TELEGRAPH. 



taken up for each movement was about twenty feconds ; of 

 whicli the motion alone took up four feconds ; and during tlie 

 other fixteen, the telegraph was kept ftationary, that it might 

 be diftinClly oblerved and written down by the people at 

 the next ftation. The figns were fometimes made for words, 

 and fometimes for letters: when in words, a fmall flag was 

 hoilled ; and as the alphabet could be changed at plcafure, it 

 was only the correfponding perfons at each end of the line 

 wlio knew the meaning of the figns. In general, news was 

 gi\-en every day about eleven or twelve o'clock ; but the 

 obfervers were conftantly on the watch, and as foon as a cer- 

 tain fignal was given and anfwered, they begun from one 

 end to the other to move their machines. All the moveable 

 paits wefe painted of a dark-brown colour, to be more dif- 

 tinftly vifible when viewed againft the bright &y. 



Another line of telegraphs, from Paris to Landau, was 

 completed in 1796: the firll of them was erefted on a 

 pavihon of the palace of the Tuilleries. The conftruftion 

 was more comphcated than the firil. A fixed black bar, 

 fifty feet long, was fupported horizontally by four uprights. 

 This bar carried five indicators, fimilar to the fmaller indi- 

 cators of the machines before defcribed. Two of the up- 

 right pofts which fupported the horizontal bar, carried each 

 a fimilar indicator : in this way the centres of the indicators 

 were all ftationary, inftead of having the long indicator with 

 fmaller ones at the extremities. Thefe feven indicators were 

 moved by puUies, in the ufual way ; and there was none of the 

 difficulty of conveying the communicating cords through the 

 hollow axis of the central pulley. Each of the indicators 

 could take feven diftinft pofitions ; -uiz. for thofe which 

 were fupported by the horizontal bar,- two vertical, four 

 inclined, and one horizontal ; and for thofe indicators which 

 were fupported by the upright pofts, one vertical pofition, 

 four inclined, and two horizontal ones. The number of 

 combinations which fuch a conftruftion can make, is 

 7x7x7x7x7x7x7, which gives the ailonifhing 

 number of 823,543 fignals. This number, which is eight 

 thoufand times larger than that of the fignals of the firft 

 telegraph, is doubtlefs more than fufficient : it, however, 

 allowed them to abridge confiderably the telegraphic lan- 

 guage, and to tranfmit whole phrafes at a time. 



The Engl'tjli Telegraph. — M. Chappe's machine was known in 

 England not long after it was fet up, and two working models 

 were made at Frankfort, and fent to England, by which the 

 plan and alphabet became known ; and its advantages were fo 

 obvious, that the Britilh government tried various experiments 

 on telegraphic communication, and at length lines were efta- 

 bli(3ied from the Admiralty -ofiice to Deal, Portfmouth, and 

 other points of the fea-coaft. Thefe machines are upon the 

 conftruftion reprefentcd v\ fig- 3, not being made with indi- 

 cators, like the French, to move upon centres into different 

 pofitio;is, but with fix oftagon boards, each poifed upon an 

 horizontal axis, and fupported in a frame in fuch a manner, 

 that each can be placed vertically, and will then appear of 

 the full fize ; or if they are placed edgeways, as fliewn at d, 

 the naiTOw edge alone will be prefented, and this at a fmall 

 diftance will be invifible. The boards are turned by means 

 of cranks, r, upon the end of the axles, and from thefe, lines 

 defcend into the cabin below, where each has a handle, which 

 is confpicuoufly marked with the letter or charadler which 

 will be indicated when the handle is drawn down. 



By the changes in the pofition of thefe fix boards, thirty- 

 fix changes may be eafily exhibited, and the fignal to repre- 

 fent any letter may be made. By certain pofitions, a variety 

 of other things may be fignified, according to the will of 

 the two perfons employed at the two extreme pofts in 

 jiiaking the fignals. Thus, one board being in a horizontal 



Vol. XXXV. 



pofition, and the others fhut, or in a perpendicular fituation,- 

 may denote the letter a ; two boards only being in a hori- 

 zontal pofition may give tiie letter h ; ilirec in the fame 

 manner, llie letter c, and fo on. As theve may be made as 

 many changes with thefe boards as with the fame number 

 of bells, the letters of the alphabet may be made with eafr, 

 and a fufficient number of fignals may be formed for extra- 

 dinary purpofes. 



This number of changes is fufficient ; for as this telegrapli 

 is intended to convey information by reprefenting the fuc- 

 cefTive letters of each word, a greater number of changes, 

 than would cxprefs all the effential letters of the alphabet," 

 the numerals, and three or four more lignals, to fignify at- 

 tention, repeat, period, error, &c. would be only em- 

 barralfing, and liable to error. It is a good fyftem to fpell 

 every word, rather than attempt to communicate entire word» 

 or fentences, as by keeping always to one fyftem, mif- 

 takes are avoided. The communication is in itfclf fo rapid, 

 that it is more important to attain certainty in the operation, 

 than to make any facrifice for the fake of difpatch. 



This telegraph was judicioufly contrived to have a fufTi- 

 cient number of combinations, without having more tlian 

 necefTary. Five boards would have been infiifhcient, and 

 feven more than were necefTary. But there are feveral 

 ferious objeftions to it : the form renders it too bulky 

 to admit of being raifed to any great height above a build- 

 ing ; and after all, the boards are lefs evident to the eye 

 at a diftance than the indicators of the French machine. 

 The ftations muft, therefore, be nearer together, to ren- 

 der the bars of the frame vifible as well as the boards. 

 Neither can this telegraph be made to change its diredion, 

 but it can only be feen from one particular point. It was 

 found necefTary to have two telegraphs at the Admuralty, 

 one for each line, and alfo at any point of the line where it 

 branched off. 



To enable the telegraph to be ufed at night, the flrll 

 French telegraph which was fet up was furnilhed with 

 Argand lamps, but the Englifli was never ufed in that man- 

 ner. It would have required a great number of lamps ; 

 becaufe it would have been necefliiry to have fixed lamps to 

 indicate the points of the frame in which the boards work, 

 as well as the boards themfelves. 



Thefe two forms of telegraph, the French and the Eng- 

 lifh, continued in ufe for fome years. The French made 

 frequent changes in the details of their fyftem, though for 

 a long time they preferved M. Chappe's machine ; and when 

 Buonaparte alTumed the fupreme command in France, the 

 original machines were taken down. A number of machines 

 were fet up on various parts of the French coaft, and were ufed 

 in fome of their campaigns : they were of a very temporary 

 nature, and compofed of the fimpleft materials, of marts 

 and yards, with large balls at the end ; the yards were in- 

 clined by cords, fo as to cffetl the fignals on the fame prin- 

 ciple as M. Chappe's original machine. About 1806 a new 

 fe't of telegraphs was cftabhfhcd on the whole extent of 

 the coaft of the French empire, of which the following de- 

 fcription is given by captain C. W. Pafley, in the Philo- 

 fophical Magazine. Sce^^j. 5 and 6, 



Modern French Telegraph. — Every telegraph confifts of 

 an upright poll, R, to which are attached three arms, 

 A, B, and C, exaftly fimilar to each other, and each mov- 

 ing upon its own diftinft fpindle or axis. The axis of one 

 of thefe arms. A, is near the head of tlie poft R ; and the dif- 

 tance between the centres of motion of either of ihc two 

 uppermoft arms, and the centre of the one immediately be- 

 low it, is rather lefs than double the length of one arm. 

 The higheft of the thiec arms, A, can e.'thibit ftvcn dif- 

 E e tinft 



