Repository: UIHistories Project: Board of Trustees Minutes - 1869 [PAGE 177]

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163 svere wind blows, although there is a difference, perhaps, of ten egrees. Prof. BAKER—It is true that the evaporation caused by the pasage of the wind over the plants would affect them, as animals are ffected by it, and they would really suffer from the cold winds as nimals suffer from them, though the thermometer indicated the ame degree of cold in and out of the wind. Dr. GREGORY—Dr. Draper asserts that there is actual heat geneated in the tree. Bore a hole into a tree, and let the tree cool rom the warmth from boring, and insert a thermometer, and you rill find the tree of uniform temperature, warmer than the atmos>here. Now if this be so, the tree has the power to give off heat, ,nd the wind blowing upon the tree would liberate more heat and ake away moisture. These observations of Dr. Draper seem to ne to be exceedingly interesting, and worthy of consideration. Mr. PERIAM—My experience is, that a thermometer placed upon he east side of a belt of evergreens in the afternoon, at a distance )f 20 feet, when the wind is blowing from the west, will show a ange of ten degrees. The thermometer will sink ten degrees ower on the west side than on the east side. Mr. DUNLAP—It is easy to show the great advantage of evergreen belts in moderating the climate and warming the atmosDhere. They take in heat in the daytime and give it off at night. That is the reason for the pnctice of some in planting every fourth ree in their orchard an evergreen. It is simply a matter of expeience and observation that evergreens temper the climate. By Wanting these belts we will save our fruits, and may plant many r arieties in the north which would fail without this protection. Che practicability and advantages of this practice we expect to iemonstrate in this institution, and to illustrate upon these grounds his, one of the great and leading facts essential to success in fruit 3ulturf, especially in the northern part of the State. There is no question but there is a vast amount of truth in the assertion of Dr. Srregory, that trees give off heat. Let us recognize this important :ruth, and not cease our tree planting until we are fully protected oy these timber belts. Mr. ROBINSON—It will take twenty-four hours for frost to pene;rate to the heart of a tree two feet in diameter. It may be frozen 3xternally, and not frozen at the heart.