440 ] Understanding the Weather 



Weather Study as a Hobby 



Weather forecasting provides many hobbies for older children. 

 They can construct instruments for a weather station of their own, 

 keep records of their observations, and study the weather maps in 

 the daily newspaper. 



ESTIMATING WIND VELOCITY 



Besides learning to know the clouds, boys and girls of even 

 first and second grade can have fun with weather in other ways. 

 While they may not be able to construct a wind vane, they can 

 learn to describe the direction of the wind by observing where the 

 narrow, weighted part of the vane points. 



They can also learn to judge the speed of wind fairly accurately 

 without an instrument. For example: If smoke is seen rising 

 straight up, the wind is moving less than a mile an hour. If the 

 smoke drifts in the wind though wind vanes are not turning its 

 rate is from one to three miles an hour. 



When wind keeps leaves and small twigs in motion, it is de- 

 scribed as "gentle" and is traveling from eight to twelve miles an 

 hour. When it raises dust and papers and keeps small branches 

 moving, it is "moderate" from thirteen to eighteen miles an hour. 



If you have trouble walking against the wind and it is bending 

 trees, it is "strong" more than thirty miles an hour. Wind that 

 does such damage as the uprooting of trees is a gale, and may move 

 up to seventy-five miles an hour. A wind in excess of this is a 

 hurricane. 



How to Make a Rain Gauge 



A small child who enjoys making things can construct a measur- 

 ing instrument for rain and snow a rain gauge. The weatherman 

 uses a gauge to measure periodic rainfall in an area, or the depth 

 of water that would lie on the ground if the rain had not escaped. 



All your child needs in order to make his own gauge is a large 

 watertight can eight inches across is close to the size used by the 

 United States Weather Bureau. You can also make a measuring 

 glass by pouring water to the depth of one inch in the can; then 



