WINDS AND WEATHER 



FIG. 56. An ane- 

 mometer. What is 

 the meaning of 

 anemometer? 



1. Why does smoke from a chimney fall toward the ground 

 before a storm? 



2. Why is air full of water vapor lighter than dry air? 



3. About how much force would a storm wind exert on you? 



4. How high will water rise in a pump? 

 Why? 



5. If water will rise only about 30 feet in 

 a pump, how is it possible to get water from 

 a well which has been drilled to the depth of 

 100 feet? 



6. Is smoke pushed or pulled up a chimney? 



7. Why do balloons rise? When will a 

 balloon stop rising? 



8. Why will a fireplace or stove smoke 

 when the fire is first started? 



9. How could the smoking be prevented? 



10. What is meant by a draft in a 

 chimney? 



11. Why do tall chimneys have a better draft than short chimneys? 



12. What is the best way to air out a room? 



WINDS AND WEATHER 



Isobars and Isotherms. The different stations send to Washington 

 each day their reading of the barometer. Lines called isobars are 

 drawn through the places where the barometric pressures are the 

 same. If the lines are close together there is a great difference 

 of pressure. Such a low is accompanied by a great deal of wind. 

 If the lines are far apart the opposite is true. Sometimes such 

 lows die out entirely. At other times they develop into vigorous 

 storms. These irregularities are rare, but when they do happen, 

 they, of course, upset the weather forecast. The lows travel on 

 the average from 500 to 1000 miles per day. 



The heavy lines are called isotherms. They run through places 

 of equal temperatures. 



Floor or Wall Weather Maps. A very helpful way to study the weather 

 conditions is to have a map made of linoleum large enough to place on the 

 floor. Such floor maps may be purchased for a small amount. Round discs 



