INDEX 



References are to pages. 



Seeds 202-205 



dispersal . .' 205 



germination 206 



Senses, the five 230-232 



Sextant 456 



Shales 68 



See Soils. 



Sidereal day (si-de're-al) . . 29 



Silt 95 



See Soils. 



Sink-hole 319 



picture 317 



Skeleton 224 



Sleeping- sickness 218 



Sleet 157 



Snow 156, 363 



See Glaciers. 



Soils 85-108 



agricultural 93 



alkali 103 



dry farming 101 



fertile 90 



irrigation . . ' 102 



loam 88 



local 86 



mulches 101 



silt 95 



soil water 96 



subsoil 87 



transported 86 



values : ... 106 



Solar day 28 



Solar system ....... 1-15 



ancient ideas of . . . . . . 3, 22 



diagram 6 



nebular hypothesis .... 6 



Sol'stlce, summer and winter . 27 



Sound 65 



Specific gravity of salt 



water 274 



Specific heat 56, 57 



Spectrum 127 



Spinal cord 225 



Springs, hot and cold .... 315 



sketch 314 



Stalac'tites 319 



Stalag'mites ........ 319 



Sta'mens 201 



Standard time 30 



map 31 



Starch 196 



Stars, the 1-3 



distance 5 



Stigma of a flower .... 201 



Stomach 234 



Sto'mata 200 



Storms 167 



maps 172, 173 



sudden changes 171 



weather bureau 174 



Stratified rock 79 



picture 80 



Strise (strl'ee) 368 



Style of a flower ..... 201 

 Suess, Eduard, Austrian geol- 

 ogist (1831 ) 70 



Sugar as food 235 



Summer 24, 25 



Sun 1-6 



center of solar system . . . 5, 6 

 effect upon the stars . . . . 2, 3 



energy of 45 



in plants 209 



revolution of earth around . 23-30 

 rising and setting . . . . 22, 23 

 size and distance . . 11, 12, 24. 25 



Sun dial 28 



picture 29 



Swamps 325, 329 



Telegraph . 

 apparatus . 

 invention . 

 wireless 



39,65 

 165, 166 

 , . 166 



, 167 



Telephone 39, 167 



Temperate zones .... 25-28 

 Temperature, average, see Cli- 

 mate . 279 



graphs 135 



maps 136, 137 



measurement 49-^51 



of land and water 137 



of the atmosphere 130 



of the ocean waters .... 137 



variations of 131 



Terminal moraine 367 



picture 369 



Terrestrial winds . . . . . 149 

 Texas fever . . 220 



