68 



GENERAL SCIENCE 



with concentric circles may be used for lows and highs. Black discs with 

 white circles represent the highs, and white discs with black circles the lows. 

 If five minutes of each period are used to arrange the discs according to the 

 weather map, predictions may be easily made. 



There should be three kinds of discs, some with the isobars close together, 

 some far apart, and some of medium separation. There should also be discs 



High, much Wind. Low, little wind. Low, with wind. Low, much wind. 



FIG. 57. A floor map for weather prediction. The low with light lines shows 

 where the low with the dark lines was the day before. All the highs and 

 lows for to-day and the day before should be placed on the floor map 

 each day according to the U. S. Weather Map. The action of highs and 

 lows according to direction and speed may be easily studied. 



marked "Yesterday" which should be placed on the map at the same time 

 to show the direction and distance the high or low traveled from one day 

 to the next. 



Another method is to use the map on the wall as a bulletin board. This 

 is not satisfactory, as it is not placed in true directions, north and south. 



Directions of Winds. When the wind sets in from points be- 

 tween south and southeast, and the barometer falls steadily, a 



