Of SOUND.

My design being to explain the nature of Music, it will not be improper to inquire first concerning the cause of Sound. Although I cannot hope to give full satisfaction—because our senses lack the precision original: "subtilty" to discover the motions of the minute parts of the air upon which it depends—yet perhaps I may assign a possible cause for the production of Sound. The knowledge of this will give some ease to the wondering philosopher In this context, "philosopher" refers to a student of natural science.; and if I have the good fortune to show a probable cause, the curious The "curious" refers to those interested in scientific inquiry. will be satisfied without further inquiry, which is the only benefit they can gain from speculations of this nature.

No.

1.

The phenomena of sound which I consider significant are these:
1. It may be produced in the Torricellian vacuum original: "Torricellian vacuity"; the space created at the top of a barometer, which early scientists used to test if sound could travel without air..
2. It causes motion in solid bodies.
3. It is diminished by the placement of solid bodies in its path.
4. If the bodies placed in between are very thick, its passage is wholly obstructed.
5. It seems to reach the ear in straight lines, even when the object is positioned so that it cannot travel in a direct line to the ear.
6. When the air is still, its reach is spherical.
7. When there is a wind, that sphere is enlarged in the direction the wind blows and diminished on the opposite side.
8. It does not arrive at the ear instantly, but considerably slower than sight.
9. It travels as quickly against the wind as with it, though it is not as loud nor does it travel as far.

There are many other observable appearances, and more will daily occur to the curious through experiments; however, the consideration of these qualities of sound and the visible actions that produce it has led me to entertain the following hypothesis.