The telephone is an instrument designed to reproduce sounds at a distance by means of electricity. It was believed by most people, and even by eminent electricians, that the speaking-telephone had never been dreamed of by any one before Professor Graham Bell introduced his marvellous little apparatus to the scientific world. But that was a mistake. More than one person had thought of such a thing, Bourselle among the number. Philip Reis, a German electrician, had even constructed an electric telephone in 1864, which transmitted words with some degree of perfection; and the assistant of Reis asserts that it was designed to carry music as well as words. Professor Bell, in devising his telephone, copied the human ear with its vibrating drum. The first iron plate he used as a vibrator was a little piece of clock-spring glued to a parchment diaphragm, and on saying to the spring on the telephone at one end of the line: 'Do you understand what I say?' the answer from his assistant at the other end came back immediately: 'Yes; I understand you perfectly.' The sounds were feeble, and he had to hold his ear close to the little piece of iron on the parchment, but they were distinct; and though Reis had transmitted certain single words some ten years before, Bell was the first to make a piece of matter utter sentences. Reis gave the electric wire a tongue so that it could mumble like an infant; but Bell taught it to speak. The next step is attributed to Mr Elisha Gray of Chicago, who sent successions of electrical current of varying strength as well as of varying frequency into the circuit, and thus enabled the relative loudness as well as the pitch of sounds to be transmitted; and who afterwards took the important step of using the variations of a steady current. These variations, positive and negative, are capable of representing all the back-and-fore variations of position of a particle of air, however irregular these may be: and he secured them by making the sound-waves set a diaphragm in vibration. This diaphragm carried a metallic point which dipped in dilute sulphuric acid; the deeper it dipped the less was the resistance to a current passing through the acid, and _vice versâ_: so that every variation in the position of the diaphragm produced a corresponding variation in the intensity of the current: and the varying current acted upon a distant electro-magnet, which accordingly fluctuated in strength, and in its attraction for a piece of soft iron suspended on a flexible diaphragm: this piece of soft iron accordingly oscillated, pulling the flexible diaphragm with it; and the variations of pressure in the air acted upon by the diaphragm produced waves, reproducing the characteristics of the original sound-waves, and perceived by the ear as reproducing the original sound or voice. Mr Gray lodged a _caveat_ for this contrivance in the United States Patent Office on 14th February 1876; but on the same day