The Travelling Of Sound Experimentally Proved

There is probably no substance which is not in some measure a

conductor of sound; but sound is much enfeebled by passing from one

medium to another. If a man, stopping one of his ears with his finger,

stop the other also by pressing it against the end of a long stick,

and a watch be applied to the opposite end of the stick, or a piece of

timber, be it ever so long, the beating of the watch will be

distinctly heard; whe eas, in the usual way, it can scarcely be heard

at the distance of fifteen or eighteen feet. The same effect will take

place if he stops both his ears with his hands, and rest his teeth,

his temple, or the gristly part of one of his ears against the end of

a stick. Instead of a watch, a gentle scratch may be made at one end

of a pole or rod, and the person who keeps his ear in close contact

with the other end of the pole, will hear it very plainly. Thus,

persons who are dull of hearing, may, by applying their teeth to some

part of a harpsichord, or other sounding body, hear the sound much

better than otherwise.



If a person tie a strip of flannel about a yard long, round a poker,

then press with his thumbs and fingers the ends of the flannel into

his ears, while he swings the poker against an iron fender, he will

hear a sound very like that of a large church bell.