We adventure into the study of sound and its laws and we find that all sounds are propagated by means of waves. These proceed in circular fashion, as do the ripples upon the still surface of a lake into which a stone has been thrown. Further, these waves are of differing rates. Middle C, on the piano, for instance, is made by waves that reach us at the rate of about 256 per second. As sound travels roughly at 1,100 feet to the second, it is clear that the wave of this note is something over four feet from crest to crest. The wave of a note an octave higher would be double the rate and half the length. In addition to this there may be big waves and little waves travelling at the same rate, and also the actual shape of the waves may differ very widely. Thus waves have points of similarity and yet their infinite variety, as do human beings. This variety in the shape of the waves results in the difference in timbre between various tones. Nobody could fail to distinguish between the sound of a note played on a penny whistle and the same note given out on a violin or a cornet: yet the actual rate of wave would be the same in each case. The reason is that no tone is a pure fundamental tone, there are always super-added a number of other tones, termed the overtones. These are, to the original tone, exactly what the flavouring is to the pudding. You have your fundamental tone and you can add your overtones to taste: you can flavour with the penny whistle, the violin, or the cornet timbre to suit yourself. But according to the flavouring, so is the shape of the wave. Isolated fundamental tones are apt to be colourless and monotonous, like the diapason work on an organ. The organist is able to flavour his fundamental tone at will, by the stops he draws to add to it: he has a special supply of "mixtures" which sound truly dreadful and impossible by themselves, but these in combination with the fundamental go to the making of a successful timbre. Carrots, by themselves, are not a Christmas diet, but we understand that they go to improve the flavour of the festive pudding.