[9] Proc. Soc. Telegr. Engin. and Electr. vol. xi. p. 134, 1882. [10] ‘Electrical Review,’ July 22, 1882, p. 49. [11] Mr. E. Albert, of the firm of J. W. Albert and Sohn, of Frankfurt, to whom Reis entrusted the manufacture of Telephones for public sale, thus writes: “The most important part was the membrane, because the delicacy of the apparatus depended principally upon that part. As it was not possible to make every membrane equally good, so it came about that instruments of different degrees of superiority came into use, and various decisions were arrived at as to the ability of the instrument to perform the functions for which it was designed. Those who happened to have a poor instrument were able to hear but little; while those who possessed a good instrument were astonished at its performances. A good instrument reproduced the words sung into it in such a manner that not only the pitch but also the words of the song were perfectly understood, even when the listener was unacquainted with the song and the words.” M. St. Edmé, of Paris, who contributed to ‘Cosmos,’ vol. xxiv. p. 349, 1864, an article on Reis’s Telephone, of which he had seen an example in König’s _atelier_, said that when the scale was sung it needed a trained ear to distinguish the notes amidst the noises of the receiver. He must have got hold of an uncommonly bad transmitter with a flabby tympanum to have failed so completely. [12] Letter of Dr. Messel to Professor W. F. Barrett quoted, in Professor Barrett’s memoir, ‘On the Electric Telephone,’ read Nov. 19, 1877, to the Dublin Royal Society. Vide Proc. Roy. Soc. Dubl. 1877. [13] See Barrett’s ‘Telephones Old and New’ (1878), p. 12. [14] See Reis’s own remark at bottom of p. 57. CHAPTER IV. CONTEMPORARY DOCUMENTS. The following documents, drawn from the scientific literature of the time, are placed in chronological order, beginning with the first memoir published by Philipp Reis himself, in the _Jahresbericht_ of the Physical Society of Frankfort, for the year 1860-61. Every care has been taken that the translations here given shall be faithful in every detail to the originals. All notes and comments by the translator are distinguished by being enclosed in square brackets. [=1.=] ON TELEPHONY BY THE GALVANIC CURRENT. _By_ PHILIPP REIS. [Translated from the Annual Report (Jahresbericht) of the Physical Society of Frankfurt-am-Main, for 1860-1861.] The surprising results in the domain of Telegraphy, have often already suggested the question whether it may not also be possible to communicate the very tones of speech direct to a distance. Researches aiming in this direction have not, however, up to the present time, been able to show any tolerably satisfactory result, because the vibrations of the media through which sound is conducted, soon fall off so greatly in their intensity that they are no longer perceptible to our senses.