''It has long been known that certain flintstones emit a musical note when struck with other flints; and M. Baudre, a French musician, has constructed a piano on this principle. The flints are chosen according to their pitch when struck, and suspended horizontally by their two ends in a row like the keys of a Piano. An elegant metal framework supports the stones, and wires are used to suspend them. A sounding-board is placed a fraction of an inch below the row of stones. Tunes are played by means of two smaller flints held in the hands. The stone which emits the greatest tone weighs 4 lbs.; that which gives the corresponding half-tone weighs 9lbs. This large flint is immediately followed by one weighing 1oz. A 3oz. stone in the set gives the same as another weighing 6,000 grains; so that it is not alone the size of the stones, but other properties which affect the sounds."