Page images
PDF
EPUB
[graphic]

it at an 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, through out, 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 con founded, 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 the air with it; the sharper and quicker 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.

[graphic]

Experiments in consort touching equality and inequality of sounds.

WE have spoken before, in the inquisition touch ing 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 them. selves, 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 weasand 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.

172. WATERS, in the noise they make as they run, represent to the ear a trembling noise; and in regals, where they have a pipe they call the nightingale-pipe, which containeth water, the sound hath a continual trembling and children have also little things they call cocks, which have water in them; and when they blow or whistle in them, they yield a trembling noise; which trembling of water hath an affinity with the letter L. All which inequalities of trepidation are rather pleasant than otherwise.

173. ALL base notes, or very treble notes, give an asper sound; for that the base striketh more air, than it can well strike equally: and the treble cutteth the air so sharp, as it returneth too swift to make the sound equal: and therefore a mean or tenor is the sweetest part.

174. We know nothing that can at pleasure make a musical or immusical sound by voluntary motion, but the voice of man and birds. The cause is, no

doubt, in the weasand or wind-pipe, which we call aspera arteria, which being well extended, gathereth equality; as a bladder that is wrinkled, if it be extended, becometh smooth. The extension is always more in tones than in speech: therefore the inward voice or whisper can never give a tone. And in singing, there is, manifestly, a greater working and labour of the throat, than in speaking; as appeareth in the thrusting out or drawing in of the chin, when we sing.

175. THE humming of bees is an unequal buzzing, and is conceived by some of the ancients not to come forth at their mouth, but to be an inward sound; but, it may be, it is neither; but from the motion of their wings for it is not heard but when they stir.

176. ALL metals quenched in water give a sibilation or hissing sound, which hath an affinity with the letter Z, notwithstanding the sound be created between the water or vapour, and the air. Seething also, if there be but small store of water in a vessel, giveth a hissing sound; but boiling in a full vessel giveth a bubbling sound, drawing somewhat near to the cocks used by children.

[graphic]

177. TRIAL would be made, whether the inequality or interchange of the medium will not produce an inequality of sound; as if three bells were made one within another, and air betwixt each; and then the outermost bell were chimed with a hammer, how the sound would differ from a simple bell. So likewise take a plate of brass, and a plank of wood, and join them close together, and knock upon one of them, and see if they do not give an unequal sound. So make two or three partitions of wood in a hogshead, with holes or knots in them; and mark the difference of their sound from the sound of an hogshead without such partitions.

Experiments in consort touching the more treble, and the more base tones, or musical sounds.

178. It is evident, that the percussion of the greater quantity of air causeth the baser sound; and the less quantity the more treble sound. The percussion of the greater quantity of air is produced by the greatness of the body percussing; by the latitude of the concave by which the sound passeth; and by the longitude of the same concave. Therefore we see that a base string is greater than a treble; a base pipe hath a greater bore than a treble; and in pipes, and the like, the lower the note-holes be, and the further off from the mouth of the pipe, the more base sound they yield; and the nearer the mouth, the more treble. Nay more, if you strike an entire body, as an andiron of brass, at the top, it maketh a more treble sound; and at the bottom a baser.

179. It is also evident, that the sharper or quicker percussion of air causeth the more treble sound; and the slower or heavier, the more base sound. So we see in strings; the more they are wound up and strained, and thereby give a more quick start-back, the more treble is the sound; and the slacker they are, or less wound up, the baser is the sound. And therefore a bigger string more strained, and a lesser string less strained, may fall into the same tone.

180. CHILDREN, women, eunuchs, have more small

[graphic]
« PreviousContinue »