384 FARM AND SCHOOL PROBLEMS. 



Get wilted or drooping plants during dry hot weather and show 

 that water is not furnished by the roots of the plant with sufficient 

 rapidity to replace the loss caused by evaporation from the leaves. 



Make a demonstration of the expansive force of freezing water. 



Show its effect in the disintegration of rocks. 



Place a small hollow glass tube in water to show effects of attrac- 

 tion and the capillary effect of water. Note that the water rises in the 

 hollow part of the tube above the level of the water on the outside. 



Pour a little ink into a saucer. Place a lump of loaf sugar in the 

 ink in such a way that but a small part of the loaf is in the ink. Ob- 

 serve that the whole loaf will become colored. 



Pulverize a lump of loaf sugar into a fine powdered form and try 

 the experiment as that with the solid loaf sugar and the ink and it will 

 be observed that the ink does not pass into the powdered sugar above 

 the level of the ink. 



Make a demonstration of the effect of a soil mulch by the side of 

 a plat of soil that is not mulched and note the effect on the conservation 

 of moisture. 



Plant ten rows of corn; try an experiment by treating part of 

 these rows with a soil mulch and leaving part without mulching. Note 

 the results in the growth and yield of the crop on each of the two 

 different plats. 



Questions. 



1. What do you understand by conservation of moisture? 



2. Do tile drains help to conserve moisture? How? 



3. What is a soil mulch? 



4. Does the depth of the mulch have any bearing on the amount 

 of evaporation? 



5. Why does poor soil dry out more rapidly than rich soil? 



6. Why does sand dry out more rapidly than peat? 



7. Why does alfalfa look green and continue to grow while other 

 plants die during a dry season? 



8. Name some trees that grow in wet or swampy places; some that 

 are found chiefly on high dry places. 



9. What is irrigation? Explain different methods of irrigation. 



10. Are there any advantages in irrigation outside of arid regions? 



11. What is dry farming? Where is it practiced? 



12. What is the average number of days in the growing season 

 in your locality? 



13. What is the average number of days in the growing season 

 between spring and autumn frosts? 



14. Explain how plant breeding has served to adapt crop grow- 

 ing to the length of the season between killing frosts. 



15. Describe an ideal growing day for corn. 



16. Describe an ideal day for cutting and making hay. 



