64 APPENDIX. 



" UNITED STATES PATENT OFFICE, j 

 MARCH 31, 1856. J 



"SiR, Agreeably to your request, I now make 

 the following statement : Some two years since, 

 when an application was made for an extension of 

 Professor Morse's patent, I was for some time in 

 doubt as to the propriety of making that exten- 

 sion. Under these circumstances, I consulted 

 with several persons, and among others with 

 yourself, with a view, particularly, to ascertain 

 the amount of invention fairly due to Professor 

 Morse. The result of my inquiries was such as to 

 induce me to grant the extension. I will further 

 say that this was in accordance with your express 

 recommendation, and that I was probably more 

 influenced by this recommendation, and the infor- 

 mation I obtained from you, than by any other 

 circumstance, in coming to that conclusion. 



"I am, sir, 



"Yours very respectfully, 



" CHARLES MASON." 

 "PROF. J. HENRY." 



NOTE X, PAGE 50. 



In reversing the galvanic current on the po- 

 larized relay used by Henry in Albany, and now 

 largely used, the armature is moved both ways by 

 magnetism that is, it strikes the sounder, and is 

 withdrawn from it, by magnetism. When the 

 current is not reversed, but is broken at each 

 signal, magnetism only operates one way, and a 



