DESCRIPTION OF A TELEGRAPH USED IN SWEDEN; 195 



VIII. 



Defcription of a Telegraph ufed in Siveden. Conftrucled by Sir 

 A. N. Edelcrantz, CounfeUor of the Chancery, and pri- 

 vate Secretary to the King of Siveden, Archivift of the Orders 

 of His Majejiy, and One of the Eighteen Members of tht 

 Swedifh Academy. From the Copy of a Treatife on Telegraphs, 

 communicated by the Author. 



x\FTER numerous obfervations on the various defcriptions Qualities requl- 



of fignals, and an hiftorical detail of the ufe of them, from the flte !" a te,c " 



. graph j 



raoft remote antiquity to the prefent time, the author ftates 



the principal qualities of a good telegraph to confift in : 



1. Perfection in the principle of the machine, and in the 

 nature of the fignals. 



2. Perfection in the means employed to work the machine; 

 The firft of thefe requires : 1. a fufficient number of fignals 



to exprefs not only letters, but alfo fuch words and phrafes as 

 are in general ufe : 2. that the fignals (hall be fo apparent; 

 that any one may fee them very dillinclly : 3. that the appli- 

 cation of the fignals to their refpeclive fignifications (hall be 

 «afily underftood and retained « 



The fecond requires : 1 . the leaft poffible weight and fric- 

 tion of the parts : 2. quicknefs in the movements and changes 

 of the fignals : 3. certainty to prevent miftakes and ambiguous 

 remits. 



The credit of uniting all thefe qualities in one machine, are firft united by 

 afcribed to M. Chappe, the inventor of the French telegraph, M * Cha PP e « • 

 of which he gives a defcription. The number of fignals it is 

 capable of, allowing the angle of inclination of its refpective 

 arms to be 45°, is 256 ; by diminifliing that angle to 30° they 

 may be increafed to 864, and in like manner the number may 

 be ftill further augmented by every diminution of the angle, 

 but the fignals would be proportionally lefs diftincl. 



When this difcovery was announced, the learned of all coun- Attempts to 

 tries inftituted enquiries into its principles and conftru&ion. difcoverthecon* 

 Among others, the Chevalier made various machines, fome p r ; nc j p]es f ^ 

 refembling the French telegraph, and others totally different, French tele. 

 and after many attempts he fucceeded in conftru&ing that grap 

 which is the principal fubjeft of his treatife, and to which he 



Vol. V. — July. O gave 



