Page:Young - Outlines of experiments and inquiries respecting sound and light (1800).djvu/17

 {| cellspacing=0 cellpadding=3 A, B, C, and D, as in Table. .8 1.2 1.8 2. 4. 3. 1.5 1. .5 .0 1. 2. 3. .2 .4 .6 .2 .35 .5 .2 .34 .5
 * colspan=10 |.
 * colspan=3 |.
 * A
 * colspan=4 |1.15
 * colspan=3 |3.3
 * 4.
 * rowspan=4 |Diameter of the tube .3.
 * rowspan=4 |Diameter of the tube .3.
 * A
 * B
 * rowspan=4 |A is the pressure. B, the distance of the apex of the cone from the orifice of a tube .1 in diameter.
 * B
 * .15
 * .3
 * .5
 * 1.
 * .06
 * .15
 * 1.
 * .06
 * rowspan=3 |.4
 * rowspan=3 |.4
 * rowspan=3 |6.
 * C
 * D
 * D
 * D
 * D
 * D
 * D
 * D
 * D
 * .5
 * .5
 * .5
 * .1
 * .1
 * .1

.13 .2

.1 .15

.1 .15

.125 .18

.1
 * }

A tube about the tenth of an inch in diameter, with a lateral orifice half an inch from its end, filed rather deeper than the axis of the tube, Fig. 27, was inserted at the apex of a conical cavity containing about twenty cubic inches of air, and luted perfectly tight: by blowing through the tube, a sound nearly in unison with the tenor C was produced. By gradually increasing the capacity of the cavity as far as several gallons, with the same mouth-piece, the sound, although faint, became more and more grave, till it was no longer a musical note. Even before this period a kind of trembling was distinguishable; and this, as the cavity was still further increased, was changed into a succession of distinct puffs, like the sound produced by an explosion of air from the lips; as slow, in some instances, as 4 or 3 in a second. These were undoubtedly the single vibrations, which, when repeated with sufficient frequency, impress on the auditory nerve the sensation of a continued sound. On forcing a current of smoke through the tube, the vibratory motion of the stream, as it passed out at the lateral orifice, was evident to the eye; although, from various circumstances, the quantity and direction of its motion could not be subjected to