CAPILLARITY AND OSMOSIS 117 



6. How does the split in the pen make the ink flow more uniformly? 



6. From which would you expect more water to evaporate, a compact 

 or a loose soil, both being equally wet? Why? 



7. In which would you expect the soil water to rise higher, a sandy 

 or a clay soil? Why? 



8. How would a mulch of straw, leaves, or even dry earth, prevent 

 the moisture in the soil from escaping? 



9. In planting small seeds, it is customary to firm the soil over them 

 to keep them moist. How does firming the soil accomplish this? 



10. Why is salt likely to become lumpy in wet weather? 



11. When moss is soft to the tread, it is regarded as a sign of an 

 approaching storm. Why? 



12. When clothes are sprinkled for ironing, why are they usually 

 rolled up and allowed to lie for a short time? 



13. Why do doors, drawers, and windows often stick in wet weather? 



14. In old houses, the floors and stairways often snap and creak before 

 a change in the weather. Explain. 



15. In quarries, pieces of rock are sometimes broken off by the simple 

 expedient of drilling several holes in a row where the break is desired, 

 fitting each hole with a plug of dry wood and then wetting the plugs. 

 Explain. 



16. Why may a wooden tub or barrel fall to pieces if not kept moist ? 



