Los Angeles, 79; map of region between Santa Monica and, 67 Lower Cedar Point, Maryland, 87 (ill.) Ludlam Beach, New Jersey, 28 (ill.) Map, index of photographed areas, 75 Mapping, city, 79; from the air, 72 Mapping camera, opp. 22; experiment with, 53, 56 Maps, air mapping and, 74; air photograph adjustment, 35; use of air photographs in revising, 79 Marsh drainage, 27, 29 Marshes, 27; Chesapeake Bay, difficult to chart, 76 (ill.); details of drainage, 30 (ill.); details of frequently submerged, 31 (ill.); Far Rockaway, Long Island, 100 (ill.); salt marsh areas of coastal plain, 32 (ill.); salt marsh features, 92; stream development in tidal marsh, 28 (ill.) Mathews, Va., topographic sheet, 47 Mattaponi River, 29, 36, 38 Meanders, 33 (ill.), 38; abandoned, 50; Chattahoochee River, opp. 50 (ill. and map); marsh, 27 Menoher, C. T., xi Mexican border, 71 Miami, Fla, channels and shoals, 96 (ill.), 102; dredged channel, 97 (ill.), 102 Michigan, glacial drift plain, 52 (ill.), 53 (map) Military Academy. _See_ United States Military Academy Military observation, 4, 6 Mjöberg, Eric, 71 Monument Avenue, Richmond, Va., 12 (ill.) Moraines, 52 (ill.), 53 (map), 55, 57; Mt. Shasta, 59 (ill.) Mosaics, 12, 20, 22 (ill.); Anacostia River, D. C., land along, opp. 22 (Fig. 13); Columbus, Ga., opp. 26 (Fig. 17); Mulberry Island, Virginia, 24 (ill.); Rochester, N. Y., opp. 74 (ill. and map) Mountains, 22, 27; features, 57; of volcanic origin--Cinder Cone, etc., California, 62 (ill.), 63 (map) Mud flats, 36; coastal, 41; stream channels and, 42 (ill.), 43 (ill.) Mulberry Island, Virginia, 24 (ill.), 25 (map) Mumfort Islands, Virginia, 77 Muskrats, 29, 39 Napatree Point, Rhode Island, 92 (ill.) Naval Academy. _See_ United States Naval Academy New angles, 7 New Guinea, 7 New Kent, Va., topographic sheet, 27, 35, 37 New Point Comfort, spit, 90 (ill.) New York Connecting Railroad Bridge. _See_ Hell Gate Bridge New York Harbor, xi Newport News, Va., xi, 11; shipyards, 14 (ill.) Oblique photographs, 1 Ocean City, N. J., 32 (ill.); hook, 89 (ill.) Oil, prospecting for, 71 Ores, 69 Orientation, 61 Oxbows, 33 (ill.), 50 Pamunkey River, 29, 36, 38; Cousaic Marsh, 31 (ill.); Eltham Marsh, 36 (ill.), 37 (map): marshes, 27; Sweet Hall Marsh, 34 (ill.), 35 (map) Panchromatic film, opp. 74 Paris, mapping, 79 Pecos River, 70 (ill.) Pennsylvania Avenue Bridge, 13, opp. 22 (ill. and map) Perry, Commodore, 72 Photographs, mosaic. _See_ Mosaics Photography, airplane. _See_ Air photography Piankatank River, Virginia, drowned terraces at mouth, 46 (ills.) Pictures from new angles, 7 Plains, glacial drift, 55; glacial drift, Michigan, 52 (ill.), 53 (map); photographing from the air, 50 Popes Creek, Virginia, 83 (ill.) Poquoson River, Virginia, 76, 94 (ill.) Port Clinton, Ohio, 72, 73 (ill. and map) Potomac Park, Washington, D. C., 16 (ill.)