EXERCISE A-15. TO SHOW HOW THE TEMPERATURE 

 OF THE SOIL IS AFFECTED BY THE SLOPE. 



Equipment: Three boxes, 6''X12''X12''; three ther- 

 mometers;* soil sample. 



Method: Nmiiber the boxes 1, 2, and 3, fill with the 

 same kind of soil and set them in the sunhght, side by 



Fig. 15. — Arrangement of Boxes to Show the Effect of Slope upon 



the Temperature of the Soil. 



side. Arrange the boxes so that No. 1 will stand level, 

 No. 2 slope toward the south (four inches slope to the 

 foot) and No. 3 slope toward the north at the same angle. 



* The thermometers should be tested by placmg the three side by 

 side in a tumbler of water and after stirring the water for a few minutes 

 compare the readings on the thermometer scales. If they do not read 

 the same a suitable correction must be applied. 



31 



