246 ROCKS AND SOIL 



3. You find a small bed of fossil clam shells near your home. 

 What kind of rocks do you expect to find above and below 

 them? 



4. Classify the following agents as chemical, or mechanical : 

 frost, wind, lightning, oxidation, rain, acids in soil, plants, carbon 

 dioxide. 



5. If you were to study your locality to find evidence of the 

 action of glaciers, what would you look for? 



6. How do the farmers in your locality aid nature in the pro- 

 duction of crops? 



7. What forces and agencies in your locality make plant life 

 possible? 



REPORTS UPON OUTSIDE THINGS I HAVE READ, 

 DONE, OR SEEN 



1. Report upon an article related to some topic discussed in 

 this unit. The article may be from a current number of a science 

 magazine or from some popular science book you have read. 



2. Present-day glaciers of the world. 



3. How a river makes soil. 



4. The varieties of rock in my state. 



5. My visit to the museum to study minerals. 



SCIENCE RECREATION 



1. Make a collection of minerals and arrange them according 

 to their hardness ; try the scratch test. The scale of hardness for 

 minerals is : 



1. Talc easily scratched by fingernail. 2. Gypsum 

 scratched by fingernail, but not easily. 3. Calcite scratched 

 easily with knife point, but not with fingernail. 4. Fluorite 

 scratched with knife, but not easily. Does not scratch glass. 



5. Apatite scratched with knife. Scratches glass with difficulty. 



6. Felspar will scratch glass easily. Can be scratched with 

 knife with difficulty. 7. Quartz will scratch glass easily. Can- 

 not be scratched with knife. 8. Topaz harder than quartz. 

 Is scratched by corundum and diamond. 9. Corundum harder 

 than topaz. Is scratched by diamond. 10. Diamond hardest 

 mineral. Is scratched by none, but will scratch all others. 



2. Make a collection of pictures taken from travel folders 

 illustrating some of the work of erosion in this country. 



3. If you live in a glaciated region, make a report on the effect 

 of glaciers on your township. 



