322 HENRY AND THE TELEGRAPH. 



century later, Dr. Gale states that "Before lines of telegraph were set 

 up, it was anticipated that in long lines the ordinary current of 

 electricity might not be strong enough to work the magnet at such dis- 

 tance, so as to write, but would be so strong as to open and close a side 

 or local circuit, as suggested by Professor Henry. This mode of using 

 one electric circuit and magnet to open and close another electric circuit 

 (either for extending the main circuit to greater distances or to operate 

 any local circuit), although not in the machine when I first saw it, was 

 discussed in an early part of 1837, before any lines had been constructed."* 



In both these accounts. Professor Gale has intidvertently (though not 

 unnaturally) confounded together two entirely distinct inventions, in- 

 volving different arrangements and puri)oses; — the "relay" circuit and 

 magnet (of the " intensity" order), and the " receiving " circuit and mag- 

 net (of the "quantity" order); although Professor Morse himself dis- 

 tinctly declared he had no conception of the latter arrangement in 1837, 

 having invented it " in May of 1814." 



While the first invention of the special application called the "relay" 

 is thus unhesitatingly ascribed to Professor Morse, the practically much 

 more important arrangement of the terminal or local short circuit " quan- 

 tity " magnet for reinforcing the power of the " intensity " magnet, must 

 as unhesitatingly be claimed for Henry ; and as an invention several 

 years prior to that of Morse, it would by the well-known principles of 

 patent-law, have generically subordinated the special application of the 

 latter. Although Ilenry did not technically "perfect the invention," it 

 remains none the less true that every "receiving magnet "in use through- 

 out our own and other countries is but the obvious application of Hen- 

 ry's exi)erimental junction of the two circuits, exhibited eleven years 

 before it entered into Professor Morse's patent of April 11, 181(). 



As indicative of the relative importance of these two inventions, — the 

 Henry "receiving" magnet and the Morse "relay" of circuits, it may 

 be stated that on the extended lines of the " Western Union Telegraph 

 Companj^," there are now 13,745 of the former in actual operation, and 

 only 228 of the latter; being 60 of the Henry " receivers" for each of 

 the Morse " repeaters." And in remarkable confirmation of Henry's 

 early anticipations of the capacitj' of his "intensity" magnet to be 

 operated under judicious conditions directly through a distance of sev- 

 eral hundred miles, it is the "accomplished fact" to-day that numerous 

 single circuits ranging from 500 to COO miles in length, are in actual use 

 in the United States, operated by his magnet. The telegraph-line from 

 New York to New Orleans, (upward of 1,500 miles,) is worked in three 

 links or circuits (connected by tivo relays or repeaters) ; the last circuit, 

 from Chattanooga, Tenn. to New Orleans, La. being G38 miles long, t 



* Memorial of S. F. B. Morse, Wasliington, 1875, p. 19. On the question of the date 

 of Professor Morse's "Relay", sec "Supiilement," Note K. 



t These interesting facts are conimnnicatotl by the accomplished telegraphic expert, 

 Mr Frank L. Pope (of the Western Union Telegraph Company), a vice-president of the 

 American Electrical Society: author of "Modern Practice of the Electric Telegraph:" 



