tion of the outward air with the air within, would be little or none: but only you shall hear the noise of the outward knock, as if the vessel were full.

213. It is certain, that in the passage of sounds through hard bodies the spirit or pneumatical part of the hard body itself doth co-operate; but much better when the sides of that hard body are struck, than when the percussion is only within, without touch of the sides. Take therefore a hawk's bell, the holes stopped up, and hang it by a thread within a bottle glass, and stop the mouth of the glass very close with wax; and then shake the glass, and see whether the bell give any sound at all, or how weak: but note, that you must instead of the thread take a wire; or else let the glass have a great belly; lest when you shake the bell, it dash upon the sides of the glass.

214. IT is plain, that a very long and downright arch for the sound to pass, will extinguish the sound quite; so that that sound, which would be heard over a wall, will not be heard over a church; nor that sound, which will be heard if you stand some distance from the wall, will be heard if you stand close under the wall.

215. SOFT and foraminous bodies, in the first creation of the sound, will dead it; for the striking against cloth or furr will make little sound; as hath been said: but in the passage of the sound, they will admit it better than harder bodies; as we see, that curtains and hangings will not stay the sound much; but glass windows, if they be very close, will check a sound more than the like thickness of cloth. We see also in the rumbling of the belly, how easily the sound passeth through the guts and skin.

216. It is worthy the inquiry, whether great sounds, as of ordnance or bells, become not more weak and exile when they pass through small crannies. For the subtilties of articulate sounds, it may be, may pass through small crannies not confused; but the magnitude of the sound, perhaps, not so well.

Experiments in consort touching the medium of sounds. 217. THE mediums of sounds are air; soft and porous bodies; also water. And hard bodies refuse not altogether to be mediums of sounds. But all of them are dull and unapt deferents, except the air.

218. IN air, the thinner or drier air carrieth not the sound so well as the more dense; as appeareth in night sounds and evening sounds, and sounds in moist weather and southern winds. The reason is already mentioned in the title of majoration of sounds; being for that thin air is better pierced; but thick air preserveth the sound better from waste: let further trial be made by hollowing in mists and gentle showers; for, it may be, that will somewhat dead the sound.

219. How far forth flame may be a medium of sounds, especially of such sounds as are created by air, and not betwixt hard bodies, let it be tried in speaking where a bonfire is between; but then you must allow for some disturbance the noise that the flame itself maketh.

:

220. WHETHER any other liquors, being made mediums, cause a diversity of sound from water, it may be tried as by the knapping of the tongs; or striking of the bottom of a vessel, filled either with milk or with oil; which though they be more light, yet are they more unequal bodies than air.

Of the natures of the mediums we have now spoken; as for the disposition of the said mediums, it doth consist in the penning, or not penning of the air; of which we have spoken before in the title of delation of sounds: it consisteth also in the figure of the concave through which it passeth; of which we will speak next.

Experiments in consort, what the figures of the pipes, or concaves, or the bodies deferent, conduce to the sounds.

How the figures of pipes, or concaves, through which sounds pass, or of other bodies deferent, conduce to the variety and alteration of the sounds; either in respect of the greater quantity, or less quantity of air,

which the concaves receive; or in respect of the carrying of sounds longer and shorter way; or in respect of many other circumstances; they have been touched, as falling into other titles. But those figures which we now are to speak of, we intend to be, as they concern the lines through which the sound passeth; as straight, crooked, angular, circular, etc.

221. THE figure of a bell partaketh of the pyramis, but yet coming off and dilating more suddenly. The figure of a hunter's horn and cornet is oblique; yet they have likewise straight horns; which, if they be of the same bore with the oblique, differ little in sound, save that the straight require somewhat a stronger blast. The figures of recorders, and flutes, and pipes, are straight; but the recorder hath a less bore and a greater, above and below. The trumpet hath the figure of the letter S: which maketh that purling sound, etc. Generally the straight line hath the cleanest and roundest sound, and the crooked, the more hoarse and jarring.

$222. Of a sinuous pipe that may have some four flexions, trial would be made. Likewise of a pipe. made like a cross, open in the midst. And so likewise of an angular pipe: and see what will be the effects of these several sounds. And so again of a circular pipe; as if you take a pipe perfect round, and make a hole whereinto you shall blow, and another hole not far from that; but with a traverse or stop between them; so that your breath may go the round of the circle, and come forth at the second hole. You may try likewise percussions of solid bodies of several figures; as globes, flats, cubes, crosses, triangles, etc. and their combinations, as flat against flat, and convex against convex, and convex against flat, etc. and mark well the diversities of the sounds. Try also the difference in sound of several crassitudes of hard bodies percussed; and take knowledge of the diversities of the sounds. I myself have tried, that a bell of gold yieldeth an excellent sound, not inferior to that of silver or brass, but rather better: yet we see that a piece of money of gold soundeth far more flat than a piece of money of silver.

223. THE harp hath the concave not along the strings, but across the strings; and no instrument hath the sound so melting and prolonged, as the Irish harp. So as I suppose, that if a virginal were made with a double concave, the one all the length, as the virginal hath; the other at the end of the strings, as the harp hath; it must needs make the sound perfecter, and not so shallow and jarring. You may try it without any sound-board along, but only harp-wise at one end of the strings; or lastly, with a double concave, at each end of the strings one.

Experiments in consort touching the mixture of sounds.

But if

224. THERE is an apparent diversity between the species visible and audible in this, that the visible doth not mingle in the medium, but the audible doth. For if we look abroad, we see heaven, a number of stars, trees, hills, men, beasts, at once. And the species of the one doth not confound the other. so many sounds came from several parts, one of them would utterly confound the other. So we see, that voices or consorts of music do make an harmony by mixture, which colours do not. It is true nevertheless that a great light drowneth a smaller, that it cannot be seen; as the sun that of a glow-worm; as well as a great sound drowneth a lesser. And I suppose likewise, that if there were two lanthorns of glass, the one a crimson, and the other an azure, and a candle within either of them, those coloured lights would mingle, and cast upon a white paper a purple colour. And even in colours, they yield a faint and weak mixture: for white walls make rooms more lightsome than black, etc. but the cause of the confusion in sounds, and the inconfusion in species visible, is, for that the sight worketh in right lines, and maketh several cones; and so there can be no coincidence in the eye or visual point: but sounds, that move in oblique and arcuate lines, must needs encounter and disturb the one the other.

225. THE Sweetest and best harmony is, when

every part or instrument is not heard by itself, but a conflation of them all; which requireth to stand some distance off, even as it is in the mixture of perfumes; or the taking of the smells of several flowers in the air. 226. THE disposition of the air in other qualities, except it be joined with sound, hath no great operation upon sounds: for whether the air be lightsome or dark, hot or cold, quiet or stirring, except it be with noise, sweet-smelling, or stinking, or the like; it importeth not much; some petty alteration or difference it may make.

227. BUT sounds do disturb and alter the one the other: sometimes the one drowning the other, and making it not heard; sometimes the one jarring and discording with the other, and making a confusion; sometimes the one mingling and compounding with the other, and making an harmony.

228. Two voices of like loudness will not be heard twice as far as one of them alone; and two candles of like light, will not make things seen twice as far off as one. The cause is profound; but it seemeth that the impressions from the objects of the senses do mingle respectively, every one with his kind; but not in proportion, as is before demonstrated: and the reason may be, because the first impression, which is from privative to active, as from silence to noise, or from darkness to light, is a greater degree than from less noise to more noise, or from less light to more light. And the reason of that again may be, for that the air, after it hath received a charge, doth not receive a surcharge, or greater charge, with like appetite as it doth the first charge. As for the increase of virtue, generally, what proportion it beareth to the increase of the matter, it is a large field, and to be handled by itself.

Experiments in consort touching melioration of sounds.

229. ALL reflections concurrent do make sounds greater; but if the body that createth either the original sound, or the reflection, be clean and smooth, it maketh them sweeter. Trial may be made of a lute