An account of experiments on the velocity of sound, made in Holland

Abstract

After adverting to the difference between the celerity of sound, as deduced by theory and found by experiment; and to Laplace’s explanation of the cause of that difference, and his corrections of the Newtonian formula,—the authors proceed to consider the influence of the variable force of wind upon its velocity, and state their mode of annihilating such cause of error. They then detail their own experiments, for which they selected two open and elevated spots in the plains of Utrecht, distinctly visible from each other, and distant about 9664 fathoms. They measured the interval between seeing the light and hearing the sound by clocks with conical pendulums, which divide the 24 hours into 10,000,000 parts, and one of the indexes of which gives one 100th part of a decimal second. Each station was also furnished with a good barometer, several accurate thermometers and excellent telescopes, and the humidity of the air was determined by Daniell’s hygrometer. The authors then describe the means which they adopted to insure the simultaneous firing of shots at both stations, and by which they succeeded in bringing them within 1" or 2" of each other, and enter at considerable length into the details of their different experiments, the results of which are given in several tables annexed to this paper; among which will be found one exhibiting a general view of the results of the experiments of those different philosophers who have investigated this subject. In conclusion, it appears from their researches that at the temperature of 32°, the velocity of sound is 1089·7445 English feet per sexagesimal second.