TELEGRAPH. 



fmokc or fire, or firing of guns, may, if it i3 a large number, 

 be liable to miftake, a learned profeffor in Germany propofed 

 to (horten the numbers employed, by ufmg a quaternary 

 inftead of the decenary arithmetic. Thus, according to his 

 fyftem, the units were to be placed as in common arithmetic ; 

 a figure in the next place, to the left hand, inftead of denot- 

 ing the number of tens, was a niHltiple of 4, denoted by the 

 figure, that is, it denoted the number of fours to be exprefTed ; 

 in the third place, the figure denoted the number of fixteens 

 inftead of hundreds ; and the fourth place of figures would 

 be fixty-fours inftead of thoufands ; and fo on. £. gr. To 

 write down 95, he placed his figures thus: 1133 ; the 3 

 in the place of units denoted 3, the next 3 denoted 

 3 X 4, or 1 2 ; the third figure, i , denoted 4 x 4, or 1 6 ; the 

 next figure, I, denoted 4 x 4 x 4, or64; confequently 1133, 

 in the quaternary arithmetic, was equivalent to 64 + 16 + 

 12 4- 5 =: or ill the common decimal numeration. The 



advantage propofed by thus changing the figures was, that 

 in making the fignals 95, there muft be fourteen firings, or 

 appearances of fmoke, which, in the other mode, is done by 

 eight firings. In this arithmetic, a greater number than four 

 never appears ; and there is kfs danger in mifcouiiting fo 

 fmall a number. Some of the numbers in the diftionary muit 

 be devoted to the fingle letters of the alphabet, as it is by 

 means of them alone that proper names can be made out. 



Mr. Edgeworth, who, we believe, firft introduced the nu- 

 meral fyftem of communication, gives the following account 

 of its advantages, in point of fecrecy, over the alphabetical 

 method, which is a great objeft in telegraphic communication. 

 Although the alphabet may be varied at pleafure, and any 

 arbitrary figns employed, yet thefe are poffible to be deci- 

 phered by rules which depend upon the ufual arrangements 

 of letters : thus, for inftance, a fingle charafter being exhi- 

 bited as a word, muft, in the Englilh language, be either A 

 or I. The proportion which exifts between the number of 

 words of one, two, three, or any greater number of letters, 

 can be clafted in catalogues, and from thefe the monofylla- 

 bles of any cipher are eafily obtained ; and from the letters 

 of thefe monofyllables, the letters of longer words are dif- 

 covered. By fimilar rules, fome of which are very ingenious, 

 and depend upon the phllofophy of language, any alph.ibetical 

 cipher may be eafily unfolded. (See Cipher. ) But thefe 

 rules, excepting a few of them, are ufelefs, when ciphers 

 are employed to denote entire words ; and the moft obvious 

 mode of difcover)' may be avoided, by omitting thofe common 

 words which occur fo frequently in every lajiguage, as ihe, 

 and, that, to, &c. ; and even fuppofing that, from its frequent 

 recurrence, any word ftiould be difcovered, no progrefs can 

 be made from fuch data, for the cipher of any word is an 

 ifolated fa£l which leads to nothing farther. 



Suppofe the knowledge of any particular vocabulary ftiould 

 fall into hands for which it was not intended, a flight change 

 in the numeration, without any aftual change of the figures, 

 would prevent difcovery : for inftance, fuppofe it is fettled 

 between the parties, that 6, or any other number, is to be 

 added or fubtraftcd from the numbers which are exhibited 

 before referring them to tlie vocabulary. The advocates of 

 the numeral fyftem ftate, that a letter can be communicated 

 much quicker by fignals which exprefs words, than by fig- 

 nals which exprefs only letters. Words may be forwarded 

 as faft as they can be looked out in a didlionary, and even 

 fafter, whilft only an equal number of letters could have been 

 communicated by the alphabetical mode. Another alleged 

 advantage refulting from the ufe of words in the telegraphic 

 correfpondence is, that the words of the fame meaning in 

 different languages having the fame number attached to each, 

 a correfpondence could be carried on from one language into 



9 



another, which, though not grammatically corrttt, yet would 

 be fufficif^tly intelligible. Proper names muft be fpell, 

 which may eafily be done, every letter having a correfpond- 

 ing number. , ' 



Mr. Richard Lovel Edgeworth, in the Tranfaftions of the 

 Royal Society of Ireland, vol. vi. p. 125, has delcribed his 

 telegraph, which is fimple, and admits of very numerous com- 

 binations : it \', intended to reprefent numbers to which words 

 may be referred. 



The machinery confifts of four indices or pointers, each 

 capable of revolving on a centre or axis, fo as to affume dif- 

 ferent pofitions. The ftiape of each pointer is that of an 

 ifofceles triangle, of wliich the bafe is rather lefs than half the 

 perpendicular. The four pointers are placed in a row, as 

 jhewn hy Jig. 12, and, as in common numeration, the right 

 hand reprefents units ; the fecond from the right, tens ; the 

 third, hundreds ; and the fourth, thoufands. It is eafy to 

 diftinguifti whether a hand moving vertically, points perpt-n- 

 dicularly downwards or upwards, horizontally to the right or 

 left, or to any of the four intermediate fituations : tliis pro- 

 duces eight pofitions, which can be made by each pointer ; 

 but of thefe eight pofitions, feven only are employed to de- 

 note figures ; the upright pofition of the hand or pointer 

 being referved to repreicnt o, or zero. The figures thus in- 

 dicated refer to a vocabulary, in which all the words are 

 numbered. Telegraphs of this kind, which are to be fixed 

 at.permanent ftations, which may be feen clearly with tolerable 

 glaflijs at twenty miles diftance, are to be mounted on ftonc 

 or wooden pillars, fixteen or twenty feet high ; four of which 

 muft be folidly erefted in a row ; and on the top of each a 

 moveable circle or platform turns horizontally upon a centi'e, 

 in the manner of a moveable windmill head. Acrofs the plat- 

 form an axis lies horizontally, and carries the arm or pointer, 

 fixed vertically at one extremity of the axis, whilft, at the 

 other end, are eight handles to turn the pointer round by. 

 The handles are fixed in their different pofitions by a catch or 

 alidad. By means of the platform, the pointer may be turned 

 to any part of the compafs ; and as one fide of it is painted 

 black, and the other white, either fide may be employed, as 

 the colour of the clouds, or the fituation of the place, may 

 require. 



In managing a correfpondence by thefe machines, it is 

 neceflary to have certain fignals eftabliftied ; nor are thefe 

 fignals merely arbitrary ; it is abfolutely neceflary that they 

 {hould be made by the two external pointers of the row, viz.. 

 units and thoufands ; or by the two internal pointers, i-i-z. 

 tens and hundreds ; elfe they could not be repeated by the 

 intermediate ftations without confitfion ; becaufe,in the middle 

 ftations, that pointer which reprefents thoufands, when con- 

 veying a meiTageeaft wards for inftance, muft, when an anfwer 

 is returned to an oppofite direftion, reprefent un-its. The fame 

 change will take place between the pointer that denotes 

 hundreds and tens. 



When any com.munication is to be commenced, the 

 pointers that denote thoufands and units are to be whirled 

 round till the fame is done at the correfponding ftation. 

 When this fignal has been anfwered, the perfon wlio gave it 

 proceeds to fend his intelligence. As foon as he begins, the 

 pointer of hundreds at the oppofite ftation is turned to 2, 

 and kept in that pofition till the word is made out from the 

 vocabulary ; the pointer is then turned round to o, or zero. 

 The perfon who is fpeaking, when he perceives by this 

 fignal that he is underftood, turns all the machines to o, 

 which is always to be done at the end of every word. 



Wiien aU his machines are in this pofition, his correfpondent 

 again turns his pointer belonging to the place of hundreds 

 to 2, to ftiew that he is ready to receive tl»e intelligence, and 



it 



