264 NATURE-ISTUDY REVIEW [6:9-Dec., 1910 



the lid of a box, and a candle burning in one chimney to draw 

 the smoke from burning smudge held over the other one. This 

 will clear up the mystery of the attraction of the winds to the 

 center, even though it does not explain the rotary motion. Water 

 poured through a funnel or escaping through the exit of a sta- 

 tionary wash basin illustrates this movement (in a downward 

 fashion) though not explaining it either. 



A second examination of the weather maps will furnish a 

 good occasion to call attention especially to the winds flowing 

 from the south toward the center of the low, and to the decided 

 northward trend of the heat lines in the same general region. 



The region precipitation might be taken up in the same or in 

 a closely succeeding lesson. Weather-map studies will probably 

 be made in the winter months. The lows are more decided then, 

 the sequence of cold waves is more noticeable than at any other 

 time, while blizzards always arouse attention. Then Feburary 

 and March bring in those peculiarly elongated isobars, the 

 "troughs" with the frequent tornadoes in their southeastern 

 quadrant. If a number of maps have been accumulated through 

 several years, with the tornadoes marked on them in blue pencil, 

 as reported by the press, the series will have especial meaning 

 if brought out when some notable storm devastation is described 

 by the newspapers. 



After a thorough study of the lows, less time will be neces- 

 sary to grasp the essential features of the highs. 



Reference was made earlier to series of maps showing the 

 eastward movement of storms. This should be accompanied by 

 a discussion of the relation of trades to anti-trades, the lag of 

 the former and the drag of the latter, how the anti-trades serve 

 to pull the cyclonic disturbances eastward. Probably the effect of 

 the rotation of the earth in causing these is the least understood 

 by the teachers themselves of the many misunderstood points of 

 mathematical and meteorological geography. If the question of 

 rotation and its effects be the starting point, it is probably dull to 

 the last degree. However, if it is a last resort to account for 

 conditions we all know and recognize as highly important in our 

 every-day lives, it takes on an added interest. 



The United States Department of Agriculture has just issued 

 as Separate 505 the article in the 1909 Yearbook on "How Farm- 

 ers May Utilize the Special Warnings of the Weather Bureau." 



