Figure 22. — Wheatstone and Cooke's single-needle, double- 

 needle, and 5-needle telegraphs (left to right). From E. 

 Feyerabend, Der Telegraph von Gauss und Jl'eber, Berlin, 1933. 

 P- 75- 



Mechanization of the process of telegraphy brought 

 about the instrument that eventually came to domi- 

 nate those English telegraph lines where traffic 

 was heavy. In the dial and the needle telegraph 

 systems the speed of transmission depended on 

 the rapidity with which the transmitter could be 

 worked manually; further progress was made by re- 

 placing the manual key with Bain's paper tape. With 

 Wheatstone's "automatic fast speed printing instru- 

 ment" (fig. 28) of 1858 (British patent 1239, June 2, 

 1858), the operator first used a manual perforator to 

 punch holes in a stiff paper tape which was then 

 sent through a transmitter that was operated by this 

 tape. The receiver recorded the message produced 

 by this transmitter directly in the form of dots and 

 dashes. Later the Wheatstone receiver produced 

 punched tape similar to that used in the transmitter, 

 and this tape was used to operate a printing machine. 

 Depending upon the circuit, from 50 to 150 words 

 per minute could be sent by this method, which was 

 used in most English telegraph systems carrying heavy 

 traffic during the 19th century. 



Across the ocean in the New World, inventors 

 were also seeking to apply electricity to communi- 

 cation devices. The first inventor actually to 

 devise and set up an electric telegraph in the United 



States was Harrison G. Dyar.^" Sometime between 

 1826 and 1828 Dyar worked out an electrochemical 

 system whereby messages were recorded by sparks 

 passing through treated paper and discoloring it. 

 The dot and dash pattern formed by the discolorations 

 indicated the message. Dyar's telegraph was tried 

 out near a race track on Long Island by setting up 

 poles with insulators to carry the wire that formed 

 half the circuit and using the earth as a ground 

 return for the other half. However, an unscrupulous 

 partner, seeking a greater share in the expected gains, 

 forced Dyar to drop his invention. 



It was thus left to another American, Samuel F. B. 

 Morse, an inventor-painter, to patent a practical 

 electromagnetic system of telegraphy.-'' Instead 

 of basing the receiving instrument upon the torsion 

 of a needle in a galvanometer coil or upon electrolysis, 

 Morse based his telegraph on the direct pull of an 



26 .Mfred Munroe, Concord and the Telegraph, Concord Anti- 

 quarian Society, Concord, Massachusetts, n.d. (around 1902). 



2' Alfred Vail, The American Electro-Magnetic Telegraph: With 

 the Reports oj Congress, and a Description of all Telegraphs Known, 

 Employing Electricity or Galvanism, Philadelphia, 1845; United 

 States Reports, 1835, vol. 56, pp. 62-137; Samuel I. Prime, Life 

 of Samuel F. ,B. Morse, LL.D., Inventor of the Electro-Magnetic 

 Recording Telegraph, New York, 1875; Edward L. Morse, ed., 

 Samuel F. B. Morse — His Letters and Journals, New York, 1914, 

 2 vols.; Carleton Mabee, The American Leonardo: A Life of 

 Samuel F. B. Morse, New York, 1943. 



294 



BULLETIN 228: CONTRIBUTIONS FROM THE MUSEUM OF HISTORY AND TECHNOLOGY 



