7. Why does the exhaust steam from an engine appear to have so much greater volume on a cold day in winter than on a warm one in summer?
8. What causes an unfrozen pond or lake to "steam" on a very cold day in winter, or on a very cool morning in summer?
9. As the air on a mountain top settles down the sides to places of greater pressure, how will its temperature be affected? its relative humidity? Explain.
10. On our Pacific coast, moist winds blow from the west over the mountains. Where will it rain? Where be dry? Explain.
[CHAPTER VIII]
HEAT AND WORK
(1) Heat Measurement and Specific Heat
177. Specific Heat.—In the study of density and specific gravity it is made clear that different substances differ widely in the amount of matter contained in equal volumes, e.g., lead is much denser than water. The study of the relative densities of substance is usually considered under the subject of specific gravity.