FIRST TEAR SCIENCE 



References are to pages. 



Potash, see Soils. 



Potential energy 45 



air plants 209 



See Energy. 



Prairies 402 



Prime meridian 32 



Prism 127 



Properties of matter, see Matter. 

 Proteins (pro' tee-ins) . 197, 235, 236 

 Pro'toplasm 186, 198 



growth in the body .... 236 



in bacteria 213 



Protozo'a 218 



Pupil of the eye 230 



sketch 231 



Radiation of heat 55 



Rainbow 128 



Rainfall 313-325 



and caves 319 



and lakes 322-325 



and geysers 319 



forms of, snow, hail, etc. . . 156 



in artesian wells 318 



in springs, hot and cold . 315-317 



map 155, 158 



measurement 154 



of the U. S 157-160 



Rain gauge 156 



Rapids 329-332 



Reflection engine 63 



Reflection of light . 58, 59, 62-64 



Refraction 60 



Respiration 225-227 



Ret'ina 230 



sketch 231 



Revolution of the earth . . 26 

 See also Earth. 



Rivers 332-361 



deltas 350 



development 342 



effects upon history . . . . 353 



of the U. S 854-360 



old ............. 340 



young 332 



Rocks, composition of . 76 



kinds 77 



igneous 77 



metamor'phic 79 



sedimentary 77, 78 



Rocks Continued 



soil 85-105 



structure 79 



subsoil 87 



varieties of stone 78 



weathering 82 



Roemer, Ole, Danish astrono- 

 mer (1644-1710), on light . 64 



Rotation of the earth ... 22 

 See also Earth. 



Sand spits 297, 307 



picture 298 



Sandstone 78 



See Soils. 



Sap 186 



Sap'rophytes 209 



Sargas'so Sea 282 



Satellites 11 



Saturn 4, 5 



picture 4 



satellites 11 



Sal'ivary glands 233 



Salt lakes 325 



Sand, see Soils 



Sand bars 297, 302 



Sand dunes 302, 387 



Sand reefs ...... 303, 307 



Sea, the 68-71 



currents 281 



depths 275 



divisions 272 



floor 275 



islands 288 



life 248-251, 269 



map of oceans 68 



shelf . 273 



size 272 



temperature 279 



tides . . . .- 284 



water 273 



waves 277 



See also Coasts, Beaches. 



Seal 251 



Seasons, change of .... 26-28 



Seaweed 248, 249 



of the Sargasso Sea ... * 282 



picture 248 



Sedimentary rocks .... 77 

 See Socks. 



