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)

    58/494 (page 36)
    researches of Dulong, who employed in his experiments a method which shall be subsequently explained:— Velocity of Sound in Gases at the Temperatube of 0° C. Velocity Air 1,092 foot. Oxygen 1,040 „ Hydrogen 4,164 „ Carbonic acid .... 858 „ Carbonic oxide .... 1,107 „ Protoxide of nitrogen . . . 859 „ defiant gas .... 1,030 „ According to theory, the velocities of sound in oxygen and hydrogen are inversely proportional to the square roots of the densities of the two gases. We here find this theo- retic deduction verified by experiment. Oxygen being six- teen times heavier than hydrogen, the velocity of sound in the latter gas ought, according to the above law, to be four times its velocity in the former ; hence the velocity in oxygen being 1,040, in hydrogen calculation would make it 4,160. Experiment, we see, makes it 4,164. The velocity of sound in liquids may be determined theoretically, as Newton determined its velocity in air; for the density of a liquid is easily determined, and its elas- ticity can be measured by subjecting it to compression. In the case of water, the calculated and the observed velocities agree so closely as to prove that the changes of temperature produced by a sound-wave in water have no sensible influence upon the velocity. In a series of me- morable experiments in the lake of Geneva, MM. Colladon and Sturm determined the velocity of sound through water, and made it 4,708 feet a second. By a mode of experiment which you will subsequently be able to com- prehend, the late M. Wertheim determined the velocity through various liquids, and in the following table I have collected his results :—