358 CITRUS FRUITS AND THEIR CULTURE. 



half of our baskets) ; 2:00 o'clock 22 degrees; 3:00 o'clock 

 24 degrees ; 4 :00 o'clock 26 degrees ; and the thermometer 

 did not register 26 degrees after this time. 



"Please note that the thermometer registered below 

 28 degrees for three and one-half hours before the pan 

 of water was frozen over, and for four hours after the 

 temperature was aft'ected by our fires. Also that the drop 

 in temperature up to the lighting had been about 2 de- 

 grees per hour, which was checked and forced up, until, 

 when all our fires were going, it reached 26 degrees, and 

 did not again get below this, notwithstanding the fact 

 that the temperature usually continues falling until sun- 

 rise unless a breeze springs up, which in this case did 

 not occur. Notwithstanding this, however, our thermom 

 eters registered below 28 degrees for ten hours without 

 injury to our trees and lemons. I cannot account for this, 

 except that possibly after we lighted our fires, the heat 

 and smoke rising from them and hanging over the grove 

 acted as a sort of blanket, preventing the cold air from 

 settling. Our thermometers are hung on posts about 

 three feet from the ground, and it has been suggested to 

 me as an explanation of the low temperature shown by 

 the thermometers resulting in no injury, that the heat ra- 

 diating from the baskets would radiate in streaks, and 

 that the whole body of cold air would not necessarily 

 become heated, and the thermometers being protected 

 by the post and boxing, would not be sensitive to the heat 

 radiation, and would therefore read colder than the heat 

 was in reality. I have since regretted that I did not take 

 the temperature ten and twelve feet from the ground. 



"In a few of the coldest spots in our grove, there is a 

 slight singeing of the tenderest leaves, but nothing of any 

 consequence. The portion of the grove where this singeing 



