Ra"di*o (?), a. Of or pertaining to, or employing, or operated by, radiant energy, specifically that of electric waves; hence, pertaining to, or employed in, radiotelegraphy.
Ra`di*o-ac"tive (?), a. [Radio- + active.] (Physics) Capable of luminescence under the action of cathode rays, X rays, or any of the allied forms of radiation. -- Ra`di*o-ac*tiv"i*ty, n.
Ra`di*o*con*duc"tor (?), n. (Elec.) A substance or device that has its conductivity altered in some way by electric waves, as a coherer.
Ra"di*o*graph (?), n. [Radio- + -graph.] 1. An instrument for measuring and recording solar radiation.
2. An image or picture produced upon a sensitive surface, as of a photographic plate, by some form of radiation other than light, as the Röntgen rays, radium rays, etc.; esp., a picture of opaque objects traversed by the rays; a skiagraph.
Ra"di*o*graph, v. t. To make a radiograph of. -- Ra`di*og"ra*pher (#), n.
Ra`di*og"ra*phy (?), n. Art or process of making radiographs. -- Ra`di*o*graph"ic (#), *graph"ic*al (#), a. -- Ra`di*o*graph"ic*al*ly, adv.
Ra`di*om"e*try (?), n. (Physics) The use of the radiometer, or the measurement of radiation. -- Ra`di*o*met"ric (#), a.
Ra"di*o*phare (?), n. [Radio- + phare.] A radiotelegraphic station serving solely for determining the position of ships. The radius of operation of such stations was restricted by the International Radiotelegraphic Convention (1912) to 30 nautical miles.
Ra`di*op"ti*con (?), n. [Radio- + stereopticon.] See Projector, above.
Ra`di*os"co*py (?), n. [Radio- + -scopy.] Direct observation of objects opaque to light by means of some other form of radiant energy, as the Röntgen rays. -- Ra`di*o*scop"ic (#), *scop"ic*al (#), a.
Ra`di*o*tel"e*gram (?), n. A message transmitted by radiotelegraph.
Ra`di*o*tel"e*graph (?), n. [Radio- + telegraph.] A wireless telegraph.
Ra`di*o*tel`e*graph"ic (?), a. Of or pertaining to radiotelegraphy; employing, or used or employed in, radiotelegraphy.
Ra`di*o*te*leg"ra*phy (?), n. [Radio- + telegraphy.] Telegraphy using the radiant energy of electrical (Hertzian) waves; wireless telegraphy; -- the term adopted for use by the Radiotelegraphic Convention of 1912.
Ra`di*o*tel"e*phone (?), n. A wireless telephone. -- Ra`di*o*te*leph"o*ny (#), n.
Ra`di*o*ther"a*py (?), n. [Radio- + therapy.] (Med.) Treatment of disease by means of Röntgen rays or other forms of radioactivity.
Ra`di*o*tho"ri*um (?), n. (Chem.) A radioactive substance apparently formed as a product from thorium.
Ra`di*um (?), n. [NL., fr. L. radius ray.] (Chem.) An intensely radioactive metallic element found (combined) in minute quantities in pitchblende, and various other uranium minerals. Symbol, Ra; atomic weight, 226.4. Radium was discovered by M. and Mme. Curie, of Paris, who in 1902 separated compounds of it by a tedious process from pitchblende. Its compounds color flames carmine and give a characteristic spectrum. It resembles barium chemically. Radium preparations are remarkable for maintaining themselves at a higher temperature than their surroundings, and for their radiations, which are of three kinds: alpha rays, beta rays, and gamma rays (see these terms). By reason of these rays they ionize gases, affect photographic plates, cause sores on the skin, and produce many other striking effects. Their degree of activity depends on the proportion of radium present, but not on its state of chemical combination or on external conditions.The radioactivity of radium is therefore an atomic property, and is explained as result from a disintegration of the atom. This breaking up occurs in at least seven stages; the successive main products have been studied and are called radium emanation or exradio, radium A, radium B, radium C, etc. (The emanation is a heavy gas, the later products are solids.) These products are regarded as unstable elements, each with an atomic weight a little lower than its predecessor. It is possible that lead is the stable end product. At the same time the light gas helium is formed; it probably consists of the expelled alpha particles. The heat effect mentioned above is ascribed to the impacts of these particles. Radium, in turn, is believed to be formed indirectly by an immeasurably slow disintegration of uranium.
Raf"fi*a palm (?). (a) A pinnate- leaved palm (Raphia ruffia) native of Madagascar, and of considerable economic importance on account of the strong fiber (raffia) obtained from its leafstalks. (b) The jupati palm.
Raf"fle (?), n. [See Raff, n. & v., and Raffle.] Refuse; rubbish; raff.
Rag, v. t. 1. (Music) To play or compose (a piece, melody, etc.) in syncopated time. [Colloq.]
2. To dance to ragtime music, esp. in some manner considered indecorous. [Colloq. or Slang]
{ Rag"na*rok" (?), ||Rag"na*rök" (?) }, n. [Icel., fr. regin, rögn, gods + rök reason, origin, history; confused with ragna- rökr the twilight of the gods.] (Norse Myth.) The so-called "Twilight of the Gods" (called in German Götterdämmerung), the final destruction of the world in the great conflict between the Æsir (gods) on the one hand, and on the other, the gaints and the powers of Hel under the leadership of Loki (who is escaped from bondage).
Rag"time`, n. (Mus.) Time characterized by syncopation, as in many negro melodies. [Colloq.]
Raif"fei`sen (?), a. (Economics) Designating, or pertaining to, a form of coöperative bank founded among the German agrarian population by Friedrich Wilhelm Raiffeisen (1818-88); as, Raiffeisen banks, the Raiffeisen system, etc. The banks are unlimited-liability institutions making small loans at a low rate of interest, for a designated purpose, to worthy members only.
Rail, n. A railroad as a means of transportation; as, to go by rail; a place not accesible by rail.
Rail"road`, v. t. To carry or send by railroad; usually fig., to send or put through at high speed or in great haste; to hurry or rush unduly; as, to railroad a bill through Condress. [Colloq., U. S.]
{ ||Ra`ki", ||Ra`kee" } (?), n. [Turk. rkarrack.] A kind of ardent spirits used in southern Europe and the East, distilled from grape juice, grain, etc.
||Ral"liés" (?), n. pl. [F., p. p. pl. See Rally, v. t.] A French political group, also known as the Constitutional Right from its position in the Chambers, mainly monarchists who rallied to the support of the Republic in obedience to the encyclical put forth by Pope Leo XIII. in Feb., 1892.
Ram"e*kin, n. = Ramequin.
Ram"e*quin (?), n. [F.] The porcelian or earthen mold in which ramequins are baked and served, by extension, any dish so used.
Ram"til (?), n. [Bengali ram- til.] A tropical African asteraceous shrub (Guizotia abyssinica) cultivated for its seeds (called ramtil, or niger, seeds) which yield a valuable oil used for food and as an illuminant.
||Ran`che*ri"a (?), n. [Sp. rancheria.] 1. A dwelling place of a ranchero.
2. A small settlement or collection of ranchos, or rude huts, esp. for Indians. [Sp. Amer. & Southern U. S.]