214 



ROCKS AND SOILS 



14. Capillary action causes water in soil to 



rise fall evaporate flow away condense 



15. Swampy lands have been reclaimed by use of 



irrigation dry farming capillarity artificial 

 drainage 



16. An acid condition of the soil can be corrected by use 

 of salt clover lime manure phosphate 



SUPPLEMENTARY MATERIALS 



Reading suggestions 



Atkinson, The Strange Adventures of a Pebble 

 (Scribner) 



Mix, Mighty Animals (American Book) 



Fairbanks, Stories of Rocks and Minerals (Educ. 

 Pub.) 



Grew, The Romance of Modern Geology (Lippin- 

 cott) 



Seers, The Earth and Its Life (World Book) 



Tarr and Engeln, New Physical Geography (Macmil- 

 lan) 



Cole, Rocks and Their Origin (Macmillan) 



Bradley, Earth and Its History (Ginn) 



Reed, The Earth for Sam (Harcourt) 



Husband, A Year in a Coal Mine (Houghton) 



McCabe, Ice Ages (Putnam) 



Whitlock, The Story of the Minerals (American Mu- 

 seum of Natural History) 



Reports which may be prepared 



1. The planetesimal hypothesis of the formation of 

 the universe 



2. Laplacian hypothesis of the formation of the 

 universe 



3. The Mammoth Cave of Kentucky 



4. The Luray Caves of Virginia 



5. How mountains were formed 



6. Irrigation projects in the southwestern part of 

 the United States 



7. Factors which determine soil fertility 



8. Fertilizers 



9. Life in the Ice Age 



10. How stalactites and stalagmites are formed in 

 caves 



11. The dangers of dust storms 



12. How soils are conserved 



Great scientists you should know about 



1. Laplace 



2. T. C. Chamberlin 



3. F. R. Moulton 



Investigations and things to do 



1. Make a collection of rocks and minerals. Identi- 

 fy and label as many of them as you can. 



2. Visit a museum and examine the specimens of 

 rocks and minerals. You may find it interesting 

 and valuable to compare your own specimens 

 with those in the museum. 



3. Make excursions into the surrounding country 

 and note all the effects of weathering that you 

 find. 



4. Find out whether the section in which you are 

 living was ever passed over by a glacier. If it 

 was, make a field trip to find some evidences of 

 it. Report your findings to the class. 



5. Investigate carefully the kinds of soil in your 

 community. Examine specimens for color, tex- 

 ture, water-holding ability, and fertility. 



6. From what sources are our artificial fertilizers 

 such as nitrates and phosphates obtained? 



