| Table ix. | Table x. | |||||||||||
| A | 1.15 | 3.3 | 4. | Diameter of the tube .3. A, B, C, and D, as in Table vii. |
A | B | 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 | .4 .8 1.2 1.8 2. 4. |
6. 3. 1.5 1. .5 .0 | ||
| C | D | D | D | D | D | D | D | D | ||||
| .5 1. 2. 3. |
.1 .2 .4 .6 |
.1 .2 .35 .5 |
.1 .2 .34 .5 |
.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
