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MANUAL OF GENEEAL AGRICULTUEE. 



7. EFFECT OF COLOR ON SOIL TEMPERATURE. 



Materials: Two cigar boxes, soot, slaked lime, two 

 thermometers, seeds. 



Place well pulverized moist soil into two cigar boxes, 

 filling them about half full. In one-half of one box, bury 

 twelve seeds 1/2 inch deep, using bean, corn, wheat, or any 

 other quick germinating seeds which may be on hand. In 

 the other half plant 12 seeds of some other plant. Cover 

 both plantings with chalk dust, slaked lime or white ashes 

 to a depth of % inch. 



In the same manner plant the same number and the 

 same kinds of seeds in the other box, but instead of using 

 light colored covering, use soot. 



Each time the class meets after the second day ob- 

 serve the number of plants showing above the surface, 

 keeping a record of the dates and kinds sprouted on the 

 side of the box. In the morning of a clear day insert a 

 thermometer into each box to about the depth of the 

 sprouted seeds. After a few minutes, when the thermom- 

 eters have become adjusted to the new temperatures, take 

 the readings. Continue to take the readings hourly 

 throughout the day. Record the results as follows: 



DAYS TO SPROUT 



TEMPERATURE 



Light Soil 

 Beans Peas 



Dark Soil 



Time 



Beans 



Peas 



8A.M. 

 9A.M. 



10 A.M. 



11 A.M. 



12 M. 

 1P.M. 

 2P.M. 

 3P.M. 

 4P.M. 

 5P.M. 



Light I Dark 

 Soil Soil 



Question : 

 Why? 



Which soil shows the higher temperature ? 



