TQg DESCRIPTION OE A TELEGRAPH USED IN SWEDEN. 



fpecVive line by means of united firings, thus to reprefent I 

 a firing attached to that.fhutter is faflened to a rod numbered 

 1 ; for 2, a llring is brought from that fhutter to a rod num- 

 bered 2; but to produce 3, a firing from each of the fhutters 

 1 and 2 is affixed to the rod numbered 3, and in a fimilar 

 manner 5, 6 and 7, are each produced by combining the firings 

 before they are united to the rods. In this method the num- 

 ber of the rods are increafed to 22, but as only one of each 

 line can be ufed at once, and they are all numbered, there is 

 lefs probability of a miflake, and the quicknefs of the opera- 

 tion is increafed. 

 Requires only According to the conflruction above defcribed, it will be 

 one or ^per- f een ^^ one p er f on j s f u ffi c i eri t to work the largeft telegraph 

 at the extremities of the line of flations, provided the telefcope 

 is fo placed that he can look-out and work the (nutters at the 

 fame time ; but in the intermediate flations, where the obferva- 

 tions mull be made with two telefcopes, in contrary directions, 

 who need not there Ihould always be two perfons who may relieve each other, 

 be men of j t j s not re q U ifi ie that they mould be men above the common 



rank ; all that is wanted of them is to be able to write down 

 the numbers, and to combine 1,2, 3, 4. In the attempts 

 Children made by the Chevalier, he, during a year and half, employed 



employed. on \y children, and a very few hours were fufficient to give 



them a complete knowledge of what was required of them. It 

 was for this reafon he was induced to facrifice ibmething of the 

 limplicity of the mechanifm to fimplicity in the execution. 

 When thofe employed are not well fkilled in the ufe of the 

 machine, it is important not to load their memory or their con- 

 ception with too many details, and it is probably to this as 

 much as to rapidity of execution that the chief merit of this 

 telegraph is owing. 

 Theobfervatory. The obfervatory fhould always be placed below the tele- 

 graph, and fhould enclofe the telefcopes and machinery with 

 which the telegraph is worked. It ought to be as much dark- 

 ened as poffible, and painted black withinfide, in order that 

 all foreign light may be excluded, by which means the impref- 

 fion of an object is rendered much more diflincl to the eye. 



Methods of vfing the Telegraph by Night. 



Methods of For the purpofe of rendering the telegraph ufeful in the 



ufmg the tele- night, the following plans are adopted. 



graph by night. r 



