A GRADED COURSE OF NATURE-STUDY 469 



about the great glacier and some of its effects. Avoid all 

 theory. This topic should come after, and in connection 

 with, the study of glaciers in geography. Glacial scenery — 

 hills, lakes. (324, 332, 336, 339, 342, 344, 475.) 



Weather Study: The barometer.* Keep record of 

 pressure for several weeks. Review cause of wind.* Rela- 

 tion of temperature and pressure to wind. Follow the 

 course of a storm with barometer records. Show and read 

 weather bulletins, weather maps. Note barometer in con- 

 nection with the daily bulletins. Meaning of isotherms and 

 isobars. Observe the predictions and the verification. Fol- 

 low in the papers the course of some "cyclonic" storm or 

 cold wave. Note the course taken in North America. Note 

 damage done to crops, shipping, etc. Read or tell about the 

 United States Weather Bureau, its purpose, benefit to sailors, 

 farmers, etc. Make quite simple. (326, 328, 331, 345, 329, 



334, 338, 340.) 



Physics: Review winds (see weather, above.) Con- 

 struct a barometer.* Explain the principle. Use. Keep 

 barometer record. Perform simple experiments to show 

 effects of atmospheric pressure. Apply to pumps.* Use 

 models and diagrams. Observe a cistern pump for con- 

 struction.* A little about the air-pump. A bicycle pump.* 

 Compressed air — bicycle tire, pneumatic delivery in stores. 

 (251, 250, 25s, 257, etc.; 317, 318. Barometer — also 326, 

 327, 328, etc.) 



Inventions: The balance.* Construction, equal arms. 

 Simple talk with experiments about weight, gravity, falling 

 bodies. Make informal and observational, rather than 

 based on reasoning. How a lever is used. What is gained 

 by it? What is meant by "purchase"? What is a see- 



