HENRY AND THE TELEGRAPH. 357 



omitting a specific date, the space for the day and the month having been left blank. 

 The applicant having been informed of this by official letter dated May 20, 1840, a new 

 affidavit, properly executed, was sent to' the Patent Office May 29, 1840, and the pat- 

 ent was finally issued Juno 20, 1840. 



Whether the true date of the invention of the ''relay," by Professor Morse, be 1837, 

 or 1838, is not regarded as a matter of any importance historically, as in either case, 

 he is fully credited with its original conception. 



NOTE L. (From p. 325.) 



ALPHABETIC BINARY NOTATION. 



It seems proper to take some notice of the growth of that beautiful invention, the 

 bi-sigual alphabet. Its origin appears to be considerably earlier than that of its con- 

 gener, the binary arithmetical notation devised by Leibnitz two hundred years ago. 

 An alphabetic code of signals is indeed as old as the time of the Greek historian Poly- 

 bius (1.^0 years before the Christian era), who describes in the tenth book of his Gen- 

 eral History a method of signaling to a distance any required dispatch by means of 

 torches, — which he says was invented by Cleoseuus and Democlitus, and perfected by 

 himself. In this scheme the Greek alphabet of 24 letters is distributed into five series 

 or tablets, each comprising five letters: (the last space being vacant.) Then torches 

 (from one to five) exposed on the left side, will indicate the group or tablet ; and sim- 

 ilar torches raised on the right side, will indicate the place of the letter on the tablet.* 

 This system may obviously be very easily resolved into a bi-signal alphabet. It ap- 

 pears that the emperor Leo VI, (of the eastern division of the empire) about the year 

 A. D. 900, in a chapter of his "Military Tactics," on naval warfare, described a plan 

 somewhat similar to the above, t 



An early English example of the bi-signal alphabet is to be found in Francis Bacon's 

 "Advancement of Learning," published in 1605. In this Treatise, discoursing on cryp, 

 tography, he observes : "We shall here annex a cipher of our own, that we devised at 

 Paris in our youth. . . . The invention is this : let all the letters of the alphabet be 

 resolved into two only, by repetition and transposition; for a transiiosition of two let- 

 ters through five places or different arrangements, will denote two-and-thirty differences, 

 and consequently fewer or four-and-twenty, — the number of letters in our alphabet." 

 (It will be remembered that at this date the letters j and u had not been differentiated 

 from I and V.) Bacon then gives an example of " a bi-literal alphabet" consisting of 

 the permutations of " a" and " b " through five places ; and he subjoins the comment 

 that "this contrivance shows a method of expressing and signifying one's mind to any 

 distance, by objects that are either visible or audible, provided the objects are capable 

 of two differences, as bells, speaking-trumpets, fire-works, cannon, &c."t 



Inthe" Cyclopaedia" of Doctor Abraham Rees, published early in the present century 

 (1802-1819), under the word "cipher" are presented among a variety of interesting 

 alphabetic notations, exami)les of one formed by the combinations of three characters, 

 and of one formed by two characters ; the latter evidently copied from Bacon. The 

 compiler says: "Another mode of corresponding by cipher is striking two, or three- 

 bells of various sizes." After remarking that two symbols require a larger combina- 

 tion for each letter than three, and giving an example of each kind, the writer adds: 

 ' ' The effect will be the same, whether the writer make use of arithme tical characters, 

 letters, dots, lines, mathematical diagrams, or any other sign which admits of two, or of 

 three differences." Employing as an instance the figures 1 and 2, he makes use of 

 five recurrences for each letter, as in the example given by Bacon, and he follows a 



* Polybius's History ; lib. x. cap. 45. Greek and Latin edition of A. F. Didot, Paris, 

 8vo. 1852. pp. 474, 475. 



t"The emperor Leo VI, in his chapter on naval tactics (chap, xix), describes almost ex- 

 actly Myer's army code, concluding with the remark, ' as the ancients did.' " {Johnson's 

 Universal Cyclopwdia; edited by Dr. Barnard: art. "Naval Signals," vol. iii. p. 734.) 



t On the Dignity and Advancement of Learning, book vi, chap. i. — Bolm's edition, 1858, 

 pp. 222, 223. 



