MAP. 34 MAPLE. have taken the place of tlie beautiful copper-plate prints. The general scope of the -work of the United States Geological Survey is the surveying and mapping of the entire territory of the United States to obtain basic topographic maps for the exhibition of geological data, liach scpiarc de- gree, called a "rectangle," in which the cointry is divided, is surveyed and niap])cd separately. (See SrRVEYiN'G.) The detailed information thus ob- tained in the field survey is rovighly inked in at the close of the season, and then turned over to the photographer for reduction to the scale of publication. From the reduced photographic copies engravings are made on stone, each sheet requiring three separate stone engravings. From the engraved stones transfers are made to other stones and the sheets printed on a lithographic press. The map shown on the accompanying plate has been designed to illustrate the methods of delineation employed by the I'nited States Coast and Geodetic Survey and United States Geologi- cal Survey in the preparation of their charts and topographical maps. The map is. of course, ideal, and shows the use of the variois conven- tional signs. In the upper right-hand corner is a compass card indicating the true north and the magnetic variation of the particular locality, while the depths of the ocean are given in fath- oms. The shoals are indicated as alrcadj" ex- plained, and also the lighthouses, rocks, beacons, buoys, etc. The contour lines which form such a prominent feature of a topographical map connect all places at the same height above sea-level, and the interval between them is ."iO feet, darker lines being drawn at the intervals of 2'M feet. (See COXTOIRS.) In the topograidiical maps of the United States Government the contour interval is generally '20 feet, with heavier lines marking every 100 feet. In the maps of the Geological Survey these contour lines or relief figures are in brown to distinguish them from the drainage, which is in blue. Such cultural features as buildings, roads, trails, railroads, tunnels, ferries, and bridges all have their appropriate markings, which ,nre shown in the map. Kresh marshes are distin- guished from salt marshes by dilTcrent conven- tional signs, while wooded country is shown in the lower right-hand corner of the map. Triangu- lation stations are marked by a A and bench marks by an X. Mines and quarries, mine tun- nels and" shafts, also have their appropriate signs as indicated. Relief maps are usiially constructed after a eonVnur maj) has been prejiared by building up the surface of the country, tising eardboanl of uniform thickness to represent the sticcessive contour lines. When one such relief map has been constructed, copies are made either in plaster of Paris or papier machf. Maps of the Uxitkd States. The following is the list of the more important b>ireaus of the United States Government which publish maps for general distribution: United States Coast an<l (Jeodetic Survey. Washington — maps pertain- ing to the Atlantic and Pacific coasts of the United States, and those of Alaska, the West Indies, and the Philippines. I'nited States Gen- logical Survey. Washington — topographical maps, special monograph maps of mining districts, and maps relating to irrigation. General Land Olhce, Washington — township plats. State maps, maps of mineral and private land claims, enlarged maps of the United States. United States Hy- drographic OfKce, Navy Department. Washing- ton — hydrographic charts of domestic and foreign harbors, of coast lines, and pilot charts of the North Atlantic Ocean. Ollicc of the Survey of the tireat Lakes, Detroit, ^lich. — maps pertain- ing to the hydrography of the Great Lakes. Mis- sissippi River Commission, Saint Louis, Mo. — maps of the Mississippi River. Bibliography. Gretschel, Lehrhuch der Kai- tcn/jrojelction (Weimar, 187.3) ; Schott, "A Com- parison of the Relative Value of the Polyconic Projection," Report of Viiited Slates Coast and Geodetic Survey, Appendix 15 (Washington, 1880) ; Fiorini, Le projezioni deUe carte geoijra- fiche (Bologna, 1881) ; Tissot, Memoire sitr la ■representation des surfaces ct les projections dcs cartes geoyraphiques (Paris. 1881); Craig, "A Treatise on Projections," United States Coast and Geodetic Survey (Washington, 188"2) ; Stein- hauser, Grundzilge der mathematischcn Geogra- phic und JjandkartenprojeUtion (."Jd ed.. Vienna, 1887) ; Verner. Map Reading and FAementary Field Sketchinq (London. 1803): West, The, Flcincnfs of Military Topography (London, 1S!14) ; Woodward. Geographical Tables (Wash- ington, 1894) : Cehrian and Los Areos, Teoria general dc las proyecciones geogrdficas (Madrid, 1805) ; Gelcich and Sauter, Kartenlunde ge- schichtlich dargestellt (Stuttgart, 1807) : Zon- dervan, Allgemeine Kartenkunde (Leipzig, 1901). See Chart; Hydrography; Surveying. MAP, or MAPES, Walter. A mediaeval au- thor, of Welsh descent, born probaldy in Here- fordshire, England, about 1140. He studied in Paris soon after 1154; was connected with the household of Henry II., whom he attended abroad; was sent on missions to Paris (1173) and Rome (117IM ; and was precentor of Lincoln, incumbent of Westbury, Gloucestershire, canon of Saint Paul's, and .rchdeacon of Oxford (1107). He died about 1210. JIap's one undoubted work is De yugis Curialium (""The Triflings of Courtiers"), a curious and interesting medley of anecdotes, reminiscences, and stcuies, to which we owe most of our knowledge of Map's life. In several of the manuscripts of the prose Lancelot, (irail. and Morte d'Arthur his name occurs as the author. But recent scholarship places them at a later date. With some doulit the Golias poems are ascribed to him. satires in Latin on the clergy. Map was especially a foe of Jews and Cistercians. In this collection occurs the famous drinking song "Meum est proposifum in tabcrna niori," which was rendered into English by Leigh Hunt. Consiilt the Latin Poems Atlrihiilrd to Mail and De Xugis Curialium. ed. by Wright, Canulcn Society (London, 1841 and 1850). MAPLE (AS. mapol, tnapul, mcrpel. Icel. mopurr. OIIG. maxzaltra, mazzoltra, Ger. Mas- holder, maple), Acer. A genus of trees of the natural order Accracea", containing nearly 100 species, natives of north temperate regions. es]ip- eially abundant in North .merica and Eastern .•sin. They have opposite, lobed or palmate leaves without stipules; flowers in small axil- lary racemes or corymbs, rich in nectar, and at- tractive to bees; fruits, two small winged nuts, one or two seeded. With n few exceptions the entire order is embraced in the genus Acer, The best-known European species arc .4cer cam-
