BEL 



BEL 



ties, to blow up the fire ; it serves also 

 for organs and other pneumatic instru- 

 ments, to give them a proper degree of 

 air. All these are of various construc- 

 tions, according to their different pur- 

 poses, but in general they are composed 

 of two flat boards, sometimes of an oval, 

 sometimes of a triangular figure. Two 

 or more hoops, bent according to the 

 figure of the boards, are placed between 

 them ; a piece of leather, broad in the 

 middle, and narrow at both ends, is nail- 

 ed on the edges of the boards, which it 

 thus unites together: as also on the 

 hoops which separate the boards, that 

 the leather may the easier open and fold 

 again ; a tube of iron, brass, or copper, is 

 fastened to the undermost board, and 

 there is a valve within that covers the 

 holes in the under board, to keep in the 

 air. 



The action and effect of bellows of eve- 

 ry kind, whether constructed of leather 

 or wood, wrought by men, by steam, or 

 by water, depends on this, that the air 

 which enters them, and which they con- 

 tain when raised, is again compressed in- 

 to a narrower space when they are clos- 

 ed. As the air flows to that place where 

 it meets with the least resistance, it must 

 of necessity fly out of the pipe with a ve- 

 locity proportional to the force by which 

 it is compressed, and must therefore blow 

 stronger or weaker, as the velocity with 

 which the top and bottom of the bellows 

 meet is greater or less. The blast will 

 last in proportion to the quantity of air 

 that was drawn into the bellows through 

 the valve. The action of the bellows 

 bears a near affinity to that of the lungs, 

 and what is called blowing in the latter 

 affords an illustration of what is called re- 

 spiring in the former : hence bellows 

 have been employed in restoring suspend- 

 ed animation. See DROWXING. 



The bellows of smiths, founders, &c. 

 are worked by means of a rocker, with a 

 string fastened to it, and pulled by the 

 workman. One of the boards is fixed so 

 as not to play at all. By drawing down 

 the handle of the rocker, the moveable 

 board rises, and by means of a weight on 

 the top of the upper board sinks again. 

 Large bellows used in founderies, &c. re- 

 ceive their motion from water wheels or 

 steam : others that are small are worked 

 by the feet of the men using them, as is 

 the case with enamellers, jewellers, &c. 

 The bellows of an organ are six feet long-, 

 and four feet broad, each having an aper- 

 ture of four inches, that the valve may 

 play easily. To blow an organ of sixteen 



feet, there are required four pair of these 

 bellows. 



BELLUJE, in natural history, the sixth 

 order of the class Mammalia. They are 

 distinguished by tore-teeth, obtuse ; feet 

 hoofed ; motion heavy ; food vegetables. 

 There are four genera, viz. 



Equus. Sus. 



Hippopotamus. Tapir. 



BELLY, in anatomy, the same with 

 what is more usually called abdomen, 

 or rather the cavity of the abdomen. See 

 ANATOMY. 



BELLY of an instrument, in music, is 

 that thin smooth board, over which the 

 strings in a harpsichord, piano-forte, Sec. 

 are distended, and which by the vibration 

 contributes to the tone. In a violin, and 

 other instruments performed with a bow, 

 and in a guitar, it is that part of the body 

 which lies immediately under the strings. 



BELT, in the military art, a leathern 

 girdle for sustaining the arms, &c. of a 

 soldier. 



BELTS, in astronomy, zones or girdles 

 surrounding the planet Jupiter, brighter 

 than the rest of his body, and terminated 

 by parallel lines. They are observed, 

 however, to be sometimes broader and 

 sometimes narrower, and not always oc- 

 cupying exactly the same part of the 

 disc. Jupiter's belts were first observed 

 and described by Huygens. Dark spots 

 have often been observed on the belts of 

 Jupiter; and M. Cassini observed a per- 

 manent one on the northern side of the 

 most southern belt, by which he deter- 

 mined the length of Jupiter's days, or the 

 time in which the planet revolves upon 

 its axis, which is 9 h 56m. Some astrono- 

 mers suppose that these belts are seas, 

 which alternately cover and leave bare 

 large tracts of the planet's surface : and 

 that the spots are gulphs in those seas, 

 which are sometimes dry, and sometimes 

 full. But Azout conceived that the spots 

 are protuberances of the belts ; and 

 others again are of opinion that the trans- 

 parent and moveable spots are the sha- 

 dows of Jupiter's satellites. 



Cassini also speaks of the belts of Sa- 

 turn being three dark, straight, parallel 

 bands, or fascix, on the disc of that pla- 

 ne^ But it does not appear that Saturn's 

 belts adhere to his body, as those of Ju- 

 .piter do ; but rather that they are large 

 dark rings surrounding the planet at a 

 distance. Some imagine that they are 

 clouds in the atmosphere of Saturn, 

 though it would seem that the middle- 

 most is the shadow of his ring. 

 BELTS, in geography, certain straits 



