388 MEMORIAL OF JOSEPH HENRY. 



on the success of the telegraph ; and he frankly responded to Henry's 

 inquiry in the following letter : 



"Washixgtox, D. C, April 7, 1856. 



"Sir: In reply to your note of the 3d instant, respecting the 

 Morse telegraph, asking me to state definitely the condition of the 

 invention when I first saw the a])paratus in the winter of 1836, I 

 answer: This apparatus was JNIorse's original instrument, usually 

 known as the type apparatus, in which the types, set up in a com- 

 posing stick, were run through a circuit breaker, and in which the 

 battery was the cylinder battery, with a single pair of plates. This 

 arrangement also had another peculiarity, namely, it Mas the electro- 

 magnet used by ]\Ioll,* and shown in drawings of the older works on 

 that subject, having only a few turns of wire in the coil which sur- 

 rounded the poles or arms of the magnet. The sparceness of the wires 

 in the magnet coils and the use of the single cup battery were to me, 

 on the first look at the instrument, obvious marks of defect, and I 

 accordingly suggested to the Professor, without giving my reasons for 

 so doing, that a battery of many pairs should be substituted for that 

 of a single pair, and that the coil on each arm of the magnet should 

 be increased to many hundred turns each ; which experiment, if I 

 remember aright, was made on the same day with a battery and 

 wire on hand, furnished I believe by myself, and it was found that 

 while the original arrangement would only send the electric current 

 through a few feet of wire, say 15 to 40, the modified arrangement 

 would send it through as many hundred. Although I gave no 

 reasons at the time to Professor ISIorse for the suggestions I had 

 proposed in modifying the arrangement of the machine, I did so 

 afterwards, and referred in my explanations to the paper of Pro- 

 fessor Henry, in the 19th volume of the American Journal of Sci- 

 ence, page 400 and onward. 



"At the time I gave the suggestions above named. Professor 

 Morse was not fiimiliar with the then existing state of the science 

 of electro-magnetism. Had he been so, or had he read and apjire- 

 ciated the ])aper of Henry, the suggestions made by me would 

 naturally have occurred to his mind as they did to my own. But 

 the principal part of Morse's great invention lay in the mechanical 

 adaptation of a power to produce motion, and to increase or relax 

 at will. It was only necessary for him to know that such a power 

 existed for him to adapt mechanism to direct and control it. ISIy 

 suggestions were made to Professor Morse from inferences drawn by 

 reading Professor Henry's paper above alluded to. Professor Morse 



*[More correctly, the magnet of Sturgeon.] 



