Imágenes de páginas
PDF
EPUB

or rattle.

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 though 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

And so doth the aëtites 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 upward, 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 head above 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 saith, 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 nymphs 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 name aloud, that all the shore rang of it; and that Hylas from within the water answered his master, but, that which is to the present purpose, with so small and exile a voice, as Hercules thought he had been three miles off, when the fountain, indeed, was

fast by.

136. 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 the water, and from the part above. But when the saucer is wholly under the 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 the tablemen. i 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 bason; 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 scowereth 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

[ocr errors]

it at a 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.

162. A BELLOws blown in at the hole of a drum, and the drum then strucken, maketh the sound a little flatter, but no other apparent alteration. The cause is manifest; partly for that it hindereth the issue of the sound; and partly for that it maketh the air, being blown together, less moveable. Experiments in consort touching the loudness or

softness of sounds, and their carriage at longer or shorter distance.

163. The loudness and softness of sounds is a thing distinct from the magnitude and exility of sounds; for a base string, though softly strucken, giveth the greater sound; but a treble string, if hard strucken, will be heard much farther off. And the cause is, for that the base string striketh more air, and the treble less air, but with a sharper percussion.

164. It is therefore the strength of the percussion, that is a principal cause of the loudness or softness of sounds; as in knocking harder or softer; winding of a horn stronger or weaker; ringing of a hand-bell harder or softer, etc. And the strength of this percussion consisteth as much or more in the hardness of the body percussed, as in the force of the body percussing: for if you strike against a cloth, it will give a less sound; if against wood, a greater; if against metal, yet a greater; and in metals, if you strike against gold, which is the more pliant, it giveth the flatter sound; if against silver or brass, the more ringing sound. As for air, where it is strongly pent, it matcheth a hard body. And therefore we see in discharging of a piece, what a great noise it maketh.

We see also, that the charge with bullet, or with paper wet and hard stopped, or with powder alone rammed in hard, maketh no great difference in the loudness of the report.

165. The sharpness or quickness of the percussion, is a great cause of the loudness, as well as the strength ; as in a whip or wand, if you strike it, the louder sound it giveth. And in playing upon the lute or virginals, the quick stroke or touch is a great life to the sound. The cause is, for that the quick striking cutteth the air speedily; whereas the soft striking doth rather beat than cut.

Experiments in consort touching the communication

of sounds. The communication of sounds, as in bellies of lutes, empty vessels, etc. hath been touched obiter in the majoration of sounds; but it is fit also to make a title of it apart.

166. The experiment for greatest demonstration of communication of sounds, is the chiming of bells; where if you strike with a hammer upon the upper part, and then upon the midst, and then upon the lower, you shall find the sound to be more treble and more base, according unto the concave on the inside, though the percussion be only on the outside.

167. When the sound is created between the blast of the mouth and the air of the pipe, it hath nevertheless some communication with the matter of the sides of the pipe, and the spirits in them contained; for in a pipe, or trumpet, of wood, and brass, the sound will be diverse; so if the pipe be covered with cloth or silk, it will give a diverse sound from that it would do of itself; so if the pipe be a little wet on the inside, it will make a differing sound from the same pipe dry.

168. THAT sound made within water doth communicate better with a hard body through water, than made in air it doth with air, vide experimentum 134.

Experiments in consort touching equality and

inequality of sounds. We have spoken before, in the inquisition touching music, of musical sounds, whereunto there

may be a concord or discord in two parts; which sounds we call tones: and likewise of immusical sounds; and have given the cause, that the tone proceedeth of equality, and the other of inequality. And we have also expressed there, what are the equal bodies that give tones, and what are the unequal that give none. But now we shall speak of such inequality of sounds, as proceedeth not from the nature of the bodies themselves, but as accidental; either from the roughness or obliquity of the passage, or from the doubling of the percutient, or from the trepidation of the motion.

169. A bell, if it have a rift in it, whereby the sound hath not a clear passage, giveth a hoarse and jarring sound ; so the voice of man, when by cold taken the weașand groweth rugged, and, as we call it, furred, becometh hoarse. And in these two instances the sounds are ingrate, because they are merely unequal: but if they be unequal in equality, then the sound is grateful, but purling.

170. All instruments that have either returns, as trumpets; or flexions, as cornets; or are drawn up, and put from, as sackbuts; have a purling sound: but the recorder, or flute, that have none of these inequalities, give a clear sound. Nevertheless, the recorder itself, or pipe, moistened a little in the inside, soundeth more solemnly, and with a little purling or hissing. Again, a wreathed string, such as are in the base strings of bandoras, giveth also a purling sound.

171. But a lute-string, if it be merely unequal in its parts, giveth a harsh and untuneable sound; which strings we call false, being bigger in one place than in another; and therefore wire strings are never false. We see also, that when we try a false lute-string, we use to extend it hard between the fingers, and to fillip it; and if it giveth a double species, it is true; but if it giveth a treble, or more, it is false.

« AnteriorContinuar »