ELEMENTARY FORESTRY 



389 



of great interest, but the problems are so large that the 

 children cannot do much practical work with them. Cool 

 shade, however, is appreciated by all in hot weather, and 

 two thermometers, 

 one hung in the shade 

 of a tree, the other in 

 the open sunshine, 

 will tell an interest- 

 ing story. Protect 

 two thermometers 

 with a bit of paper 

 and bury the bulbs an 

 inch in the ground, 

 one in the sun, the 

 other in the shade. 

 If we do this about 

 three o'clock on a 

 warm day in June, 

 it will show how hot 

 the unprotected soil 

 becomes. Let as 

 many of the children 

 as have thermome- 

 ters in their homes 

 take a careful read- 

 ing at exactly 12.30 

 P.M., on some hot 

 sunny day, compare 

 the temperatures, and try to explain any differences that 

 may have been observed. This should be done on a clear, 

 hot day. 



Fig. 156. A Factory covered with 

 Woodbine 



(Photograph by Louis P. Nash) 



