A musical instrument, of the class called " Free-reed " instruments, in which the sound is produced by the vibrations of thin tongues or slips of metal. The invention is very recent, of German origin, and the instruments are, for the most part, manufactured in Germany. They are variously constructed, with a greater or less number of reeds and keys, thereby producing a greater or less range of notes; but the most common form is similar to that shown in the accompanying engravings: of which Fig. 1 affords a front view, Fig. 2 a plan exhibiting the arrangement of the system of reeds, and Fig. 3 a vertical section of Fig. 1. Fig. 4 shows a plan of a single pair of reeds, of the full size, and Fig. 5 a vertical section of the same, a a represents a rectangular box, the lower portion of which, b, is composed of an air-tight flexible material, forming the bellows and wind chest; c is a horizontal partition of wood forming the top side of the wind chest, on the upper surface of which are formed one large cell d, and ten smaller cells ee.
In the bottom of each cell there are two apertures cut through the partition c; each of these apertures is covered on one side by a thin metallic plate f, having an oblong piece cut out of the middle of it; and this oblong hole is imperfectly stopped by an elastic tongue g (made of thin brass), rivetted at one end to the metallic plate /, as shown in the figures 4 and 5. The tongue g is thus made (by the current of air driven through the aperture) to vibrate freely in the oblong space cut out of the plate f, and is technically termed a "Free-Reed."
On the other side of each aperture there is cemented at one edge a flap or valve of thin leather. The reeds in each cell are fixed one to the upper side of the partition, and one to the lower side, as shown in the figures 4 and 5, so that notes are produced both by the expansion and the contraction of the wind-chest. The larger cell d likewise contains two plates f, with valves h adapted to each as in the smaller cells; but the plates in this large cell contain each three reeds, so toned as to form chords with the other notes. The partitions of the cells are faced on the upper side with buff leather, over which the cover i i slides, and forms therewith an air-tight joint. In the cover over each of the small cells is a hole closed by a key k, and over the larger cell are two holes, one at each end, closed by the keys 11, which are moved simultaneously by the knob m. The notes are produced either by the distension or by the compression of the bellows, according to the note required; and two or more notes can be sounded at once as on the piano or organ.
There is a valve or key n, in the bottom of the wind-chest, by the opening of which the action of the air upon the reeds is prevented, and the bellows may be extended or contracted without producing any sound; so that when a succession of ascending or descending notes are required, each occupying the whole range of the bellows, the wind-chest can be filled or discharged during the return stroke between each note, without producing any sound. The keys 11 are generally kept open, thereby producing chords; but they may be closed, in which case the air alone is played. The instrument is extremely portable, and when well made, the sounds are but little inferior to those of an organ. There are numerous other instruments made on the same principle, as the Concertina, Seraphine, Aelophon, etc.