954 



Popular Science Monthly 



Interesting Method of Learning 

 the Telegraph Code 



IN learning either of the telegraph codes 

 one finds it easy enough to learn to 

 transmit correctly without the aid of 



Fig. I 



■■A<^A<^ 



A metal ball rolling in V-shaped notches 

 having alternate contacts and insulation 



any other person, but, when it is desired 

 to learn to receive, it becomes abso- 

 lutely necessary either to have a teacher 

 or some kind of apparatus to take his 

 place. There are very few students who 

 can afford the services of a teacher and 

 consequently the majority must secure 

 some sort of mechanical device to make 

 the signals. There are several of these 

 devices on the market but as a rule the 

 price is a good deal beyond reach. Fur- 

 thermore, in these mechanical transmit- 

 ters there is not enough of the element 

 of chance; that is, when one has used one 

 of these instruments for a short time he 

 gets used to the combinations employed 

 to such an extent that the instrument 

 loses its usefulness. 



In learning the code quickly it is 

 absolutely necessary that one never know 

 what letter is coming next and it was to 

 provide an arrangement in which the 

 element of chance enters that the ap- 

 paratus herewith described was developed. 



Reference to Fig. 1 will serve to give 

 an idea of the method used. The princi- 

 ple in use is to provide a V-shaped trough, 

 for a metal ball to roll in, and to cover 

 the sides of the trough with metal pads 

 »o arranged as to correspond to the 

 telegraph signals. When the ball is 

 caused to roll over the signals it makes 

 corresponding contacts and a buzzer 

 or sounder repeats them. 



Thus in Fig. 1, A is a baseboard and 

 BB are metal angles fastened to the 

 board so as to form troughs, CC, be- 



tween them. In each trough is glued 

 pieces of paper or other insulation bent 

 at right angles, as at EE, so arranged 

 along the length of the trough as to form 

 the signals. The arrangement of the 

 parts is clearly shown in the view. Fig. 2, 

 which is a corner of the apparatus with 

 the cover and the front removed. It 

 will be seen that there is provided one 

 trough for each letter and numeral of the 

 telegraph alphabet and the insulating 

 pieces are pasted in to correspond to the 

 characters forming each letter. The 

 author uses forty characters; 26 for the 

 letters, 9 for the numerals and 5 for 

 punctuation marks, etc. 



A cover for the box is to be made 

 of wood or cardboard so that the ball will 

 be prevented (when the cover is on) from 

 jumping from one groove to another. 



The simplest method of using the ap- 

 paratus is to take it up with the two 

 hands with the cover on and by tilting 

 the box to cause the ball to roll back and 

 forth through first one groove and then 

 another, thus producing signals at ran- 

 dom. It will be evident after a little 

 thought that signals will be produced 

 with this form of the apparatus only when 

 the ball rolls in one direction for all 

 letters except those which are symmetri- 

 cally arranged, as for instance, D, E, 



The ball may roll into any one of the 

 notches without the operators' knowledge 



etc. It will be evident to anyone with 

 the ability to build the apparatus that a 

 passage could be provided for the return 

 of the ball so that meaningless signals 

 would be prevented and also that a 

 pivoted frame might be constructed so 



