TELEGRAPH. 



ariful contrivance, to tranfmit thaughts m a peculiar lan- 

 auaee from one diftance to another, by means of machines, 

 which arc placed at different dillanccs of from twelve 

 to fifteen miles afunder, fo that the expreffion reaches a very 

 diftaiu place in the fpace of a few minutes. This is now 

 brought to fuch a (late of perfeftion, that a correfpondence 

 may be conduded with Liflc, upon every fubjeft and every 

 thing : even proper names can be cxpreffed ; an anfwer may 

 be received ; and the correfpondence thus be renewed feveral 

 times a day. The only thing which can interrupt their 

 cffeft is the weather, when the air is fo very bad and turbid 

 that the objcifts and fignals cannot be diftinguidied. By this 

 invention, remotenefs and diftance almoft difappear, and all 

 the communications of correfpondence are effefted with the 

 rapidity of the twinkhng of an eye. By its aid the opera- 

 tions of government can be very much facilitated, and the 

 unity of the republic confolidated much more by the fpeedy 

 communications with all its parts. 



" The greateft advantage can be derived from this mode of 

 correfpondence, becaufe, if thought proper, its objects need 

 only be made known to certain individuals, or to one indi- 

 vidual alone, or to the extremities of any diftance ; fo that 

 the Committee of Public Welfare may at prefent carry on a 

 correfpondence with the reprefentative of the people at Lifle, 

 without any other perfons being acquainted with their ob- 

 jefts. If Lifle was even befieged, we fhould know every 

 thing at Paris that might happen in that place, and could 

 fend thither the decrees of the Convention without the 

 enemy being apprifed of it, or able to prevent it." 



M. Chappe's or^he French telegraph is reprefented in^^. 4, 

 which ii made from fome fketches taken from the telegraph 

 »n the palace of the Louvre, at the time of its firft eftablifti- 

 ment, and publifticd in the Monthly Magazine, and other 

 publications. 



A B is a beam or ftrong maft of wood, erefted perpen- 

 dicularly from the centre of a cabin or fmall houfe fituated 

 on a rifing ground: it muft be about 15 or 16 feet high 

 above the top of the houfe. C D is a balance-beam, jointed 

 to the top of the maft, fo as to be moveable on its centre, 

 like a fcale-beam. This balance-beam, which is called the 

 long indicator, may be placed vertically or horizontally, or 

 any how inclined, by means of ftrong cords, which are at- 

 tached to the central wheel or pulley D , which has two grooves 

 in the edge to receive the cords. The long indicator is about 

 1 1 or 12 feet long, and 9 inches in breadth ; and at each 

 extremity it carries fecondary indicators F, G, which like- 

 wife turn upon centres or joints, by means of four cords, 

 which are condufted through a hollow in the centre pin or 

 axis of motion of the long indicator, otherwife the motion of 

 the long indicator to put it into different pofitions, would 

 derange the cords, and alter the direftion of the fecondary 

 indicators, which are capable of being placed in any pofition 

 with refpeft to the long indicator, by thofe cords being con- 

 di;fted by puUies down into the cabin, and there attached to 

 Other mechanifm, by means of which the whole machine is 

 moved, and can be made to affume any of the pofitions re- 

 prefented by the fmall figures in the plate, in which pofi- 

 tions it forms a variety of different charafters, to denote the 

 letters of the alphabet or numerals. 



That the indicators may be very light, and at the fame 

 time oppofe the leaft refiftance to the wind, they are formed 

 by frames, the interior parts of which are filled up by fmall 

 oblique and feparate boards, which however, being feen in 

 front, appear contiguous. The ends of the fmall indicators 

 are carried beyond the centres, and carty counter -weights to 

 balance the weight of the indicators ; but thefe ends and 

 balances are made fo as to be invifible at a diftance. 



It is eafy to find the number of fignals polTible to be 

 made with this telegraph : for if we confider the great indi- 

 cator as being fixed, we (hall find that each of the fmaller 

 ones may diftinftly take five different pofitions : two where 

 it makes a right angle wiih the great indicator ; two where 

 it makes an angle of 45° ; and one where it falls back upon 

 the great one, in which cafe it will difappear. Three other 

 diftinft pofitions might alfo be created ; one where the fmall 

 indicator would be Horizontal with the great one, and two 

 where it would make an angle of 135° with it. 



The leffer indicators then, confidered as fingle movers, 

 will furniffi five times five, or twenty-five fignals. As the 

 great indicator is alfo a mover, there are twenty-five times as 

 many fignals as this indicator has diftinft pofitions ; and as 

 it has but four diftinft pofitions, one horizontal, one ver- 

 tical, and two inclined, there are in all four times twenty-five, 

 or one hundred fignals. 



The manner of ufing the telegraph was as follows : At the 

 firft ftation, which was on the roof of the principal pavilion 

 of the Louvre at Paris, M. Chappe, the inventor, received 

 in writing, from the Committee of Public Welfare, the words 

 to be fent to Lifle, near which the French army was at that 

 time ftationed. Each of the telegraphs in the line employed 

 three perfons to work it : one to move the machine, which 

 was done by a fingle motion of a winch, and could there- 

 fore be effefted in a moment. A fecond perfon was em- 

 ployed with a telefcope to obferve the telegraphs of the two 

 adjacent ftations, to receive the communications, and to know- 

 by their fignals, if they had underftood the communication 

 made to them, and alfo to receive the anfwers. The third 

 perfon was employed to write down the obfervations made 

 by the fecond perfon, and to give orders to the firft. The 

 ftations were about three or four leagues diftant, and an 

 obfervatory was fituated near the Committee of Public 

 Safety at Belleville, to obferve the laft telegraph. 



The grammarian will eafily conceive that iixteen figns may 

 amply l"upply all the letters of the alphabet ; fince fome 

 letters may be omitted, not only without detriment, but with 

 advantage. Thefe figns, as they were arbitrary, could be 

 changed every week : fo that the fign for B one day, might be 

 the fign for M the next ; and it was only neceffary that the 

 perfons at the extremities ffiould know the key. The intei^- 

 mediate operators were only inftrufted generally in imitating 

 and repeating thefe fixteen fignals, which were fo diftinft, and 

 fo marked, as diff^erent the one from the other, that they 

 were eafily remembered. The conftruftion of the machinery 

 within the houfe was fuch, that each fignal was uniformly 

 given in precifely the fame manner at all times. It did not 

 depend on the operators' manual fliill, becaufe the pofition 

 of the arms could never for any one fignal be a degree higher 

 or a degree lower than was intended, their movements being- 

 regulated mechanically. M. Chappe, having received at the 

 Louvre the fentence to be conveyed, gave a known fignal to 

 the fecond ftation, which was Montmartre, to prepai-e : at 

 each ftation the obfervers with telefcopcs were on watch, and 

 each telegraph immediately gave the fignal of preparation 

 which he had received ; and this being communicated fuccef- 

 fively through all the line, all the machines were brought 

 into a ftate of readinefs. The perfons at Montmartre then 

 received, letter by letter, the fente/ice from the Louvre, 

 which they repeated with their own machine, and this was 

 again repeated from the next height, with inconceivable ra- 

 pidity, to the final ftation at Line, where the obfervations 

 were written down, and tranflated according to the key 

 which had been before arranged to be ufed, either by pre- 

 vious concert, or by fome particular ^ignal made with the 

 telegraph, to denote that ksy which was ufed. The time 



taken 



