DOORWAY. 394 DOPPLEBS PRINCIPLE. tanco, owinj; to the decadenec in omauicntal sculpture uiiJ detail. KoMANEsgiE IXkjrways. Hut the Koman- es<iui' art of the eU-M'iith eeiitury di'veliiped un entirely new ty|)e of doorway, whiili passed with niudilieatioMS into liothic art, and even inlliieneed the Henaissanee. It was the reeessiKl doorway, carved oflener with ligiired than with nien-ly deco- rative sculpture. The new use of stone vaultinj; in platv of wooden roofs in arehite»'ture necessitated the replacing of the old thin walls by very heavy thirk masonry, and the desire to give artistic form to the openings cut in these masses taxed the inventiveness of Romane-apie artists, anil led to the new style of |)ortaled doorways. The French schools of the Centre and South were especially prominent. The great portals of Saint Gilles and Saint Trophinie at Aries, in Provence, are masterpieces of composition, combining life- size figures, reliefs, and architectural framework in a manner suggesting old Roman triumphal arches. The portals of lloissac, Vezelay, and Autun, in Burgundy, are hardly inferior. The entire fa<.ade of these and similar churches was composed in connection with the doorways, which became its princii>al feature. They were usually in a group of three, the central doorway, leading into the nave, being usually higher and deeper. In both these schools the human figure formed the main part of the decoration, but in other schools of central France a system of floral and geometrical ornamentation was largely substi- tuted. The different planes in the sticcessive re- cesses were marked usually by small columns, sometimes with i)lain. sometimes with highly dec- orated shafts, and above them rose corresponding rows of archivolts. Gothic Doorw.ws. XATien the lie de France took the lead in the middle of the twelfth cen- tury, its architects developed the pointed portal, singly or in groups of three, with severer and even more thoroughly architectural sculpture, as in the old cathedrals of Chartres, Bourges, and Le Mans, and the Abbey of Saint-DOnis. Out of these sprang the unparalleled Gothic doorways of cathedral architecture, of which the masterpieces, in the thirteenth ccnturj-, are at Xotre Dame (Paris), Amiens, IJheims, and Chartres. The portals now project from thinner walls instead of being cut in the thickness of the walls, and, in- stead of being rather a structural necessity, are an artistic conception. The older style of molded archivolts is replaced by lines of figures, usiially under canopies, following the same curved lines, and making it possible to have several hundred figures in each doorway. The larger part of the cncyclopanlic thought of the scholastic Middle Ages, its conception of the theory and history of the universe, is expressed in the sculptures o{ these cathedral doorways, which thus acfjuire an unequaled iniport-nncc in the history of art. Only seldom is their importance e<|ualcd outside of France. In Italy there are a few fine examples in the north (Verona, San Donnino) and centre (Lucca, Perugia. Orvieto), but it is in the south- ern region of Apulia that the most beautiful Italian examples occur, especially at Bitonto, Bitetto, Altaniura, and their neighborhood, dat- ing from the thirteenth century. After earlier essays nt Bamberg and Freiberg, Germany more closely approaches the French style, which it evidently copied during the Gothic period. The portals of Strassburg are e<iual to the most brilliant French work (es|>ecially the portal of the Wise and Foidish irgins) ; those- of Frei- berg and Nurcml)erg are not much inferior, but the sculj)turc was usually neither as systematic nor as generally employed. Kven more decidedly French imitations are found in .S|>ain, for example in the portals of Burgos Cathedral. Knglish art of the Xorniau and (iotliic ]>eriods was far less successful: its doorways were usually insignifi- cant, with but little sculpture and poorly com- po.sed with the facade. Hkx.iss.vni.k 1")<>obvays. The Renaissance rcliiiied to a more classic simplicity in doorways, giving less prominence to them in facades and shearing them of sculpture, except occasionally the surface ornamentation of neoclassic pilaster- jamb and lintel, usually in the Anilx-sque style, made popular by Raphael and (Jiovanni da Udine in painting, and by their predecessors of the Tus- can and Lombard schools in scul|)ture. Some of the portals in Venice (e.g. San Zaccaria), in Florence (Uiiomo), and at the Cerlo^a of Pavia represent the early stage of the Kenaissani'C be- fore sculpture was tabooed, but later the purist Renaissance of the sixteenth century and the Barocco of that and the following century, dis- carded sculpture more rigorously, even in reli- gious work. The arch was used more fre<piently than the lintel, bossed work becoming more and more popular. The recess idea had been discard- ed at the beginning of the Renaiss.-ince. The doorway has never since regained its medi.Tval importance. BiDi.iOGR.PiiY. Illustrations and descriptions of portals are scattered through the histories of architecture and systematic collections of plates and photographs. For Apulian portals, consult Moscione's Collection of Photos: for French, the Robert Milusement Collection of Government Photos. The examples in southern Franw are given in Revoil. J.'architeclurr romane dii midi dc la France (Paris, 1864) : and other French ex- amples are given tmder "Porte" and "Portnil," in VioUet-le-Duc's Diet ionmi ire r<iisoiinc de I'arelii- lecture frnncaiic (Paris, I8.i8-fi8). DOPTPLEK, CuRiSTiAX ( 1 8n,'?-,53 ) . An .us- (rian physicist and mathematician, born in Salz- burg (crownland of that name). He studied at the Poh-technical Institute of Vienna, and be- came an instructor in mathematics there. Sub- sequently he held various academic appointments, including those of professor of clementari' mathe- matics and practical geometry in the Technical Institute at Prague (1841-47). professor of prac- tical geometry in the Polyteclinikum of Vienna (1848-51), and director of the physical institute of Vienna University (IS.'il-o.T) . He is Ix-st known as the first to enunciate the well-known I)<ippler's principle (q.v. ) (in his monograph I'elicr d(s fnrhiiie I.icht der Duppehterne. 1842). His further works include eriiuch einer sysle- mntischen Klnssi/ikntion der Farhen (1848). DOPPLEB'S PRINCIPLE. A law in phys- ics enuniiati>d by Christian Ooppler. an Austrian physicist, in 1S4'2. If a body which is emitting waves of any kind recedes from the instniment which is receiving the waves, the wave-numl>er is apparently decreased: and conversely, if the vi- brating body approaches the receiving instru- ment, the wave-nunil>er is increased. .Similar statements can be made, in pCTiernl, of the effect
