consequence of this the Great Eastern had to return without having completed the task. A new company, the Anglo-American Telegraph Company, was formed in 1866, and at once entrusted Messrs. Glass, Elliott and Company with the construction of a new cable of 3,000 kilometres. Different arrangements were made for the outer envelope of the cable, and the Great Eastern was once more equipped to give effect to the experiments which had just been made. The new expedition was not only to lay a new cable, but also to take up the end of the old one, and join it to a new piece, and thus obtain a second telegraph line. The sinking again commenced in Ireland on the 13th of July, 1866, and it was finished on the 27th. On the 4th of August, 1866, the Trans-Atlantic Telegraph Line was declared open." _A. R. von Urbanitzky, Electricity in the Service of Man, pages 767-768._ ELECTRICITY: A. D. 1876-1892. The Telephone. "The first and simplest of all magnetic telephones is the Bell Telephone." In "the first form of this instrument, constructed by Professor Graham Bell, in 1876 ... a harp of steel rods was attached to the poles of a permanent magnet. ... When we sing into a piano, certain of the strings of the instrument are set in vibration sympathetically by the action of the voice with different degrees of amplitude, and a sound, which is an approximation to the vowel uttered, is produced from the piano. Theory shows that, had the piano a much larger number of strings to the octave, the vowel sounds would be perfectly reproduced. It was upon this principle that Bell constructed his first telephone. The expense of constructing such an apparatus, however, deterred Bell from making the attempt, and he sought to simplify the apparatus before proceeding further in this direction. After many experiments with more, or less unsatisfactory results, he constructed the instrument ... which he exhibited at Philadelphia in 1876. In this apparatus, the transmitter was formed by an electro-magnet, through which a current flowed, and a membrane, made of gold-beater's skin, on which was placed as a sort of armature, a piece of soft iron, which thus vibrated in front of the electro-magnet when the membrane was thrown into sonorous vibration. {777} ... It is quite clear that when we speak into a Bell transmitter only a small fraction of the energy of the sonorous vibrations of the voice can be converted into electric currents, and that these currents must be extremely weak. Edison applied himself to discover some means by which he could increase the strength of these currents. Elisha Gray had proposed to use the variation of resistance of a fine platinum wire attached to a diaphragm dipping into water, and hoped that the variation of extent of surface in contact would