305 



printiug process. One set of the different suspended magnets are so 

 adjusted, that a current in one direction of any strength falling short 

 of a certain limit makes only one of them move ; that a current in 

 the same direction, of strength exceeding this limit but falling short 

 of another limit, moves another also of the suspended magnets ; and 

 so on for a succession of different limits of strength of current in one 

 direction. The remaining set of suspended magnets are adjusted to 

 move with different strengths of current in the other direction 

 through the coil. Without experience it is impossible to say how 

 many gradations of strength could be conveniently arranged to be 

 thus distinguished unmistakeably. I have no doubt, however, that 

 very moderate applications of electric resources would give at least 

 three different strengths of current in each direction, which could 

 with ease and certainty be distinguished from one another by the test 

 which the suspended magnets afford. Thus, a signal of six varieties 

 one letter of an alphabet of six could be recorded by almost in- 

 stantaneous movements of six suspended magnets, making one, two 

 or three marks by one set of three styles, or one, two or three marks 

 by another set of three styles, placed all six beside one another, 

 pressing on a slip of electro-chemical paper drawn by clockwork, as 

 in the Morse instrument. 



In subterranean or submarine lines of less than 100 miles length, 

 it would be easy, by means of simple battery applications, followed by 

 connexions with the earth, or by means of simple electro-magnetic 

 impulses at one end of the wire, to give ten or twelve of such signals 

 per second without any confusion of utterance at the other end. The 

 confusion of utterance which would be experienced in working thus 

 through longer lines would be easily done away with, in any length 

 up to 500 miles, by following up each battery application with a 

 reverse application for a shorter time, or by following up each electro- 

 magnetic impulse by a weaker reverse impulse, so as approximately 

 to fulfil the condition (described in my former communication), of re- 

 ducing the subsidence of the electrification in the wire to the double 

 harmonic form. It would, I believe, be readily practicable to send 

 distinctly five or six such signals per second (each a distinct letter of 

 an alphabet of six) through a wire of 500 miles length in a submarine 

 cable of ordinary dimensions. To perform the electrical operations 

 required for sending a message on this system, mechanism might be 



