tube, the width of the month-piece and its length, the size and thickness of the tongue, the diameter of the instrument, the size of the orifice, the nature of the material of which it is composed, etc., variations in any of which produce—sometimes very important—modulations in its tone. Experiments have shown that do and mi in particular have a round, full, well-supported sound, which in the Baduel regulation whistle can be heard for a distance of more than six hundred metres.
Competent observers have asserted that the manner of whistling is not always the same, and that there are some unhappy persons who can not whistle at all. According to these authorities, among whom is M. Baduel, to whistle well it is necessary to pronounce tu . . . tu slowly; then tu . . . tu . . . tu more and more rapidly and quite distinctly, especially taking care not to whistle from the throat. To make the double tongue-stroke, we must say tu . . . du . . . g, du, to give the trill; but we should always begin slowly, and proceed gradually to greater rapidity.
Correspondents of "La Nature" have sent in to it illustrations and descriptions of other whistles than those which M. Gutode describes. One of them is a terra-cotta bird-shaped whistle, somewhat like the Peruvian whistles, which has been recovered from the prehistoric relics near Florence (Fig. 5). The
Fig. 5.—Earthen Whistle from near Florence.
sound is produced by blowing into the bird's beak. Another, an extremely simple form, is used by the foremen in the spinneries of northern Europe, to direct the changing of the bobbins on the looms. It is made of tin (Fig. 6), and gives out a sound
