If we pass from the method of graphically representing undulations by curves, and proceed to compare the language in which Reis described the action of his machine in reproducing the undulations imparted to the transmitter, with that in which Graham Bell described the action of his machine some fourteen years later, we shall find[53] an agreement even more precise. _Reis._ The =electromagnet= ... will be demagnetised and magnetised correspondingly with the condensations and rarefactions of the mass of air, ... and =the armature ... will be set into vibrations= similar to those of the =membrane= in the transmitting apparatus.--(Legat’s Report, Zeitschrift, p. 128, 1862.) [p. 77.] _Bell._ The current traversing the coils of the =electromagnet E=, occasions an increase and diminution in its intensity, and =the armature A^1 is thrown into vibrations= ... and thus imparts to the air at _n^1_ a =facsimile= copy of the motion of the air that acted upon the =membrane= _n_.--(Specification of British Patent, No. 4765, Dec. 9th, 1876, p. 17.) _Reis._ The transmitter, Fig. A, consists of a =conical tube= ... closed by a =membrane= ... by speaking ... into the tube ... there will be evoked a motion of the =membrane= ... (_op. cit._) _Bell._ A =cone A= is used to converge sound vibrations upon the =membrane=. When a sound is uttered in the cone the =membrane= _a_ is set in vibration.... _Reis._ The apparatus ... offers the possibility of =creating these vibrations= in every fashion that may be desired, and the employment of electro-galvanism gives us the possibility of calling into life, at any given distance, =vibrations similar to the vibrations= that have been produced, and in this way to reproduce at any place the tones that have been originated at another place.--(Legat’s Report, _op. cit._) _Bell._ ... and thus electrical =undulations are created= upon the circuit E _b_ _e_ _f_ _g_.... The undulatory current passing through the electromagnet _f_ influences its armature _h_ to copy the motion of the armature _c_.... These =undulations are similar in form to the air undulations caused by the sound=. _Reis._ As soon therefore as it shall be possible ... to set up vibrations whose =curves are like= those of any given tone or combination of tones, we shall receive the same impression as that tone or combination of tones would have produced upon us.--(Memoir ‘On Telephony,’ p. 60.) [p. 55.] _Bell._ --that is, they are represented graphically by =similar curves=....