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one end, and you lay your ear at the other, it will carry the voice further, than in the air at large. Nay further, if it be not a full semi-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 further than in the air at large.
132. It would be tried, how, and with what proportion of disadvantage the voice will be carried in an 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 air, though air be the most favourable deferent of sounds. Take a vessel of water, and knap a 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 an 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 tangi. ble bodies, and hath some affinity with the air, per formeth, 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 bow and the string, for those are but vehicula motus, passages to the creation of the sound, the sound being produced between the string and the air; and that not by any impulsion of the air from the first motion of the string; but by the return or result of the string, which was strained by the touch, to his former place: which motion of result 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 inclosures 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, do dilate themselves; and in coming out strike more air; whereby the sound is the greater and baser. And even hunters 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 Saint 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 inclosed 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 inclosure. As for the night, it is true also that the general silence helpeth.
144. THERE be two kinds of reflexions of sounds; the one at distance, which is the echo; wherein the original is heard distinctly, and the reflexion also distinctly; of which we shall speak hereafter: the other in concurrence; when the sound reflecting, the reflexion being near at hand, returneth immediately upon the original, and so iterateth it not, but ampli
fieth it. Therefore we see, that music upon the water soundeth more; and so likewise 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 expence 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 cittern, which have likewise wirestrings. 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 isle, 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
The cause is, close holding, The like is, if but that is a
sound, and make a degree of a tone. for that the sensory, by reason of the is percussed before the air disperseth. you hold the horn betwixt your teeth: 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 Cambridge, there was an upper chamber, which being thought weak in the roof of it, was supported by a 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 inclosure 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: inclosure simple; inclosure with dilatation; communication; reflexion concurrent; and approach to the sensory.