336 HENRY AND THE TELEGEAPH. 



baildiiig illustrations by Profossor Hcury of liis results iu electro-magnetism. He saw 

 here a wire of great length, through which Professor Henry transmitted a cnnent of 

 galvanic electricity, and nuide the current to exert its power in ringing a boll at the 

 extremity of the wire. This was certainly the first establishment of the iiracticability 

 of the magnetic telegraph." 



" Professor Henry stated that he felt gratified at this iiublic recognition of his early 

 labors and discoveries iu reference to the electric telegraph." * 



Henry's primitive electro-magnetic telegraph (as already stated) was jiroperly an 

 acoustic telegraph. Morse's subsequent electro-magnetic telegraph was a recording tel- 

 eoraph, and it was this feature of automatic register which was always regarded by 

 its inventor as the most characteristic and important element of his invention. " It 

 was soon discovered, after the i ntroduction of the Morse system of telegraph, that words 

 could be read by the click of the magnet ; but paper was used upon which the arbitrary 

 alphabet of dots aud lines was indented by the instruments, for all matters of business 

 tip to 1852, and by many lines even later; but at the present time there is scarcely an 

 ofiice of any importance in the United States where the paper is used to receive the 

 record. Ten years ago the practice was almost invariable in the principal offices to 

 employ an operator to read the dispatch from the long strips of paper as it came from 

 the instrument ; and a copyist who stood by his side took it down. Now the system is 

 entirely changed. The operator reads by the click, and copies the message himself. 

 By this means the expense is lessened nearly one-half, and the risk of errors in a far 

 greater ratio."t To which it may be added, that the diminished duty of the armature 

 enables a single circuit to be operated through double the distance practicable with 

 the Morse recorder. 



And thus it has come to pass that the Morse telegraph to-day, is (by reversion to a 

 more primitive type) essentially an acoustic telegr(q)h.t So that "the click of the 

 telegraph heard all over this continent," is in Dr. Meads's expressive phrase, function- 

 alhj and in truth "but the echo of that little bell which first sounded in that upper 

 room of the Albany Academy." 



NOTE F. (From p. 296.) 



henry's relation to the ENGLISH TELEGRAPH. 



In consequence of the repeated disagreements between the English patentees, Messra, 

 Cooke and Wheatstone, (not long after their procurement of a joint patent in June, 

 1837,) as to their respective .shares of originality and credit iu the invention of the 

 needle telegraph, "Articles of Agreement" were drawn up ou the IGth of November, 

 1840, for the submission of their grounds of claim aud of dissatisfaction, to the arbi- 

 trament of two referees. Marc Isambard Brunei, on the part of Mr. Cooke, and John 

 Frederick Daniell, on the part of Mr. Wheatstone. And in December of 1840, the 



* Trans, of Albany Institute, vol. iv, "Proceedings," p. 245. 



t Prescott's History of Electric Telegraph, Boston, 1860, chap, v, pp. 92-93. To the same 

 effect is the statement in his later work : " In the larger telegraph offices of the United 

 States and Canada, the recording instrument, or register, is entirely dispensed with, 

 aud all comnumications are read by the sound made by the armature lever as it vibrates 

 between the upper and lower stops." (Prescott's Electricity and the Electric Teleg^-ajyh, 

 New York, 1877, chap, xxx, p. 435.) 



t Numerous patents have been granted for "sounders," having for their object the 

 emphasizing or re-enforcement of the sound from the receiving key or armature 

 impacts. Prescott, in his recent work, s])eaking of Thomson's ingenious and extremely 

 delicate "siphon recorder," remarks: " It is somewhat curious that in the progress of 

 telegraphic improvement, Morse's telegraph (the most valuable feature of which orig- 

 inally was considered to be its capacity for recording communications) should have 

 been modified in practice into an acoustic semaphore, while Cooke's telegraph (origi- 

 nally a semai>hore) should at length have been also modified into a recording instrument." 

 {Electricity and the Electric Telegraph, chap, xxxii, p. 561.) 



