4 THE APPLE 



Near other smaller lakes or even rivers or ponds, if the orchard 

 is properly located to receive the maximum effect of the water, it 

 may be quite profitable even in an otherwise frosty region. The 

 best location adjoining these bodies of water seems to be on the 

 south or east side, because during frosty nights the wind is often 

 from the north or west ; therefore the warmer air would have a 

 tendency to be blown toward such a location. 



Positive figures are not obtainable upon the amount of heat given 

 off by a certain body of water, but the following may give some 

 idea of the amount of heat given off by water as it cools during 

 the night. 



According to O'Gara's x figures, if seventy oil pots per acre are 

 sufficient to hold the temperature in an orchard, during quite a 

 frosty night, 4 degrees above that of the air surrounding the 

 orchard, actual tests have demonstrated that a body of water one 

 foot deep and an acre in extent will give off considerably more heat 

 than the seventy oil pots during the night where there is a decrease 

 in the surrounding temperature of 1 degree per hour. ■ 



Not all of this heat from the water is available to an orchard. 

 However, if it is properly located a favorable wind would cause 

 the heated air to affect the trees appreciably. 



Records of temperature to show this effect are occasionally avail- 

 able. For a period of twenty years records were kept at Coopers- 

 town, New York (which is situated near the southern part of 

 Otsego Lake), and also at New Lisbon, New York (about fifteen 

 miles inland and toward the west from Cooperstown). These two 

 places are ideal for comparison in regard to this matter, owing 

 to their being practically at the same elevation. 



At Cooperstown the average date of the last frost in the spring 

 has been ascertained as May 8. Killing frosts have occurred after 

 May 1 in only twelve out of twenty years. During this time no 

 frost has been recorded later than June 1. In comparison with this, 

 New Lisbon's average last frost in the spring is May 23, about 

 fifteen days later than at Cooperstown. During the twenty years 

 there has been a frost each year later than May 1. In fact, four 

 killing frosts have occurred later than June 1 . The average grow- 

 ing period between frosts at Cooperstown is one hundred forty-eight 



1 T. J. O'Gara, investigator, Rogue River Valley, Oregon. 



