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. 



