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AGRICULTURE 



EXPERIMENTS 



i. Put in each of two bottles of water a cutting of wandering jew, 

 or some other easily rooted plant. Pour melted wax into one bottle, so 



as to cover the surface of the water and 

 exclude air. What is the result? 



2. Put a flourishing plant in a tin can of 

 fertile earth. Keep it flooded with water 

 and notice the result. 



SOIL TEMPERATURE 



Conditions affecting Climate. Soil 

 temperature, or its condition with re- 

 gard to heat and cold, is determined 



To the cutting on the left, air is freely ,.,,. ^, n . -, 



admitted; it is excluded from that chiefly by climate. Climate, you know, 

 on the right by melted wax poured i s affected by many things, nearness 



over the surface of the water. ,, , . , , 



to the ocean, ocean currents, height 



above sea level, distance from the equator, prevailing winds, and 

 the presence or absence of forests. 



Conditions affecting Soil Temperature. But there is often 

 difference in the temperature of soils exposed to the same climate. 

 The slope of land affects its warmth. A field that slopes to the 

 south receives more of the sun's heat waves than one inclining to the 

 north, and so is warmer. Color affects temperature. A dark soil 

 is warmer than a light one, as a black dress is warmer than a white 

 one; the dark color absorbs more heat waves. 



A wet soil is colder than a dry one. Many of the heat waves 

 which fall on wet land are spent in evaporating its surplus water; 

 the heat waves on a dry soil are used to raise its temperature. You 

 have probably had a personal experience which illustrates this. 

 Were you ever caught in the rain and compelled to remain awhile 

 in your wet clothes? It may have been summer, but unless you 



