DESCRIPTION OF A TELEGRAPH USED IN SWEDEN. \Qj 



of l t to the fecond 2, and to the laft 4, and from the value 

 of the tingle (nutters form that of their combinations. Thus 

 when the firft and fecond mutters on a line are vifible, they 

 will fignify 3 = 1 + 2, the firft and third 5 = 1 + 4, the 

 fecond and third 6 = 2 + 4, and the three together 7 = 

 1 +2 + 4, and in the fame manner for each vertical line. 

 If in any of the lines no fhutter is vifible, the vacancy is ex- 

 prefTed by o. Thefe three lines give 5 1 2 different fignals, 

 and the number is doubled by the addition of the fhutter A. 

 Thus in expreffing the number of the fignal, fuppofe the firft 

 and fecond fhutters of the firft line to be feen, all three on the 

 fecond line, and none on the third, the value muft be written 

 370, if to thefe the fhutter A is added, the number muft be 

 exprefTed by A 370, and fo of every other combination. On 

 the left fide of the machine is placed an arm H, the ufe of 

 which is partly to direct the arrangement of the lines, begin- 

 ning from that fide ; and partly to point out the middle fhutter 

 in each line. It may be made moveable on hinges, and can 

 then be concealed or made vifible at pleafure. It will be 

 eafily conceived that the method of valuing the lines may be 

 varied by agreement, fo as to be reckoned from right to left, 

 or horizontally, in either direction : thus the pofition of the 

 telegraph as indicated above, may be exprefTed by 370 — 

 670 - 073 - 076 - 662 - 266 - 332 or 233, but the me- 

 thod firft defcribed feems to be the moft natural. 



By the mode of reckoning, the value of the fhutters as de- 

 fcribed above, it will be feen that they are capable of expref- 

 fing every number of three places, from 000 to 777, which 

 does not contain an eight or nine. To make ufe of thefe num- 

 bers, a table muft be conftructed on the following plan. 



O 2 



