PROCEEDINGS 



OF THE 



AMERICAN ACADEMY 



OF 



ARTS AND SCIENCES. 



VOL. XII. 

 PAPERS READ BEFORE THE ACADEMY. 



I. 



RESEARCHES IN TELEPHONY. 

 By A. Graham Bell. 



Presented May 10, 1876, by the Corresponding Secretary. 



1. It has long been known that an electro-magnet gives forth a 

 decided sound when it is suddenly magnetized or demagnetized. 

 "When the circuit upon which it is placed is rapidly made and broken, 

 a succession of explosive noises proceeds from the magnet. These' 

 sounds produce upon the ear the effect of a musical note, when the 

 current is interrupted a sufficient number of times per second. The 

 discovery of " Galvanic Music," by Page,* in 1837, led inquirers in dif- 

 ferent parts of the world almost simultaneously to enter into the field of 

 telephonic research ; and the acoustical effects produced by magnetization 

 were carefully studied l)y Marrian,t Beatson,! Gassiot,§ De la Rive,|| 



* C. G. Page. "The Production of Galvanic Music." Sllliman's Journ., 



1837, XXXII., p. .596; Silliman's Journ., July, 1837, p. 854; Silliman's Journ., 



1838, XXXIIL, p. 118; Bibl. Univ. (new series), 1839, XL, p. 398. 



t J. P. Marrlan. Phil. Mag., XXV., p. 382; Inst., 1845, p. 20; Arch, de 

 l']fclectr.,V., p. 105. 



t IF. Bfalson. Arch, de I'Electr., V., p. 197 ; Arch, de Sc. Phys. et Nat. 

 (2d series), II., p. 113. 



§ Gassiot. See " Treatise on Electricity," by De la Rive, I., p. 300. 



II De la Rive. Treatise on Electricity, I., p. 300; Phil. Mag., XXXV., p. 422 ; 

 Arch, de I'Electr., V., p 200; Inst., 184G, p. 83; Coniptes Kendus, XX., 

 p. 1287; Comp. Rend., XXII., p. 432; Pogg. Ann., LXXVI., p. 637; Ann. de 

 Chim. et de Phys., XXVI., p. 158. 



VOL. Xll. (n. S. IV.) 1 



