Cameras, 140, 171 Change cirrus, 37 ---- of velocity, 35 Cirriform top of thunder-cloud, 110 Cirro-cumulus, 45, 159 ---- nebulosus, 52, 159 Cirro-filum, 33, 156 Cirro-macula, 53, 159 Cirro-nebula, 26, 27, 155 Cirro-stratus, 45, 157 ---- communis, 47, 158 Cirro-stratus cumulosus, 48, 158 ---- nebulosus, 45, 158 ---- vittatus, 158 Cirro-velum, 24 Cirrus, 21, 155 ---- altitudes, 30, 149 ---- communis, 40, 157 ---- caudatus, 34, 156 ---- excelsus, 31, 156 ---- inconstans, 37, 157 ---- nebulosus, 36, 156 ---- ripples, 51 ---- ventosus, 32, 156 ---- vittatus, 41, 156 Cloud altitudes, 149 ---- nuclei, 3 ---- photography, 17, 165 Condensation, 93 Cooling by contact, 89 ---- by expansion, 92 ---- by mixture, 90 ---- by radiation, 88 Development, 175 Differential currents, 133 Diffraction, 63 Dimensions of clouds, 112 Dry fog, 73 Equilibrium, stable and unstable, 106 Exeter measurements, 137 Exposure, 167 Fall cloud, 81, 88 False cirrus, 110 Fog particles, 60 Fracto, 164 Gravitation, 4 Great waves, 129 Halos, 21, 22, 23 Heat cumulus, 85 ---- thunderstorms, 107 Hildebrandsson, 10 Hoar frost, 60 Howard, Luke, 9, 10 Intensification, 177 Interconvection, 125 International Code, 11 ---- Committee, 10 ---- System, 12, 71 Ions as nuclei, 92 Irregularities of ground, 39 Kepler, 4 Kew, 138 Ley, Clement, 24, 34, 55 Lightning, 114 Lower clouds, 71 Mammato-cumulus, 99 Meteorological Conference, 9 Methods of computing altitudes, 143 Munich, 9 Newton, 4 Nimbus, 74, 163 Nuclei, 92 Photographic methods, 17, 165 Rain-clouds, altitude, 76 ----, thickness, 81 Rate of fall of temperature, 94 Sandstorms, 117 Saturation, 87 Scotch mist, 73 Slow plates, 167 Spread of condensation, 57 Stable equilibrium, 106 Strato-cumulus, 77 Stratus, 72, 161 ---- communis, 77, 161 ---- lenticularis, 80, 98, 162 ---- maculosus, 78, 162 ---- radius, 79, 162 Subsidence of cloud top, 111 Surfusion, 61 Swing stand, 171 Turreted cloud, 66 Tycho Brahe, 4 Types, 8 Umbra and penumbra, 29 Undatus, 164 Unsaturated cloud, 101 Upsala, 10, 138 Wave clouds, 47, 119, 133 Wilson, C. T. R., 92 THE END PRINTED BY WILLIAM CLOWES AND SONS, LIMITED, LONDON AND BECCLES. * * * * * Transcriber’s Note Variations in hyphenation (i.e. thunderstorm and thunder-storm) have been retained. The following apparent typographical errors were corrected: Page 171, “focussed” changed to “focused.” (it should be focused on the horizon) Page 173, “aperature” changed to “aperture.” (the lens with its large aperture) End of the Project Gutenberg EBook of Cloud Studies, by Arthur W. Clayden