It is then soldered to a brass strip which is shown in the accompanying illustration at A, and fastened to the wooden support at B. The bridge, C, is constructed of brass, but a more ductile metal may be substituted if the brass can- not be worked with the materials at hand. To obtain the best results, a small ad- justable screw D is used to regulate the stroke of the armature. The drawing makes all other directions and construc- tions clear. — Herman Neuhaus.

��A Secret Code of Colors for Transmitting Messages

FOR Boy Scouts and others desiring to communicate by means of a secret code, the one described will prove very acceptable. The code is very simple, being composed of color combinations, each combination representing a single letter of the alphabet. Thus, it will be seen that- the combination, red and yellow (ry) represents the letter A; red and blue (rb) B, and so on.

In this manner, any message can be sent, with the assurance that only the person for whom it is intended, can read it. All the colors, which are used in the following code, can be obtained by buying an ordinary box of crayons.

In writing out a message, always leave a small space between each letter and a much larger one between words.

��31.5

The following code can be changed, as it is only an example.

R-rcd; y -yellow; b-blue; g-green; p-purple; o-orange; br-brown; bla-black.

��A-ry

B-rb

C-rg

D-rp

E-ro

F-rbr

G-r bla

H-yb

i-yg

��J-yp K-yo L-y br

M-y bla N-bg 0-bp P-bo Q-b br R-b bla

��S-gp

T-go

U-gbr

V-gbla

W-po

X-p br

Y-p bla

Z-obr

period-r

��Only Uncut Diamonds Are Used to Dress Emery Stones

DIAMONDS are used to sharpen and shape emery wheels. But even if anyone were so foolish as to use it, the diamond of the jewelry shop would not do the work well, for it is the natural face and edge of a diamond that does the cutting on such work. Therefore the polished stone of the engagement ring would be of little or no value as a stone dresser.

��Practicing the Telegraph Code Without a Battery

THE illustration shows how to con- nect phones with a key, so that sounds may be heard, similar to those produced in a radio transmitter. This plan cannot be used on direct current mains. It takes the pulsations of an alternating current to produce the effect. About 10 turns of No. 22 gage, single

��"PHONES

���LAMP 'CORO

��KtY I

WATER WORKS '^f'

Separate hook-up to an alternating current line for producing sounds like radio

cotton covered wire is wound around the drop cord, and when the lamp is turned on to get a flow of current, the hook-up is ready for practice. — E. T. Jones.

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