Sound / by John Tyndall.

  • Tyndall, John, 1820-1893.
Date:
1883
Catalogue details

Licence: Public Domain Mark

Credit: Sound / by John Tyndall. Source: Wellcome Collection.

Provider: This material has been provided by UCL Library Services. The original may be consulted at UCL (University College London)

    463/494 (page 439)
    5. Other tones act with less energy on the jet, and some produce no sensible effect. When a jet is made to ascend obliquely, so that the discon- tinuous part appears scattered into a kind of sheaf w. the same vertical plane, M. Savart found,— a. That under the influence of vibrations of a determinate period, this sheaf may form itself into two distinct jets, each possessing regularly-disposed ventral segments and nodes; some- times with a different node, the sheaf becomes replaced by three jets. b. The note which produces the greatest shortening of the continuous part, always reduces the whole to a single jet, pre- senting a perfectly regular system of ventral segments and nodes. In the last memoir of M. Savart—a posthumous one, pre- sented to the Academy of Sciences of Paris, by M. Arago, in 1853,1—several remarkable acoustic phenomena are noticed in relation to the musical tones produced by the efflux of liquids through short tubes. When certain precautions and conditions are observed (which are minutely detailed by this able experi- mentalist), the discharge of the liquid gives rise to a succession of musical tones of great intensity and of a peculiar quality, somewhat analogous to that of the human voice. That these notes were not produced by the descending drops of the liquid vein, was proved by permitting it to discharge itself into a vessel of water, while the orifice was below the surface of the latter. In this case the jet of liquid must have been continuous, but nevertheless the notes were produced. These unexpected results have been entirely confirmed by the more recent experi- ments of Prof. Tyndall.2 According to the researches of M. Plateau„all the phenomena of the influence of vibrations on jets of liquid are referable to the conflict between the vibrations and the forces of figure (' forces figuratrices'). If the physical fact is admitted—and it seems to be indisputable—that a liquid cylinder attains a limit of gtabiMty when the proportion between its length and its diameter is in the ratio of 22 to 7, it is almost a physical 1 ComptU Rendus for August 185.'5. Also Phil. Mag. 8. 4, vol. vii. p. 18B, 18.5 J.