DESCRIPTION OP A TELEGRAPH USED IN SWEDEN. 197 



knowledge of cryptography. Several plans of this kind are 

 inferted by the Chevalier, the details of which would extend 

 the limits of this paper too far. 



Methods of working the Machine. 



It has been already noticed, that a fmall machine may be Methods of 

 worked by the rings tt, but as the ftrength of the fingers are wor ms * 

 unequal to the weight and refiftance of a large machine, more 

 powerful means muft be had recourfe to. With this view the 

 author propofes to replace the rings with metal rods affixed to 

 the firings, and having a button at the lower extremity of each. 

 To work the machine fo prepared, he propofes to have an in- 

 ftrument of iron nearly in the form of a T, at the bdttom of 

 which (hall be an opening or ftirrup to receive the foot. The 

 crofs arm of it is to have ten notches correfponding to the ends 

 of the rods, and is to be kept on a level with them by a weight 

 behind. When a lignal is to be made, the ends of the rods 

 hanging to the mutters which are to be clofed, are flipped into 

 their refpe&ive notches, and the machine is worked by pref- 

 fkig down the inftrument with the foot. When the lignal has 

 been obferved the foot is withdrawn, and the inftrument re- 

 fiored to its original pofition, by the weight which has been 

 defcribed. The rods are then difengaged, and the whole is 

 in a fiate of preparation for the next lignal. This may be 

 more expeditioufly performed by another contrivance formed 

 of ten plates of metal moveable on a common axis, and each 

 having a hollow in its outer edge. When the machine is at 

 reft, thefe plates are in a vertical pofition, and the box con- 

 taining them is placed before the lower ends of the rods. To 

 make a fignal, the plates correfponding with the rods intended 

 to be acted on, are pufned with the fingers into an horizontal 

 pofition, and the box Hid along in two grooves made for the 

 purpofe, by which means all thofe rods are prefled into their 

 refpeclive notches at once, and a confiderable fpace of time 

 is faved, while the rods whofe correfponding plates retain their 

 vertical pofition are unmoved. If a ftill greater force is re- 

 quired to work the machine than can be obtained by the foot, 

 a winch with rackwork, or with a pulley, inftaad of the up- 

 right bar of the inftrument, may be applied to the crofs arm. 



In order to afford more perfpicuity in making a lignal, the Each fignal may 



Chevalier alfo propofes to form the combinations of each re- be made by 



r ~. drawing one rod 



fpeQro&-fcjrte 



