During the last century, a German professor, named Huth, made a model of the horn, and found it answered every purpose of a speaking-trumpet with most powerful results, but we beg leave to doubt whether the instrument really carried the voice to any very great distance. The Acoustic Cornet, which is the counterpart of the speaking-trumpet, has been made in many different forms during the last two centuries, but none of them to the present time consist of anything more intricate than a simple tube with a mouthpiece and bell-shaped orifice. Professor Edison, however, in his researches regarding the conveyance of sounds, has made numerous and interesting experiments. On one occasion, with his Megaphone he carried on a conversation at a distance of nearly two miles, without any other assistance from instruments except a few little cornets of cardboard. These constitute the Megaphone, which may be regarded as a curiosity, considering the effects produced by such simple means. The illustration (fig. 185) represents the instrument which is (or was lately) fixed upon the balcony of Mr. Edison’s house. At a mile-and-a-half distant from the house, at a spot indicated by the two birds in the picture, another instrument was fixed, and conversation was carried on with ease. Perhaps the present opportunity will be the most convenient to speak of the AUTOPHONE, although it is more a musical than an acoustic instrument. Until lately Barbary organs and piano organs have been the only means by which poor people have been able to hear any music, and that not of a very elevated class. Besides, there is a good deal of expense connected with the possession of an organ. But the Americans, with a view to popularize music, have invented the AUTOPHONE, which is simply a mechanical accordeon, manufactured by the Autophone Company, of Ithaca, New York. The principle of the instrument is represented in fig. 186, and is extremely simple. An upright frame carries within it on one side a bellows, and on the other a flexible air chamber, which serves as a reservoir. The upper portion contains a set of stops like an accordeon, but the escape of the air through the small vibrating plates can only take place by the upper surface of the frame work, upon which slides a thin plate of Bristol board pierced with holes at convenient distances, and set in motion by the mechanism shown in the annexed diagram (fig. 187). [Illustration: Fig. 186.—The Autophone.] The figure represents an axle furnished with a series of “washers,” which, acting upon the plate, cause it to move round. It is the bellows movement that turns the axle by the aid of two “catches,” B and C, which work upon a toothed wheel fixed upon it.