224 GARDENS AND THEIR MEANING 



SUGGESTIVE EXPERIMENTS SUITABLE FOR YOUNG 

 GARDENERS 1 



I. PRESENCE OF AIR IN THE SOIL 



(a) Materials. Soil and flowerpot or can, beaker of water. 

 Directions. Submerge pot of earth in water. Air bubbles will 



arise from soil. Same may be shown by clod of earth in water. 



(b) Materials. Six beakers, graduate, soil samples. 

 Directions. Put a measured amount of soil (about 250 ccm.) into 



each beaker. Pour water into the beaker from the graduate (con- 

 taining a measured quantity) until it rises to the surface of the soil. 

 Find how much water it takes in each case, recording results. 



II. SOIL TEMPERATURES 



Materials. Two or three thermometers, 



Directions. Take this excursion on a bright spring day when 

 plowing begins. To take the temperature of a soil, bury the bulb 

 of the thermometer about three inches deep in the soil. Very 

 great care must be taken not to break the thermometer. Leave 

 the thermometer imbedded for from 10 to 20 minutes, so as to 

 obtain correct results. Take the temperature of the soil on a 

 northern and on a southern slope, also of clay and sand, of un- 

 plowed and freshly plowed fields, and of grass and tilled fields. 

 In each case try to find adjacent soils that are alike except in the 

 two things to be compared. 



You will probably find that the one mentioned second in each 

 case is the warmer. Why ? 



III. CAPILLARY RISE OF WATER IN SOILS 



Materials. Two small glass plates, three glass tubes (three feet 

 long and from one and one half to two inches in diameter), pan of 



1 Adapted from Public School Agriculture, Massachusetts Agricultural 

 College. 



