IN a work of this nature it would be absolutely impossible, not to say out of place, to give an account of so elaborate a subject as Acoustics, i.e. the science of Sound. Suffice it to say, that all sounds are produced by the vibration of air, and that the fewer vibrations, the lower is the sound, and vice versâ.

When such vibrations are produced regularly, they form Musical sounds, but, if irregularly, the sounds can be only distinguished under the term of Noise. The earliest germ of music lies in certain savage races, who, as long as they can maintain a rhythmical beat on any resonant substance, do not particularly care what it is. A hollow tree is a splendid instrument in their opinion, but, if this cannot be had, a dry log of wood will answer the same purpose.

Some tribes, more ingenious than others, cut a deep groove upon the upper surface of a log, hollow it through this groove, and then hammer away at it to their hearts' content. The next move was to cut off a section of the trunk of a tree, hollow it, set it on end, and then beat it on the sides.

Lastly, some one hit upon the idea that if the open upper part of the hollowed log were covered with a tightly stretched membrane, and that if the membrane, instead of the log, were beaten, the resonance would be increased.