Submarine Telegraphy. 115 



SUBMARINE TELEGRAPHY. 



BY EICHAED BITHELL, B.SC, PH.D. 



No attentive observer could spend an hour in the examination 

 of any of the commonly-used electric telegraphs without dis- 

 covering* that there were three distinct parts of the apparatus 

 on which the engineer is called upon to direct his energies, 

 and which in turn may task his highest skill. These parts 

 are — 



I. A "battery — voltaic or magnetic — as a source of electric 

 power. 



II. Conducting wires — by means of which the electric 

 fluid is conveyed from one spot to another more or less distant. 



III. Instruments — that is, pieces of apparatus ; by means 

 of which the action of the fluid on the conducting wire may be 

 made evident to the eye or ear. 



Every telegraphic system contains these three parts, and 

 each in turn has been an object of the electrician's profoundest 

 study and most earnest solicitude. In all cases the first of 

 these parts is a matter of primary importance, and in the in- 

 fancy of telegraphic science much difficulty was felt in securing 

 batteries of sufficient power and constancy — the latter quality 

 being essential to the proper working of the system. Owing 

 to the amount of attention and experience which have been 

 brought to bear on this part of the apparatus, batteries of 

 various kinds have been devised, which answer their purposes 

 sufficiently well to meet all the requirements of telegraphy in 

 its present stage of development. In the transmission of 

 currents over long distances however, and especially in marine 

 telegraphy, great difficulties are met with in the construction 

 of the second part of the system, namely, the conducting wires 

 — difficulties so great as to offer a wide field of improvement 

 to those whose business or taste may lead them to engage in 

 the study. But in the organization of central stations, and 

 especially in such as have to transmit or receive messages in 

 great number, the third part rises into importance, and the 

 question is how to construct instruments which shall commu- 

 nicate signs to the ear and eye with the greatest promptitude, 

 rapidity, and precision. In the observation and consideration 

 of any form of telegraph, therefore, it will be necessary to 

 glance at each of these three portions of the apparatus, while 

 one or the other may claim in turn a greater amount of atten- 

 tion, according to the purpose to which the telegraph is to be 

 applied, or the special object which we have in view. 



Telegraphs are commonly, though rather loosely, designated 



