CEKT.IIX l-.ICrORS .IIFF.CTIXG TEl.F.C.K.ll'll Sl't-.l-.l) 3i7 



A briff analysis of what are the fuiulami-nt.il features of these 

 systems will be given and, based on the results which have been de- 

 velojx'd in the preceding discussion, comparison will be made of thei^C 

 systems with systenis based on other principles. A jiarticular effort 

 will be made to dear up what appears to be fundamentally incorrect 

 assumptions which underlie the arguments which ha\e been advanced 

 in favor of these "sine wave" systems. 



Crehore-Sqiiier System. The use of a sine wase en\elope to im- 

 prove the characteristics of telegraph signals was advocated by Crehore 

 and Squier.* The words "I'nited Stales" formed by means of a 

 wave of this type are shown in Fig. 3</. The code employed is the 

 same as the ordinary Continental Morse, the only difference being 

 that the signal elements consist of half-cycle sine waves. 



In what has preceded, it has been shown that a half-cycle sine 

 wave has a smaller area than a rectangular wave rounded off by pass- 

 ing through an electrical network and, consequently, the sine wave 

 is inferior to the latter from the standpoint of the received signals. 

 From the standpoint of interference into other circuits, it has also 

 lieen pointed out that the half-cycle sine waves contain more high- 

 frequency components than properly rounded off rectangular waves. 

 Consequently more interference into other circuits will be produced 

 with the wave made up of signal elements consisting of half-cycle 

 sine waves. 



Sqitier System Applied to Submarine Cables. A more recent sug- 

 gestion of Squier * gives the wave shown in Fig. 3a. This wave 

 resembles the one advocated by Crehore and Squier in that each 

 signal element consists of a half-cycle sine wa\e. As has been pointed 

 out, there is no advantage gained by this. 



The difference between the two systems lies in the fact that the 

 wa\e in Fig. 3a uses three absolute values and crosses the axis once 

 every half cycle. The code is the same as the Continental, a space 

 being indicated by a half-cycle sine wave of one unit am[)litude, a dot 

 by a half-cycle sine wave of two units amplitude and a dash by a 

 half-cycle sine wave of three units amplitude. 



By referring to the figure, it will be seen that the resulting wave 

 resembles a continuous sine wave, except for the fact that successive 

 half cycles differ in magnitude. For this reasf)n, the code ma>' be 

 termed an "unbroken-reversals" code. 



In considering the application of this code to submarine cable 

 telegraphy, it is convenient to make use of an analysis which is carried 



' Crehore and Squier, loc. cit. 



' Squier, loc. cit. Proc. Phyi. Soc. 



