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principal cause of violent motion, though unobserved, passeth without sound; for that sound that is heard sometimes is produced only by the breaking of the air, and not by the impulsion of the parts. So it is manifest, that where the anterior body giveth way, as fast as the posterior cometh on, it maketh no noise, be the motion never so great or swift.

116. Air open, and at large maketh no noise, except it be sharply percussed; as in the sound of a string, where air is percussed by a hard and stiff body, and with a sharp loose: for if the string be not strained, it maketh no noise. But where the air is pent and straitened, there breath or other blowing, which carry but a gentle pereussion, suffice to create sound; as in pipes and wind-instruments. But then you must note, that in recorders, which go with a gentle breath, the concave of the pipe, were it not for the fipple that straiteneth the air, much more than the simple concave, would yield no sound. For as for other wind-instruments, they require a forcible breath; as trumpets, cornets, hunters' horns, &c., which appeareth by the blown cheeks of him that windeth them. Organs also are blown with a strong wind by the bellows. And note again, that some kind of wind-instruments are blown at a small hole in the side, which straiteneth the breath at the first entrance; the rather, in respect of the traverse and stop above the hole, which performeth the fipple's part; as it is seen in flutes and fifes, which will not give sound by a blast at the end, as recorders, &c., do. Likewise in all whistling, you contract the mouth; and to make it more sharp, men sometimes use their finger. But in open air, if you throw a stone or a dart, they give no sound; no more do bullets, except they happen to be a little hollowed in the casting; which hollowness penneth the air: nor yet arrows, except they be rufled in their feathers, which likewise penneth the air. As for small whistles or shepherds' oaten pipes, they give a sound because of their extreme slenderness, whereby the air is more pent than in a wider pipe. Again, the voices of men and living creatures pass through the throat, which penneth the breath. As for the Jews-harp, it is a sharp percussion; and besides, hath the advantage of penning the

air in the mouth.

117. Solid bodies, if they be very softly percussed, give no sound; as when a man treadeth very softly upon boards. So chests or doors in fair weather, when they open easily, give no sound. And cart-wheels squeak not when they are liquored.

118. The flame of tapers or candles, though it be a swift motion and breaketh the air, yet passeth without sound. Air in ovens, though, no doubt, it doth, as it were, boil and dilate itself, and is repercussed; yet it is without noise.

119. Flame percussed by air giveth a noise;

as in blowing of the fire by bellows; greater than if the bellows should blow upon the air itself. And so likewise flame percussing the air strongly, as when flame suddenly taketh and openeth, giveth a noise; so great flames, while the one impelleth the other, give a bellowing sound.

120. There is a conceit runneth abroad, that there should be a white powder, which will discharge a piece without noise; which is a dangerous experiment if it should be true: for it may cause secret murders. But it seemeth to me impossible; for if the air pent be driven forth, and strike the air open, it will certainly make a noise. As for the white powder, if any such thing be, that may extinguish or dead the noise, it is like to be a mixture of petre and sulphur, without coal. For petre alone will not take fire. And if any man think that the sound may be extinguished or deaded by discharging the pent air, before it cometh to the mouth of the piece and to the open air, that is not probable; for it will make more divided sounds: as if you should make a crossbarrel hollow through the barrel of a piece, it may be it would give several sounds, both at the nose, and at the sides. But I conceive, that if it were possible to bring to pass, that there should be no air pent at the mouth of the piece, the bullet might fly with small or no noise. For first, it is certain, there is no noise in the percussion of the flame upon the bullet. Next, the bullet, in piercing through the air, maketh no noise as hath been said. And then, if there be no pent air that striketh upon open air, there is no cause of noise; and yet the flying of the bullet will not be stayed. For that motion, as hath been oft said, is in the parts of the bullet, and not in the air. So as trial must be made by taking some small concave of metal, no more than you mean to fill with powder, and laying the bullet in the mouth of it, half out into the open air.

121. I heard it affirmed by a man that was a great dealer in secrets, he was but vain, that there was a conspiracy, which himself hindered, to have killed Queen Mary, sister to Queen Elizabeth, by a burning-glass, when she walked in St. James's park, from the leads of the house. But thus much, no doubt, is true; that if burningglasses could be brought to a great strength, as they talk generally of burning-glasses that are able to burn a navy, the percussion of the air alone, by such a burning-glass, would make no noise: no more than is found in coruscations and lightnings without thunders.

122. I suppose, that impression of the air with sounds asketh a time to be conveyed to the sense, as well as the impressing of species visible; or else they will not be heard. And therefore, as the bullet moveth so swift that it is invisible; so the same swiftness of motion maketh it inaudible:

for we see, that the apprehension of the eye is which pass through the air, or other bodies, withquicker than that of the ear.

123. All eruptions of air, though small and slight, give an entity of sound, which we call crackling, puffing, spitting, &c. as in bay-salt, and bay-leaves, cast into the fire; so in chestnuts, when they leap forth of the ashes; so in green wood laid upon the fire, especially root; so in candles, that spit flame if they be wet; so in rasping, sneezing, &c. so in a rose leaf gathered together into the fashion of a purse, and broken upon the forehead, or back of the hand, as child

ren use.

Experiments in consort touching production, conservation, and delation of sounds; and the office of the air therein.

out any local motion of the air; either at the first, or after. But you must attentively distinguish between the local motion of the air, which is but vehiculum causæ," a carrier of the sounds, and the sounds themselves, conveyed in the air. For as to the former, we see manifestly that no sound is produced, no not by air itself against other air, as in organs, &c. but with a perceptible blast of the air; and with some resistance of the air strucken. For even all speech, which is one of the gentlest motions of the air, is with expulsion of a little breath. And all pipes have a blast, as well as a sound. We see also manifestly, that sounds are carried with wind: and therefore sounds will be heard further with the wind, than against the wind; and likewise do rise and fall with the in124. The cause given of sound, that it should tension or remission of the wind. But for the be an elision of the air, whereby if they mean impression of the sound, it is quite another thing, any thing, they mean a cutting or dividing, or else and is utterly without any local motion of the air, an attenuating of the air, is but a term of igno- perceptible; and in that resembleth the species rance; and the notion is but a catch of the wit visible: for after a man hath lured, or a bell is upon a few instances; as the manner is in the rung, we cannot discern any perceptible motion philosophy received. And it is common with at all in the air along as the sound goeth; but men, that if they have gotten a pretty expression only at the first. Neither doth the wind, as far by a word of art, that expression goeth current; as it carrieth a voice, with the motion thereof, conthough it be empty of matter. This conceit of found any of the delicate and articulate figurations elision appeareth most manifestly to be false, in of the air, in variety of words. And if a man that the sound of a bell, string, or the like, con- speak a good loudness against the flame of a tinueth melting some time after the percussion; candle, it will not make it tremble much; though but ceaseth straightways, if the bell, or string, be most when those letters are pronounced which touched and stayed: whereas, if it were the eli- contract the mouth; as F. S. V. and some others. sion of the air that made the sound, it could not But gentle breathing, or blowing without speakbe that the touch of the bell or string should ex-ing, will move the candle far more. And it is tinguish so suddenly that motion caused by the the more probable, that sound is without any local elision of the air. This appeareth yet more mani- motion of the air, because as it differeth from the festly by chiming with a hammer upon the out- sight, in that it needeth a local motion of the air side of a bell: for the sound will be according to at first; so it paralleleth in so many other things the inward concave of the bell; whereas the eli- with the sight, and radiation of things visible; sion or attenuation of the air cannot be but only which without all question induce no local mobetween the hammer and the outside of the bell. tion in the air, as hath been said. So again, if it were an elision, a broad hammer, and a bodkin, struck upon metal, would give a diverse tone, as well as a diverse loudness: but they do not so; for though the sound of the one be louder, and of the other softer, yet the tone is the same. Besides, in echoes, whereof some are as loud as the original voice, there is no new elision, but a repercussion only. But that which convinceth it most of all is, that sounds are generated where there is no air at all. But these and the like conceits, when men have cleared their understanding by the light of experience, will scatter and break up like a mist.

125. It is certain, that sound is not produced at the first, but with some local motion of the air, or flame, or some other medium; nor yet without some resistance, either in the air or the body percussed. For if there be a mere yielding or cession. it produceth no sound; as hath been said. And therein sounds differ from light and colours,

126. Nevertheless it is true, that upon the noise of thunder, and great ordnance, glass windows will shake; and fishes are thought to be frayed with the motion caused by noise upon the water. But these effects are from the local motion of the air, which is a concomitant of the sound, as hath been said, and not from the sound.

127. It hath been anciently reported, and is still received, that extreme applauses and shouting of people assembled in great multitudes, have so rarified and broken the air that birds flying over have fallen down, the air being not able to support them. And it is believed by some, that great ringing of bells in populous cities hath chased away thunder; and also dissipated pestilent air: all which may be also from the concussion of the air, and not from the sound.

128. A very great sound, near hand, hath strucken many deaf; and at the instant they have found, as it were, the breaking of a skin or parch

nent in their ear: and myself standing near one that lured loud and shrill, had suddenly an offence, as if somewhat had broken or been dislocated in my ear; and immediately after a loud ringing, not an ordinary singing or hissing, but far louder and differing, so as I feared some deafness. But after some half quarter of an hour it vanished. This effect may be truly referred unto the sound for as is commonly received, an overpotent object doth destroy the sense; and spiritual species, both visible and audible, will work upon the sensories, though they move not any other body. 129. In delation of sounds, the enclosure of them preserveth them, and causeth them to be heard further. And we find in rolls of parchment or trunks, the mouth being laid to the one end of the roll of parchment or trunk, and the ear to the other, the sound is heard much farther than in the open air. The cause is, for that the sound spendeth, and is dissipated in the open air; but in such concaves it is conserved and contracted. So also in a piece of ordnance, if you speak in the touchhole, and another lay his ear to the mouth of the piece, the sound passeth and is far better heard than in the open air.

130. It is further to be considered, how it proveth and worketh when the sound is not enclosed all the length of its way, but passeth partly through open air; as where you speak some distance from a trunk; or where the ear is some distance from the trunk at the other end; or where both mouth and ear are distant from the trunk. And it is tried, that in a long trunk of some eight or ten foot, the sound is holpen, though both the mouth and the ear be a handful or more from the ends of the trunk; and somewhat more holpen, when the ear of the hearer is near, than when the mouth of the speaker. And it is certain, that the voice is better heard in a chamber from abroad, than abroad from within the chamber.

pair of tongs some depth within the water, and you shall hear the sound of the tongs well and not much diminished; and yet there is no air at all present.

134. Take one vessel of silver, and another of wood, and fill each of them full of water, and then knap the tongs together, as before, about a handful from the bottom, and you shall find the sound much more resounding from the vessel of silver than from that of wood: and yet if there be no water in the vessel, so that you knap the tongs in the air, you shall find no difference between the silver and the wooden vessel. Whereby, beside the main point of creating sound without air, you may collect two things: the one, that the sound communicateth with the bottom of the vessel; the other, that such a communication passeth far better through water than air.

135. Strike any hard bodies together in the midst of a flame; and you shall hear the sound with little difference from the sound in the air.

136. The pneumatical part which is in all tangible bodies, and hath some affinity with the air, performeth, in some degree, the parts of the air; as when you knock upon an empty barrel, the sound is in part created by the air on the outside; and in part by the air in the inside: for the sound will be greater or lesser as the barrel is more empty or more full; but yet the sound participateth also with the spirit in the wood through which it passeth, from the outside to the inside: and so it cometh to pass in the chiming of bells on the outside; where also the sound passeth to the inside: and a number of other like instances, whereof we shall speak more when we handle the communication of sounds.

137. It were extreme grossness to think, as we have partly touched before, that the sound in strings is made or produced between the hand and the string, or the quill and the string, or the 131. As the enclosure that is round about and bow and the string, for those are but "vehicula entire, preserveth the sound; so doth a semi-con- motus," passages to the creation of the sound, the cave, though in a less degree. And therefore, if sound being produced between the string and the you divide a trunk, or a cane into two, and one air; and that not by any impulsion of the air from speak at the one end, and you lay your ear at the the first motion of the string; but by the return other, it will carry the voice farther than in the or result of the string, which was strained by the air at large. Nay further, if it be not a full semi-touch, to his former place: which motion of result concave, but if you do the like upon the mast of a ship, or a long pole, or a piece of ordnance, though one speak upon the surface of the ordnance, and not at any of the bores, the voice will be heard farther than in the air at large.

132. It would be tried, how, and with what proportion of disadvantage the voice will be carried in a horn, which is a line arched; or in a trumpet, which is a line retorted; or in some pipe that were sinuous.

133. It is certain, howsoever it cross the received opinion, that sounds may be created without ail, though air be the most favourable deferent of sounds. Take a vessel of water, and knap a

is quick and sharp; whereas the first motion is soft and dull. So the bow tortureth the string continually, and thereby holdeth it in a continual trepidation.

Experiments in consort touching the magnitude and exility and damps of sounds.

138. Take a trunk, and let one whistle at the one end, and hold your ear at the other, and you shall find the sound strike so sharp as you can scarce endure it. The cause is, for that sound diffuseth itself in round, and so spendeth itself; but if the sound, which would scatter in open air, be made to go all into a canal, it must needs give

greater force to the sound. And so you may note, that enclosures do not only preserve sound, but also increase and sharpen it.

139. A hunter's horn being greater at one end than at the other, doth increase the sound more than if the horn were all of an equal bore. The cause is, for that the air and sound being first contracted at the lesser end, and afterwards having more room to spread at the greater end, to dilate themselves; and in coming out strike more air; whereby the sound is the greater and baser. And even hunter's horns, which are sometimes made straight, and not oblique, are ever greater at the lower end. It would be tried also in pipes, being made far larger at the lower end; or being made with a belly towards the lower end, and then issuing into a straight concave again.

140. There is in St. James's fields a conduit of brick, unto which joineth a low vault; and at the end of that a round house of stone; and in the brick conduit there is a window; and in the round house a slit or rift of some little breadth: if you cry out in the rift, it will make a fearful roaring at the window. The cause is the same with the former; for that all concaves, that proceed from more narrow to more broad, do amplify the sound at the coming out.

141. Hawks' bells, that have holes in the sides, give a greater ring, than if the pellet did strike upon brass in the open air. The cause is the same with the first instance of the trunk; namely, for that the sound enclosed with the sides of the bell cometh forth at the holes unspent and more strong.

142. In drums, the closeness round about, that preserveth the sound from dispersing, maketh the noise come forth at the drum-hole far more loud and strong than if you should strike upon the like skin extended in the open air. The cause is the same with the two precedent.

143. Sounds are better heard, and farther off, in an evening or in the night, than at the noon or in the day. The cause is, for that in the day, when the air is more thin, no doubt, the sound pierceth better; but when the air is more thick, as in the night, the sound spendeth and spreadeth abroad less and so it is a degree of enclosure. As for the night, it is true also that the general silence helpeth.

144. There be two kinds of reflections of sound; the one at distance, which is the echo; wherein the original is heard distinctly, and the reflection also distinctly; of which we shall speak hereafter: the other in concurrence; when the sound reflecting, the reflection being near at hand, returneth immediately upon the original, and so iterateth it not, but amplifieth it. Therefore we see, that music upon the water soundeth more; and so Jikewise music is better in chambers wainscotted than hanged.

145. The strings of a lute, or viol, or virginals,

do give a far greater sound, by reason of the knot, and board, and concave underneath, than if there were nothing but only the flat of a board, without that hollow and knot, to let in the upper air into the lower. The cause is the communication of the upper air with the lower, and penning of both from expense or dispersing.

146. An Irish harp hath open air on both sides of the strings: and it hath the concave or belly not along the strings, but at the end of the strings. It maketh a more resounding sound than a bandora, orpharion, or citter, which have likewise wire strings. I judge the cause to be, for that open air on both sides helpeth, so that there be a concave; which is therefore best placed at the end.

147. In a virginal, when the lid is down, it maketh a more exile sound than when the lid is open. The cause is, for that all shutting in of air, where there is no competent vent, dampeth the sound: which maintaineth likewise the former instance; for the belly of the lute or viol doth pen the air somewhat.

148. There is a church at Gloucester, and, as I have heard, the like is in some other places, where if you speak against a wall softly, another shall hear your voice better a good way off, than near at hand. Inquire more particularly of the frame of that place. I suppose there is some vault, or hollow, or aisle, behind the wall, and some passage to it towards the farther end of that wall against which you speak; so as the voice of him that speaketh slideth along the wall, and then entereth at some passage, and communicateth with the air of the hollow; for it is preserved somewhat by the plain wall; but that is too weak to give a sound audible, till it hath communicated with the back air.

149. Strike upon a bow-string, and lay the horn of the bow near your ear, and it will increase the sound, and make a degree of a tone. The cause is, for that the sensory, by reason of the close holding, is percussed before the air disperseth. The like is, if you hold the horn betwixt your teeth: but that is a plain delation of the sound from the teeth to the instrument of hearing; for there is a great intercourse between those two parts; as appeareth by this, that a harsh grating tune setteth the teeth on edge. The like falleth out, if the horn of the bow be put upon the temples; but that is but the slide of the sound from thence to the ear.

150. If you take a rod of iron or brass, and hold the one end to your ear, and strike upon the other, it maketh a far greater sound than the like stroke upon the rod, made not so contiguous to the ear. By which, and by some other instances that have been partly touched, it should appear, that sounds do not only slide upon the surface of a smooth body, but do also communicate with the spirits, that are in the pores of the body.

151. I remember in Trinity College in Cam

bridge, there was an upper chamber, which being | name aloud, that all the shore rang of it; and thought weak in the roof, it was supported by a that Hylas from within the water answered his pillar of iron of the bigness of one's arm in the midst of the chamber; which if you had struck, it would make a little flat noise in the room where it was struck, but it would make a great bomb in the chamber beneath.

152. The sound which is made by buckets in a well, when they touch upon the water, or when they strike upon the side of the well, or when two buckets dash the one against the other, these sounds are deeper and fuller than if the like percussion were made in the open air. The cause is the penning and enclosure of the air in the concave of the well.

153. Barrels placed in a room under the floor of a chamber make all noises in the same chamber more full and resounding.

So that there be five ways, in general, of majoration of sounds: enclosure simple; enclosure with dilatation; communication; reflection concurrent; and approach to the sensory.

154. For exility of the voice or other sounds; it is certain that the voice doth pass through solid and hard bodies if they be not too thick: and through water, which is likewise a very close body, and such a one as letteth not in air. But then the voice, or other sound, is reduced by such passage to a great weakness or exility. If therefore you stop the holes of a hawk's bell, it will make no ring, but a flat noise or rattle. And so doth the "aetites" or eagle-stone, which hath a little stone within it.

155. And as for water, it is a certain trial: let a man go into a bath, and take a pail, and turn the bottom upwards, and carry the mouth of it even, down to the level of the water, and so press ⚫ it down under the water some handful and a half, still keeping it even that it may not tilt on either side, and so the air get out: then let him that is in the bath dive with his head so far under water, as he may put his head into the pail, and there will come as much air bubbling forth as will make room for his head. Then let him speak, and any that shall stand without shall hear his voice plainly; but yet made extreme sharp and exile, like the voice of puppets: but yet the articulate sounds of the words will not be confounded. Note, that it may be much more handsomely done, if the pail be put over the man's nead above the water, and then he cower down, and the pail be pressed down with him. Note, that a man must kneel or sit, that he may be lower than the water. A man would think that the Sicilian poet had knowledge of this experiment; for he said, that Hercules's page, Hylas, went with a water-pot to fill it at a pleasant fountain that was near the shore, and that the nymph of the fountain fell in love with the boy, and pulled him under water, keeping him alive; and that Hercules missing his page, called him by his

master, but, that which is to the present purpose, with sc small and exile a voice, as Hercules thought he had been three miles off, when the fountain, indeed, was fast by.

156. In lutes and instruments of strings, if you stop a string high, whereby it hath less scope to tremble, the sound is more treble, but yet more dead.

157. Take two saucers, and strike the edge of the one against the bottom of the other, within a pail of water; and you shall find, that as you put the saucers lower and lower, the sound groweth more flat; even while part of the saucer is above the water; but that flatness of sound is joined with a harshness of sound; which no doubt is caused by the inequality of the sound which cometh from the part of the saucer under water, and from the part above. But when the saucer is wholly under water, the sound becometh more clear, but far more low, and as if the sound came from afar off.

158. A soft body dampeth the sound much more than a hard; as if a bell hath cloth or silk wrapped about it, it deadeth the sound more than if it were wood. And therefore in clericals the keys are lined; and in colleges they use to line tablemen.

159. Trial was made in a recorder after these several manners. The bottom of it was set against the palm of the hand; stopped with wax round about; set against a damask cushion; thrust into sand; into ashes; into water, half an inch under the water; close to the bottom of a silver basin; and still the tone remained: but the bottom of it was set against a woollen carpet; a lining of plush; a lock of wool, though loosely put in; against snow; and the sound of it was quite deaded, and but breath.

160. Iron hot produceth not so full a sound as when it is cold, for while it is hot, it appeareth to be more soft and less resounding. So likewise warm water, when it falleth, maketh not so full a sound as cold, and I conceive it is softer, and nearer the nature of oil, for it is more slippery, as may be perceived in that it scoureth better.

161. Let there be a recorder made with two fipples, at each end one: the trunk of it of the length of two recorders, and the holes answerable towards each end, and let two play the same lesson upon it as in unison; and let it be noted whether the sound be confounded, or amplified, or dulled. So likewise let a cross be made of two trunks, throughout, hollow, and let two speak, or sing, the one longways, the other traverse; and let two hear at the opposite ends, and note whether the sound be confounded, amplified, or dulled. Which two instances will also give light to the mixture of sounds, whereof we shall speak hereafter.

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