Page:Handbook of Meteorology.djvu/304

 Photogrammeter, 71

Pillar of light, 122

Platte River, 131

Precipitation, intensity of, 226

— measurement of, 97

— summer, 107

Pressure, actual and recorded, 47

— and altitude, 48

— atmospheric, 39

— barogram of, 45

— daily ranges of, 44

— diurnal changes, 44

— mean for January (map), 40

— — July (map), 42

— — over earth, 44

— measurement of, 39

— semi-diurnal. Mt. Vernon, 46

— units of, 39, 193

Prevailing westerlies, 50

Prudden, T. M. quoted, 132

Psychrometer, sling, 217

Rainbow, 122

Rain and visibility, 141

— drops, size of, 97

— insurance against, 107

Rainfall, annual (map), 98

— cyclonic storms, 100

— Pacific Coast of U. S., 99

— Torrid Zone, 99

— Western Europe, 99

Rain gauges, Ferguson, 230

— — Friez recording, 224

— — installation of, 229

— — Marvin recording, 223

— — pit, 229

— — Short and Mason, 225

— — tipping-bucket, 224

— — Weather Bureau, 222

Reed, W. B., quoted, 83

Return trade wind,

Roaring forties, 50

St. Elmo fire, 115

Santa Ana wind, 55

Saturation, 6, 214

Scud, 81

Shaw, Sir Napier, quoted, 137, 188

Simoon, desert, 55

— electrical effects, 109

Sleet, 103

Sling psychrometer, 217

Smith, J. Warren, quoted, 119

Smoke and cloud formation, 57

— and visibility, 142

Snow, 101

— effect on visibility, 141

Snowfall, distribution of, 102

— measurement of, 230

— of Pacific Coast, 230

Snowflakes, structure of, 101

— photography of, 102

Snow gauges, 231

Solar constant, 21

Sounding balloons, 57

Specific gravity, 15

Storm cards of hurricane, 155

Storms, anticyclonic, 152

— classified, 150

— cyclonic, 101, 149

— dust, 142, 163

— forecasts, 151

— form and dimensions of, 156

— hail, 105

— ice, 103

— probabilities, 157

— secondary, 158

Storm tracks of U. S. (map), 154

Stratosphere, 27

— humidity of, 28

— movement of air in, 57

Summer precipitation, 107

Sun pillar, 122

Sunshine in U. S. (map), 248

— measurement, 250

— results of, 251

Sunshine recorders, 242, 245

— — Campbell-Stokes, 246

— — Marvin, 247

photographic, 247

Temperature, absolute, 177

— and altitude, 26, 57

— and latitude, 29

— radiation, 36

— and wind, 35