PROCEEDINGS OF THE POLYTECHNIC ASSOCIATION. 555 



not be done with such a contrivance. When the patent for it expires, the 

 Morse telegraph will doubtless be used in England. 



Prof. Henry, of Washington, made in 1829 the essential improvement in 

 producing magnetic power, on which telegraphing depends. The largest 

 electro-magnet made by him sustained a weight of nearly two tons. To 

 excite this power it was not necessary that the battery should be near the 

 magnet. The application of the power by Prof. Morse consisted in making 

 the electro-magnet move a lever. It is evident that motion in only one di- 

 rection could be made by it. This was used to bring the lever down so as 

 to make a dot, by means of a pen at its end. If this pen continued to press 

 while the substance it pressed was moving in one continuous direction, it 

 is evident that a line would be made on the substance instead of a dot. To 

 effect this, a wheel was set to rotating directly under the pen; over this a 

 continuous strip of paper was passed, and thus was furnished the means of 

 making both a dot and a line. When the pen was raised no mark was 

 made. The elements thus obtained were a dot, line and space. An alpha, 

 bet was constructed, each letter being expressed by one or more dots and 

 lines — the letters most used in speaking being made with the least com- 

 plex characters. The operator who wishes to communicate presses a key 

 with one finger, connecting the wires so that an electric force is instantly 

 sent to the opposite end of the wire, which may be hundreds of miles dis. 

 tant, where the magnet makes a mark upon the paper. If the finger of the 

 operator is instantly raised, the key is also raised by a spring, and the cur- 

 rent broken, consequently only a dot is made; but if tlie operator holds 

 down the key for a brief space of time, a line is made instead. The com- 

 munication is thus actually written upon paper, and there can be no mis. 

 understanding it, if properly sent. Such communications have often been 

 produced in courts- of justice as evidence. Expert operators understand a 

 telegram by the sound made by the lever at each time the current passes, 

 A tick corresponds to a dot and silence to a long line. This knack greatly 

 expedites business. For many years attacks have been made upon the 

 claims of Morse to originality; these have grown out of attempts to infringe 

 on his rights. The highest legal tribunal in the land has long since con- 

 firmed the validity of his patent. Prof Morse commenced his experiments 

 in 1832, and in 1836 he exhibited before the students of the N. Y. Univer- 

 sity his magnetic telegraph, embracing the essential characteristics of that 

 now in use. It is the most simple, complete, and useful invention ever 

 made. This practical application of a law of science by new combinations 

 of mechanism, enabling persons separated from each other by hundreds of 

 miles, to hold immediate and direct communication, has done more than so- 

 cial laws to bring people into nearer relations, and bind them in closer 

 communion. The history of the telegraph illustrates the great truth which 

 mere literary men fail to realize, that inventions are the prime movers in 

 the melioration of mankind. • 



It was reserved for another ingenious American to devise such modifica- 

 tions in the telegraphic system, that a communication could be made in 

 print, thus superceding the necessity of copying it, or rather of rendering 

 it into our ordinary alphabetical symbols. The printing telegraph of House . 

 in its mechanical arrangements is more complicated and therefore more 



