Section III, 1891. [ 9 ] Trans. Rot. Soc. Canada. 



II. — Automatic and Multiplex Telegraphy. 

 By F. N. GisBORNE, CE., M.I.E.E. 



(Read May 27, 1891.) 



In a former paper upon " The Inception of Electrical Science and the Evolution of 

 Telegraphy " read in Section III of the Royal Society of Canada, and subsequently revised, 

 and published by the Canadian Society of Civil Engineers, the concluding paragraph read 

 as follows : 



" That the most successful and profitable telegraph companies of the future will abandon the 

 present system of a multiplicity of wires for the transmission of intelligence, and at business centres 

 and important stations, will employ female labour for perforating and comparing with the original 

 manuscript despatches, to be forwarded by automatic tiansmitters ; an additional wire being operated 

 by Morse sounders for the correction of errors, and also for the requirements of intermediate local 

 business, such additional wire being available for duplex, quadruplex or multiplex instruments." 



The foregoing conviction has been confirmed by late improvements both in automatic 

 and multiplex apparatus, whereby telegraphy can now compete profitably with the postal 

 systems in such long distance countries as Canada and the United States. 



Twenty-five cents for a ten-word message, exclusive of address and signature, does 

 not appear to be an excessive charge when the time saved is material, and when business 

 men have learned by experience how much information can be conveyed within such 

 limited number of words ; but to the uninitiated general public 100 words at the same 

 tariff" rate would be a great boon, and add materially to the volume of both commercial 

 and social inter-communication. 



The practical means by which such desirable result can be accomplished with profit 

 to investors may now be considered. 



Thousands of miles of poles and wire at a primary cost of millions of dollars for con- 

 struction and a vast outlay for maintenance and renewals can be dispensed with by the 

 adoption of automatic and multiplex telegraphy. By the former 1,000 words per minute 

 have been correctly transmitted, during stormy weather, between cities 1,000 miles apart ; 

 and by the latter one wire is utilized for a dozen distinct and parallel circuits. 



A skilful Morse operator transmits during a day of eight or nine working hours an 

 average of twenty-five words a minute, and by a Wheatstone automatic repeater 300 to 

 400 words can be sent over moderately long circuits ; but the latter apparatus reqitires 

 considerable auxiliary labour, as every dot and dash in each alphabetical letter has to be 

 stamped out separately prior to transmission per wire. 



Duplex, quadruplex and multiplex instruments require separate skilled operators for 

 each and every circuit utilized in such systems, so that the economy is limited to the 

 reduced number of wires, etc., between stations. 



Sec. Ill, 1891. 2. 



