The works of Francis Bacon, lord chancellor of England.

OF SOUND AND HEARING. 539
bottom: you shall hear the sound of the tongs every part of the air, not the whole in the whole
knapped in the vessel of silver much more re- air, unless where the opening or passage is ex
sounding than in the wooden one. Whereas, if ceedingly strait. For if one stand in any place
the two vessels were empty, and you knapped utterly closed, so as the sound may not penetrate
the tongs at the same distance, there should be at all, and that in any part soever of a sphere of
little difference, or none. Whence it appears, sound, and there be a small opening made, the
first, that where is no air that can be elided, but articulate voice shall enter through that opening,
only water, sound is given; next, that the sound and in fine through as many openings as you
given by the percussion communicates better shall choose to make through the whole round of'with the vessel through water than through air. the sphere of sound: so as it is man;fest that that
The mouth being close shut, there is made a whole articulation of sound is conveyed entire in
murmur (such as dumb persons use to make) by these minutest parts of the air, not less than if
the throat; if the nostrils likewise be fast closed, the air were at large on every side.
no murmur can be made. Whence it appears, It is, however, to be observed whether sounds
that that sound by the throat is not effected unless proceeding from the greater pulsations of the air
through the opening which lies between the (such as are made by the discharge of ordnance)
throat and the nostrils. become not more exile when they enter by those
small apertures; for it may be that the subtilties
Of the Carriage of Sonzds, and their Direction or of sound shall enter unconfused, but the whole
Spreading; and of the.dr8ea which Sound fills, crash, or roar, not so well.
together and severally. The rays of visible bodies do not strike the
All sound is diffused in a sphere from the place sense, unless they be conveyed through the mec
of the percussion, and fills the whole area of this dium in straight lines, and the interposition of
sphere to a certain limit, upwards, downwards, any opaque, in a right line, intercepts the sight,
sideways, and every way. although every thing else be on all sides wholly
Throughout this orb the sound is loudest close open. But sound, if there be a dilatation or pasto the stroke; thence, in the proportion of the sage, whether by arching over, or by inverted
distance, it grows more faint, until it vanishes. arching downwards, or laterally, or even by windThe limits of this sphere are extended some little ing, perishes not, but arrives. Nevertheless, I
by reason of the quickness of hearing; yet is judge that sound is more strongly carried in
there something uttermost, whither, to the most straight lines, betwixt the pulsations and the enar
delicate sense, sound reaches not. and that by its archings and windings it is some.
There is something, I think, in the direction of what broken; as, if there be a wall betwixt the
the first impulsion; for, if a man should stand in speaker and the hearer, I think that the voice shall
an open pulpit in the fields, and shout, the voice, not be so well heard as if the wall were away.
I judge, should be further heard forwards from the I judge, too, that if the speaker or the hearer be
speaker than behind. So, if ordnance, or a placed at a little distance from the wall, the voice
harquebuss be discharged, I judge that the sound shall be better heard than nigh unto the wall, beshall be further heard before the ordnance or har- cause the arching so much the less departs from
quebuss than behind it. a right line. But this also would be further in
Whether there be any thing in the ascension quired.
of sound upwards, or in the descension of sound If the ear be laid to the one end of any tube or
downwards, which may further sound, or make long hollow trunk, and a voice speak softly at the
it cease nearer, doth not appear. The sound is other opening of the tube, such a voice shall be
indeed well heard, if one speak from a high win- heard, which, being as softly spoken in the air at
dow or turret, by those who stand upon. the large, should not arrive, nor be heard. Whence
ground; and, contrariwise, being uttered by those it is clear, that that confining of the air helps tothat stand upon the ground from the window or the conveying of the voice, without confusion.
turret, but by whether more easily, or further off, It is also a common opinion, that, other things
let better inquiry be made. being equal, the voice is better heard within doors
Pulpits are used for speaking in assemblies, than abroad; hut whether the voice be better
and generals did -usually speak standing upon heard when the ear is out of doors, and the voice.
mounds of sods; yet is it is no wise hence con- within the house; or contrariwise, when the voice
firmed that sound easilier descends than it rises, is out of doors, and the ear within the hous% may
since the cause hereof may be the liberty of the be further inquired; albeit herein also the opinion
air in the higher place, not thronged or hindered, is received, that what is abroad is hetter heard
as below amongst the crowd, but not the readier within doors, than what is within, abroad.
motion downwards. Therefore, let not the con? It is common to hearing and slght, and, indeed,
templation stay in ihis instance, but let a trial be in a certain measure, to the other senses, that the.
made where other things are equal. attention of the perceiving mind, and express di
The power of the sound is received whole in rection to perceivilga help spotewhat to perceiN