CHAPTEK XY. 
CYCLONES AND ANTICYCLONES. 
Some days the wind seems to be changing from 
one direction to another, and even to a third and 
fourth; ray record shows that such changes usually 
accompany storms. I could not understand why this 
occurred until I studied the weather map issued 
by the United States Government. On my applica¬ 
tion to the Weather Bureau at Washington this was 
readily sent to me every day. 
There were many lines on this map that at first 
puzzled me. The most prominent, I discovered, were 
those that connected places which had the same baro¬ 
metric pressure. They varied in direction from 
almost circular or elliptical curves to slightly winding 
lines. For instance, the line marked thirty connected 
all the places where the barometer stood at thirty 
inches that day. The curve marked 30.2 connected 
all places where the barometer stood at that height, 
and so on. 
Where the barometer was highest the map was 
marked “ high,” and where it was lowest it was 
marked “low.” I soon noticed that the high and 
low points were continually changing, and, what sur- 
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