— "^■^•t !■'- I' " 



Figure 28. — Wheatstone's automatic tel- 

 egraph, a, Top view of tape perforator; 

 b, side view of ta pe perforator; c, receiver; 

 d, diagram of the transmitter tape sensor, 

 which controlled the direction of the 

 current in the telegraph line. From 

 W. H. Preece and J. Sivewright, Teleg- 

 raphy, New York, 1876, pp. 117, 119, 122. 



Down Line ^ 



repeat the signal from one 10-mile circuit to the next. 

 He was fortunate in his choice of a confidant, for 

 Gale was familiar with Henry's work on electro- 

 magnets and spent the summer and fall of 1 837 modi- 

 fying Morse's electromagnet and battery so that 

 they corresponded with Henry's devices. By Septem- 

 ber 2, 1837, Gale could signal through 1,700 feet of 

 wire; by September 27, through one-half mile of 

 wire; by October 24, through 3)^ miles of wire; and 

 by November 13, through the desired 10 miles of 

 wire. 



A chance visit to Morse on September 2, 1837, by 

 a young man named Alfred Vail ^* made it possible 



28 Franklin L. Pope, "The American Inventors of the Tel- 

 egraph. With Special References to the Services of Alfred 

 Vail," The Century Illustrated Monthly Magazine, April 1888, 

 vol. 13, pp. 924-944; "Invention of the Electro-Magnetic 

 Telegraph," Electrical World, 1895, vol. 26, pp. 71-73, 105- 



for Morse to submit a proposal for a telegraph to 

 the Government. Vail was fascinated by Morse's 

 instrument and by Morse's idea for a relay to be used 

 in conjunction with it. On September 23, Vail 

 agreed to construct at his own expense a telegraph 

 based upon Morse's design that was to be ready on 

 January 1, 1838. For bearing the cost of patenting 

 the invention, Vail obtained a share in it, thereby 

 joining Gale who also had an interest in it. On Sep- 

 tember 27, 1837, Morse wrote to the Secretary of 

 the Treasury explaining the advantages of his new 

 means of telegraphy, and the following day applied 

 for a caveat that was eranted on October 3, 1837. 



108, 129-132, 153-156, 181-185. (Articles and letters written 

 by the sons of Morse and Vail also appear in this volume of 

 Electrical World. Each comments on the relative contribution 

 of his father to the invention of the telegraph.) 



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