STUDY OF WEATHER 183 



ture the terms warm, hot, very hot, cool, cold, very cold, 

 and chilly may be used. The direction of the wind 

 may be indicated by an arrow. An arrow pointing 

 toward the top of the chart indicates a wind which is 

 traveling north. Is a wind named from the direction 

 it is going, or the direction from which it is coming? 

 What is meant by velocity of the wind? The follow- 

 ing terms are in use by the United States Weather 

 Bureau: calm, when there is no perceptible wind; light, 

 just moving branches; brisk, swaying branches; high, 

 swaying whole trees. 



Under sky, record whether it is clear, partly cloudy, 

 or overcast. 



Precipitation means falling weather of any sort, rain, 

 sleet, snow, etc. Under remarks, record any item of 

 interest that does not appear under the other headings. 

 Thus, for September 15th, a heavy shower this afternoon, 

 or, for September 16th, a slight frost last night. 



At the end of each month have the pupils make a short 

 summary derived from their observations. How many 

 fair days? How many cloudy? How many in which 

 there was precipitation ? What was the general direction 

 of the wind for the month ? What was the direction of the 

 wind when the temperature was warmest? When the 

 temperature was coldest? From what direction did the 

 rain come? From what direction did the snow come? 

 What was the direction of the wind during the cloudy 

 weather?, etc. 



Have them note other relations. Is a cloudy night 



warmer or colder than a clear night? You often hear 



people say in the early fall: "If it clears it will freeze to- 

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