Atlantic Type of Coasts, xiv, 247, 249-50 Atlantic Volcanic Belt, xiv, 316 Atmometers, i, 88-9, 366 Atmosphere, anatomy of, i, 9-23; circulation (winds and storms), 123-40, xiv, 347-51; composition (gases), 9-16, viii, 66-8, 152; dense, effects of, iv, 31-2; density decrease upward, i, 16, 17, 171, 173, 303, iv, 108, 124, ix, 267-8, xiv, 354; density irregularities, optical effects, i, 171-2; disease germs in, 325-6; dust and smoke in, 52-65, 325, vii, 216-17, ix, 269; effect on colors of stars, ii, 296; effect on meteors, 283, 285, 290; effect on sunlight and colors, i, 165-6, 167-71; electrification, 144, 145, 146, 150, vii, 207, 212-13, 216-17; heat absorption by, iv, 194; heating of, by sun, i, 123; heat retention by, ii, 244, 382, iv, 183-4; height, i, 16-18, ii, 244, iv, 116; highway, i, 39-51; layers (see Stratosphere, Troposphere); light of, 164; magnifying of, by telescopes, ii, 98, 140, 141; meteorology, science of, i, 7; nitrogen fixation from (see Nitrogen Fixation); oxygen in upper, ix, 267-8; radioactive emanations in, i, 143; resources in, 24-38; theories of origin, iii, 160, 163; topographical work of, xiv, 62-79; weight, i, 23, ii, 279, v, 222-30 (see also Air) Atmosphere (unit of pressure), iv, 121, 123, 381, viii, 107 Atmospheric Acoustics, i, 186-96 Atmospheric Electricity, i, 141-63, vii, 201-19, 362; in climatology, i, 211; physiological effects, 330 Atmospheric Engine, Newcomen's, v, 144 Atmospheric Optics, i, 164-85, iv, 327-9 Atmospheric Pressure, amount and direction, i, 23, ii, 244, iv, 116-23, v, 222, viii, 107; amount at different elevations, iv, 124; body regulation to, x, 250; boiling point and, iv, 170, viii, 303; discovery of, iv, 114-16, 132, v, 112; early experiments with, iv, 29-30; equalization in ear, ix, 102; isobars, i, 125-26; life in relation to, ii, 245-48, xi, 53; measurement, i, 70-2, iv, 120, 121, 123, 124; physiological effect of changes, i, 303, 327-9; stratosphere in relation to, 20; unit of, iv, 121, 123, 381, viii, 107; variations with temperature, iv, 121-3, 124-5; weather and, i, 70, 237-8, 241-2 (see also Pressure Areas); winds in relation to, 124, 125-6, 127-9, 134-5; work done by, 25, v, 112-15, 137-8 Atmospheric Refraction, i, 167-74, 380, iv, 327-30; early studies of, ii, 32, 41 Atolls, xii, 41 Atomic Energy, ii, 384, v, 181, viii, 186-7 Atomic Numbers, viii, 183, 309 Atomic Theory, history and deductions, viii, 110; in Greek philosophy, xvi, 83-4, 87, 118; Leibnitz's, 117-18 Atomic Volume, determination, viii, 307