The combined effect of A and B, when induced simultaneously on the same circuit, is expressed by the curve A + B, Fig. 4, which is the algebraical sum of the sinusoidal curves A and B. This curve A + B also indicates the actual motion of the air when =two musical notes= considered are sounded =simultaneously=.... (_Ib._) The electrical movement, like the aerial motion, can be represented by a sinusoidal curve, or by the =resultant of several= sinusoidal =curves=.--(_Ib._) The very remarkable agreement of the preceding passages receives a most striking confirmation by comparing the curves respectively drawn by Reis and by Bell. These are facsimiled below, Reis’s “combination”-curve (Fig. 47) from Plate I. of his Memoir (also Plate I. of this volume), and Bell’s “resultant”-curve (Fig. 48) from Fig. 4 of his United States Patent Specification No. 174,465. The most casual observer cannot fail to notice here that the three lines of undulatory curves of Bell’s specification are practically identical with the three lower lines of undulatory curves of Reis’s memoir. They are, moreover, in each case introduced for the sake of showing how a complex curve corresponds to a compound undulation. _Reis._. [Illustration: Fig. 47.] _Bell._. [Illustration: Fig. 48.] Far be it from me even to hint that either curve was plagiarised from the other. Bell tells us that his curve is to represent electrical oscillations, which, he adds, have the same curve as that both of the vibrating body and of the air. Reis tells us that his curve is to represent the oscillations of a tympanum, or of the air, or of the magnetisation of the magnet, or of the armature at the receiving end. How the magnetization of the electro-magnet was made to vary “correspondingly with the condensations and rarefactions of the air,” as represented by such a curve, Reis did not explicitly say, but left to the common sense of his readers to infer. Though the inference was obvious, Bell, who possibly had not then read Reis’s researches, seized upon this intermediate stage of the process employed by Reis, and probably quite unconscious that Reis had already employed it, announced it as a discovery of his own; and then, losing sight of the point that all that was wanted was to secure correspondence between the initial and final stage, he magnified to an absurd and unwarranted importance this intermediate correspondence of the vibrations of the current with those of the tympanum, which correspondence any one reading Reis’s papers would know at once Reis had implicitly assumed and actually employed when he transmitted articulate speech.