Harmonica, Or Armonica a musical instrument, in which the tone is produced by the vibration of bell-shaped glasses, caused by friction from the moistened finger. It was first contrived by Mr. Packeridge, an Irish gentleman, was improved by Mr. E. Delaval, a member of the royal society, and still further by Dr. Franklin, whose instrument had a compass of three octaves from G to g. The glasses, carefully tuned in semitones, were revolved by a pedal movement and touched by the tips of the fingers, occasionally moistened with water. Once tuned, it did not vary from the pitch, and the volume of tone was swelled or diminished by a greater or less pressure. The quality of the tone is exceedingly pure and sweet, but of such a penetrating character that it is painful to the ears of many sensitive persons. A somewhat similar application of glass vessels for musical instruments is described in the Ma-thematische und philosophische Erquickung-stunden, published at Nuremberg in 1677; and a harpsichord harmonica, in which a key action was substituted for finger pressure, was made by Rollig at Vienna, and by Klein at Presburg. In one made by Abbate Mazzuchi, the friction was produced by a hair bow; and Stein, the celebrated organ builder, invented a stringed harmonica, in which strings were used instead of glasses, with a kind of spinet attachment, the effect of which was thought remarkable.

Still another modification was the substitution of steel pegs for the glasses. The construction of Franklin's harmonica is fully described by him in his letters. His enthusiasm evidently expected for the harmonica an extended use, which none of the forms of the instrument have ever attained; nor has it been regarded by musicians or composers as entitled to any higher rank than that of a musical curiosity or toy.