between a falconet and a base. See the article CANNON. RABBINISTS, among the modern Jews, an appellation given to the doctrine of the rabbins concerning traditions, in oppofition to the caraites, who reject all traditions. See the article CARAITES. RABBIT, cuniculus, in zoology, a well known animal of the lepus, or harekind, with a very short tail, The rabbit, though a smaller, is a handfomer creature than the hare, but is of various colours even in the fame country, its general one in this kingdom being a pale brownish-grey on the back, and white on the belly; however, there are fome darker, of a filvery-grey, and altogether white. There is alfo a long-tailed fpecies, of the fize of our common rabbit, called the fiberian rabbit, from its being frequent in Ruffia and Tartary. For the method of catching rabbits, by means of ferrets, fee FERRET. RACCOURCY, in heraldry, fignifies the fame as coupee; that is, cut off or shortened; and denotes a crofs, or other ordinary, that does not extend to the edge of the efcutcheon, as they always do when abfolutely named without fuch diftinction. RACE, in general, fignifies running with others in order to obtain a prize, either on foot, or by riding on horse-back, in chariots, &c. Racing was one of the exercises among the antient grecian games, which was performed in a course containing an hundred and twenty five paces; and those who contended in these foot-races were frequently clothed in armour. Chariot and horse races also made a part of thefe antient games. See GAMES. For horse-racing, as practifed amongst us, fee the article HORSE RACING, RACE, in genealogy, a lineage or extraction continued from father to fon. RACHITIS, the RICKETS, in medicine. See the article RICKETS. RACILLA, one of the leaft of the islands of the Archipelago, near the island of Aio, not inhabited, RACK, in the manege, a pace in which a horse neither trots nor ambles, but shuffles as it were between, The racking-pace is indeed much the fame as the amble, only it is a swifter time and shorter tread. RACK is also a wodden frame, made to hold hay or fodder for catele. 9 RACK, an engine of torture, furnished Rack is also a fpirituous liquor which Goa and Batavia are the chief places for Rack, on being imported, pays a duty To RACK wines, &c. to draw them off from Hence rack-vintage is frequently used RACK RACKELSBURG, a town of Germany, in the circle of Auftria, twenty-three miles fouth east of Gratz. RACKET, a kind of bat to ftrike the ball with at tennis; usually confifting of a lattice or net-work of cat-gut ftrained very tight in a circle of wood, with a shaft or handle. RACKET is alfo a kind of fnow shoe, or machine, which the favages of Canada bind to their feet, to enable them to walk more commodiously on the fnow; made much in the manner of a tennis-racket. Its figure is a lozenge, of which the two obtufe angles are turned off. It is bound about with very fine thongs of leather, the mashes of which are much smaller and clofer than those of our rackets. In the middle is fitted a kind of fhoe lined with wool or hair, to be tied on to the ancle. RACKOON, coati, in zoology, an american quadruped of the fhape of a beaver, only fomewhat fmaller, and with hair like that of a fox; its head too is like that of a fox, only that the ears are fhorter, roundish, and naked; its tail is longer than its body, and not unlike that of a cat, with annular ftreaks of different colours. RADIÆA, in anatomy, a branch of the brachial artery. See ARTERY. RADIÆUS, or RADIALIS. See the article RADIALIS. RADIAL CURVES, are curves of the fpiral kind, whofe ordinates, if they may be fo called, all terminate in the center of the including circle, appearing like radii of that circle, whence the name. See the articles CURVE and SPIRAL. RADIALIS, or RADIEUS, in anatomy, the name of two mufcles of the arm; one of which, called radialis internus, is one of the three flexor muscles of the carpus, or hand, which arising from the internal condyle of the humerus, is inferted into the bone of the carpus next the thumb; and the other, called radialis externus, is one of the three extenfor muscles of the hand, which arifing from the external condyle of the humerus, is inferted into the first metacarpal bone. See FLEXOR and EXTENSOR. RADIANT, or RADIATING POINT, in optics, is any point of a vifible object from whence rays proceed. See the articles VISION and RADIATION. RADIANT, or RAYONANT, in heraldry. See the article RAYONANT. RADIATED FLOWERS, in botany, are fuch as have feveral femi-flofcules fet round a difk, in form of a radiant ftar: those which have no fuch rays are called discous flowers. See the articles FLOWER, BOTANY, &c. The term radiated is also used with refpect to one of the antient crowns. See the article CROWN. RADIATION, the act of a body emitting or diffufing rays of light all round, as from a center. See the articles LIGHT, RAY, &c. Radiation is confidered in optics as threefold, viz. dire&t, reflected, or refracted. See the articles VISION, REFLECTION, and REFRACTION. Though every vifible body be radiating, Hence phyficians talk much of a radical Algebraifts also speak of the radical fign fhoot out roots. See the articles Root and VEGETATION. RADICLE, that part of the feeds of all plants, which upon vegetating becomes RADISH, raphanus, in botany, &c. See In trigonometry, the radius is termed For For the radius of the evolute, of curvature, &c. in the higher geometry, see EVOLUTE, CURVATURE, &c. Some also call the fore staff radius aftronomicus. See FORE-STAFF. RADIUS, in anatomy, the exterior bone of the arm, defcending along with the ulna from the elbow to the wrift. See the article SKELETON. In its upper extremity there is a glenoid cavity for its articulation with the humerus; alfo a creft, by means of which it is articulated with the ulna: in the lower extremity the head is thicker, and of a more angular figure, with a very large hollow in its middle, for its articulation with the wrift. RADIX, the fame with root. See the article RooT. RADNOR, the capital of the county of Radnor in Wales, fituated in weft long. 3o 6', north lat. 52° 20′. RAFFLING, a game with three dice, in which he who throws the greatest pair, or pair royal, in three cafts, wins the prize or stake. The raffle is properly a doublet or triplet; for a raffle of all aces or duces, carries it against mere points. Raffling is also used when a number of people club for the purchase of a commodity; and he that throws the higheft on three dice takes it. RAFTERS, in building, are pieces of timber, which standing by pairs on the reason or raifing piece, meet in an angle at the top, and form the roof of a building. It is a rule in building that no rafters fhould ftand farther than twelve inches from one another: and as to their fizes or fcantlings, it is provided by act of parliament, that principal rafters, from twelve feet fix inches to fourteen feet fix inches long, be five inches broad at the top and eight at the bottom, and fix inches thick. Thofe from fourteen feet fix inches to eighteen feet fix inches long, to be nine inches broad at the foot, feven inches at the top, and feven inches thick: and those from eighteen feet fix inches, to twenty-one feet fix inches long, to be ten inches broad at the foot, eight at the top, and eight thick. Single rafters, eight feet in length, muft have four inches and a half, and three inches three quarters in their fquare. Those of nine feet long must be five and four inches fquare. Principal rafters fhould be nearly as thick at the bottom as the beam, and fhould diminish in their length one fifth or one fixth of their breadth; the kingposts should be as thick as the principal rafters, and their breadth, according to the bigness of them that are intended to be let into them, the middle part being left fomewhat broader than the thicknefs. RAG, or RAKE, a company, or herd of young colts. RAGGED-HAWK, among falconers, is one that has his feathers broken. See the article HAWK. RAGGED, in heraldry. See RAGULED. RAGOUT, or RAGOO, a fauce, or feafoning, intended to roufe the appetite when loft or languishing. This term is also used for any high feasoned dish prepared of flesh, fish, greens, or the like; by ftewing them with bacon, falt, pepper, cloves, and the like ingredients. We have ragouts of celery, of endive, afparagus, cock's-combs, giblets, cray-fish, &c. The antients had a ragout called garum, made of the putrified guts of a certain fifh kept till it diffolved into a mere fanies, which was thought fuch a dainty, that, according to Pliny, its price equalled that of the richest perfumes. RAGULED, or RAGGED, in heraldry, jagged or knotted. This term is applied to a crofs formed of the trunks of two trees without their branches, of which they fhew only the ftumps. See plate CCXXVII. fig. 2. Raguled differs from indented, in that the latter is regular, the former not. RAJA, the title of the indian black princes, the remains of those who ruled there before the moguls. Some of the rajas are faid to preferve their indepencdeny, efpecially in the mountainous parts; but most of them pay an annual tribute to the mogul. The indians call them rai; the Perfians raian, in the plural; and our travellers rajas, or ragias. RAJA, in ichthyology, a genus of the fire-flaire, fea-eagle, white-horfe, fkaite, and torpedo or cramp-fish. RAJAMAHAL, a city of the hither India, fituated on the river Ganges, in 86o 30' eaft long. and 24° 30′ north lat. RAJANIA, in botany, a genus of the dioecia hexandria clafs of plants, without any flower petals; the fruit is roundih, and contains a single feed of the fame thape. RAIL, in architecture, is used in different fenfes, as for those pieces of timber which lie horizontally between the pannels of wainfcot; for those which lie over and under the balufters in balconies, ftaircafes, and the like; and alfo for those pieces of timber which lie horizontally from poft to poft in fences, either with poles or without. RAIL, ortygometra, in ornithology, a genus of birds of the order of the fcolopaces, the beak of which is fhorter than the toes: it is of a compreffed form, and terminated in a point; but the two chaps are equal in length. It is of the fize of the common magpye, and is an elegant bird, of a bright brown colour, variegated with black fpots; it is common in rich paftures, where its conftant note is crex, crex. RAIN, a watery-meteor, which defcends from the clouds in form of drops of water. See CLOUD, METEOR, &c. Rain is apparently the precipitated vapours of watery clouds: thus, when various congeries of clouds are driven together by the agitation of the winds, they mix and run into one body, and by that means diffolve and condenfe each other into their former fubftance of water; alfo the coldness of the air is a great means to collect, compact, and condense clouds into water; which being heavier than the air, muft of neceffity fall through it in the form we call rain. Now the reason why it falls in drops, and not in whole quantities, as it becomes condensed, is the refiftance of the air; whereby, being broken and divided into fmaller and smaller parts, the farther it paffes through the air, it at last arrives to us in small drops. Mr. Derham accounts for the precipitation hence, that the veficulæ being full of air, when they meet with a colder air than that they contain, their air is contracted into a lefs fpace; and, confequently, the watery fhell rendered thicker, fo as to become heavier than the air, &c. Others only allow the cold a part in the action, and bring in the winds as fharers with it; indeed, it is plain, that a wind, blowing against a cloud, will drive its veficulæ upon one another, by which means feveral of them coalefcing, will be enabled to descend; and the effect will be still more confiderable if two oppofite winds blow towards the fame place. Add to this, that clouds already formed, happening to be aggravated by fresh acceffions of vapour continually afcending, may thence be enabled to defcend. According to Rohault, the great cause of rain is the heat of the air, which, after continuing for fome time near the earth, is at length carried up on high by a wind, and there thawing the fnowy villi, or flocks of the half frozen vesiculæ, reduces them into drops; which, coalefcing, defcend. Others, as Dr. Clarke, &c. afcribe this defcent of the clouds rather to an alteration of the atmosphere than of the veficulæ; and fuppofe it to arife from a diminution of the elastic force of the air. This elafticity, which depends chiefly or wholly on the terrene exhalations, being weakened, the atmosphere finks under its burden, and the clouds fall. Now the little veficles, being once upon the defcent, will perfift therein, notwithftanding the increase of resistance they every moment meet with. For as they all tend toward the center of the earth, the farther they fall, the more coalitions will they make; and the more coalitions, 'the more matter will there be under the fame furface; the forface only increasing as the fquares, but the folidity as the cubes; and the more matter under the fame furface, the less resistance there will be to the fame matter. Thus, if the cold, wind, &c. act early enough to precipitate the afcending veficles, before they are arrived at any confiderable height, the coalitions being but few, the drops will be proportionably small; and thus is formed a dew. If the vapours be more copious, and rife a little higher, we have a mift or fog. A little higher ftill, and they produce a fmall rain, &c. If they neither meet with cold nor wind, they form a heavy, thick, dark sky. Hence, many of the phænomena of the weather may be accounted for: as, why a cold fummer is always a wet one, and a warm, a dry one; Why we have com monly monly most rain about the equinoxes; Why a fettled, thick, close sky, fearce ever rains, till it have been first clear. As to the quantity of rain that falls, its proportion in feveral places at the fame time, and in the fame place at several times, we have ftore of obfervations, journals, &c. in the Memoirs of the French Academy, Philofophical Tranfactions, &c. Preternatural RAIN'S, as of blood, are very frequent in our annals, and even natural hiftories; yet, if enquired into, they will be found other things than rain. Those rains, Dr. Merret obferves, are nothing more than the excrements of infects, as butterflies, &c. And he adds, that it is very evident the rains of wheat are nothing but ivy-berries swallowed by the starling, and voided again by ftool. RAINS, in the fea-language, all that tract of fea to the northward of the equator, between four and ten degrees latitude, and lying between the meridian of Cape Verde and that of the eaftermoft islands of the fame name. It is fo called from the almost continual calms, conftant rains, thunder and lightning found there. RAIN-BOW, iris, in meteorology, a meteor, in form of a party coloured arch, or semi-circle, exhibited in a rainy fky, oppofite to the fun, by the refraction of his rays in the drops of falling rain. See the article REFRACTION. In order to illuftrate this phænomenon, fuppofe BNFG (pl. CCXXVI. fig. 1.) to be a spherical drop of falling rain, and AN a ray of the fun falling upon it in the point N; which ray fuppofe refracted to F, from thence reflected to G, and there again refracted in the direction GR to the eye of a spectator; and let IG be perpendicular to the drop in the point G; then will the ray or beam of light, by its refraction at G, be separated into feveral forts of rays, which will paint their respective colours in that part of the drop; of which that next the perpendicular IG will be red, as being leaft refracted; and the reft in order above it, viz. orange, yellow, green, blue, indigo, violet. Now it is found by computation, that the greatest angle SEO, (ibid. fig. 2.) or EOP, because OP parallel to SE, under which the moft refrangible rays can come to the eye of the fpectator at O, is 40° 17′; and that the great angle F OP, under which the most refrangible rays come to the eye at O, is 42° 2′: and so all the particles of water, within the difference of of thofe two angles, EF, will exhibit feverally the various colours of the prifm, and conftitute the interior rainbow in the cloud. See COLOUR. If the beam of light go not out of the drop, at G, but is reflected a fecond time, to H; (ibid. fig. 1 and 2.) and is there refracted in the direction HS, making the angle SY A with the incident ray AN, it will paint on the part H the feveral colours of light; but in an inverfe order to the former, and more faint, by reafon of the rays loft by the fecond reflection. It has been found also, that the least angle SGO, or GOP, under which the leaft refrangible rays can come to the eye at O, after two reflections and two refractions, is 50° 57′ i and the leaft angle HOP, under which the most refrangible rays can come to the eye in this cafe, is 54° 7': whence all the colours of the exterior rain-bow, will be formed in the drops from G to H; which is the breadth of this bow, viz. 3° 10'; whereas the breadth of the former, or interior bow, viz. E F, is but 1° 45′ i and the distance between the bows, viz. FG, is 8° 55'. And fuch would be the measure of the bows, were the fun but a point; but fince his body fubtends an angle of half a degree, it is evident, by fo much will each bow be increased, and their distance diminished. To apprehend rightly the different affections of the rain-bow, we must attend to the following particulars. 1. That though the rain-bow be occafioned by the refracted and reflected light of the fun falling on the drops of rain, yet neither of them is produced by any rays falling on any part of the drop indifferently, but by thofe only which fall on the furface of the drop BLOG (ibid. fig. 1, 2, 3.) in or about the point N, as the ray AN; those which fall nearer to B, or farther towards L, being unconcerned in this production. 2. The internal bow is produced by two refractions and one reflection. The firft refraction is of the incident rays extremely near AN, by which they proceed from N to one common point or focus at F, from whence they are reflected to G, and are there a fecond time refracted towards R, and produce the various colours of the faid bow. There is a neceffity that feveral rays 3. fhould |