RHUMB

RHUMB. A circle on the earth's surface making a given angle with the meridian of the place, marking the direction of any object through which it pa es. The divisions on the compa card are called rhumbs. See Mercat or's Chart. RHUMB LINE. In Naval Affairs, the track of a ship which cuts all the meridians at the same angle; called also the loxodromic curve. This being the simplest curve, is the route universally pursued; but a ship sailing on this curve never looks direct for her port until it comes in sight. See Loxodromic Curve. RHYME. {Gt. f)uf)fji,o;, measure; or Germ. re\m.) In Poetry, the correspondence of sounds in the last words or syllables of verses. The latter is the true rhyme of modern European languages. There are rhymed verses in the Latin cla ical poets, where the jingle seems intentional, and more distinct examples of it in the fragments of Roman military songs, ., which have comedown to us. But in the earlier period of the decay of the Latin language, when accent was substituted for metre in the rhythmical arrangement of the verse, rhyme made its way into the composition of church hymns, . It has been attempted, but with little succe , to deduce tliis innovation from the Goths, and from the Arabians; but the former, like the old Teutonic races, probably used alliteration, but no rhyme in their verses; and tlie latter could not liave influenced European literature until a period long after that in which rhyme first appears. A rhyme in which the final syllables only agree {slrain, complain), is called a male rhyme; one in which the two final syllables of each verse agree, the last being short {motion, ocean), female; and the latter is sometimes extended in Italian poetry to three syllables {fetnore, immemore), when the verse is called sdrucciolo. In English such a licence is hardly permi ible, except in burlesque poetry (see Hudibras and Don Juan for instances). By the strict rules of French prosody, the male and female species of rhymes must be alternately used, however intricate the disposition of the verse may be; although the last short syllable is generally mute, or very slightly sounded. Rhymes which extend not only beyond the three last syllables, but through the whole structure of the lines, are used in Arabian and Persian poetry. Rhymes in which the consonants of the last syllable in each verse are identical (dre , addre ) are vicious in English, but rather admired in French poetry. One more singularity of English poetry deserves notice: while from the irregularity of our spelling many syllables rhyme with each other, although widely di imilar in orthography (woo, pursue), there are, on the other hand, rhymes which speak to the eye, and not to the ear; i. e. in which the orthography of the rhyming syllables is the same, but the pronunciation different; as, wind, find; gone, alone. In the following triplet of Dryden, — 'Tis notliing yet; then poor and naked come. Thy Father will receive his unthrift home. And thy blest Saviour's blood discharKe the mighty sum, — it will be seen that the first and third lines rhyme in a legitimate manner, although the last syllables are differently spelt; while the first and second rhyme to the eye only, and not to the ear. This is a licence only rendered admi ible by precet'ent. RHYNCHOPHORES, Rhyncophora. (Gr. ^vy^cs, a beak, and (fi^a>, I carry.) The name of a family of Coleopterous insects, comprehending those which have the head prolonged in the form of a snout or proboscis. RHYTHM. (Gr.^vQfjuii.) The consonance of measure and time in poetry, prose composition, and music, and by analogy in dancing. Each verse or each period may be considered as a whole, within which the poetical rhythm is regular and exact, within certain limited variations, the rhetorical le perfect, and the pleasure derived from it rather matter of taste and experience than of rule. Those parts which receive the ictus or stre of the rhythm are termed arsis (elevation), the remainder form the thesis (depre ion); the former is frequently denoted to the eye by the accent marked ', when in a foreign or unknown word we wish to direct the voice in pronunciation to employ the correct emphasis. The smallest rhythmical division is the foot, by which every union of arsis and thesis is understood. A short syllable is an original unit of time; a long syllable contains two units. The number of feet enumerated in cla ical writers on metre amount to twenty-eight, including all the varieties which maybe formed out of two, three, or four syllables, long and short, and varying from two to eight units of time. See Foot, Metre. RIAL. A gold coin current in the reigns of Henry VI. and Elizabeth: under the former its value was 10s., under the latter 15s. RIBS. In Architecture, curviform timbers to which, in an arched or coved plaster ceiling, the laths are nailed. Ribs. A term for the timbers of a ship wliich spring from the keel, as the ribs of an animal from the back bone. HiBs. In Anatomy, the lateral appendages of a verte1053 RIGHT ASCENSION. bra, especially when developed so as to encompa the trunk. In the human subject there are twelve ribs. RICE. See Okyza. RICE PAPER. This substance is said to be a membrane of the Artocarpus incisa, or bread-fruit tree. (See AiiTOCARPEiE.) It is brought from China in small pieces, dyed of various colours, and is used as a materia) for painting upon, and for the manufacture of several fancy and ornamental articles. It is sometimes erroneously stated to be prepared from rice. (See Brewster, Edinb. Journ. of Science, vol.ii.) RICI'NIC ACID, One of the products obtained by distilling castor oil at a high temperature. RICKETS. Se^ Rachitis. RICOCHE'T FIRING, in Gunnery, is a mode of firing with small charges from pieces of ordnance elevated at small angles, as from 3° to 6°. It is a very destructive method; as the rebound causes the shot or shell to pa along a great space almost upon the ground, destroying all that it meets with in its way. The word signifies, literally, the sort of motion which is familiarly called ducks-and-drakes. as applied to a flat stone thrown on the surface of the water under a very small angle. RIDEAU. In Fortification, a small elevation of earth extending itself lengthwise on a plain, serving to cover a camp from the approach of the enemy, or to give other advantage to a post. Rl'DER. A term used to signify any addition to manuscripts or other documents, inserted after their completion. R IDGE. In Architecture, the upper horizontal timber in a roof, against which the rafters pitch. RIDING. The three divisions of the county of York are so termed, by a corruption of the Saxon word trilhing or triding (third part). RIDO'TTO. (Ital.) A favourite public Italian entertainment, consisting of nmsic and dancing; held generally on fast eves. RI'FLE GUNS. Muskets or pieces of ordnance, whose barrels, instead of being a clear cylinder inside, are furrowed with spiral channels. The object is to give the ball a rotatory motion about an axis, in consequence of which it preserves its direction with much greater certainty than when fired from the common clear barrel. See Gun. A body of men armed with rifles are called riflemen; but the term is most frequently applied to the military corps called the rifle brigade, and to the 60th regiment of the British army, which is dre ed in green and armed with rifles. RIG. The peculiar manner of fitting the masts and rigging to the hull of any ve el; thus schooner rig, ship rig, ., imply the masts and sails of these ve els without regard to the hull. RI'GGING. The system of cordage by which the masts are supported, and the sails extended or taken in. Tlie rigging is hence divided into standing rigging and running rigging. The standing rigging consists of the pendants, short strong ropes first put over the lower mast heads, and having thimbles for hooking tackles to; the shrouds, stays, and backstays. The lower rigging implies that of the lower masts, the topmast rigging that of the topmast, and so on. The size, strength, number of ropes, . of the rigging, are all matters determined by experience. A complete description of rigging is to be" found in the well-known work of Darcy Lever. RI'GGING LOFT. The room or rooms in which the rigging is prepared. RIGHT. In Geometry, a term sometimes used synonymously with straight, as right line; but generally as opposed to oblique. Thus, a right angle, the angle formed by two straight lines perpendicular to each other, or an angle of 90'^; right cone, cylinder, prism, pyramid, ., figures whose sides are perpendicular to the plane of the base. Right-angled Triangle. A triangle having one right angle. Right-angled Triangle. In Numbers. A favourite speculation of the Platonic school of mathematicians was to find rational numbers which should designate the sides of a ri^ht-angled triangle. Pythagoras gave the formula a and n'^+l, „, where n is odd. Plato gave 2n, 2 ' 2 ' tc2_i, andn^^. 1, where n is either odd or even. Various other forms have been given by subsequent writers. The determination of such sets of formulee forms a branch of the Diophantine Analysis, RIGHT SPHERE. In Geography, the position of the sphere when the equator cuts the horizon at right angles. RIGHT ASCENSION, in Astronomy, is the angle at the pole of the equator formed by two great circles, one of which pa es through the first point of Aries, and the other through a celestial body, and is consequently measured by the arc of the equator intercepted between those circles. Right ascension and declination are the Page 1067