LOCATING THE CITRUS GROVE. 227 



able. Even a few feet of rise suffices to protect the trees. 

 Frequently it may be observed that the lower portion of 

 a grove is badly frosted while the remainder, only a few 

 feet higher, escapes. Sometimes the banking of the cold 

 air is materially increased by a wall of timber so situ- 

 ated, adjoining the lower portion, as to prevent air 

 drainage. 



This trouble may be obviated by opening up the tim- 

 ber belt sufficiently to allow the cold air to drain off. 



It will be seen from the above, that if the grove or 

 a portion of it be situated in a depression, air drainage 

 may be actually injurious, but on the other hand the fact 

 that the cold air flows off into the lower areas may be 

 turned to good advantage, if precaution is taken to select 

 a proper location. The site for the grove in regions sub- 

 ject to damage by frost should be selected on sloping or 

 elevated ground, to permit the removal of the cold air. 



It is very desirable to locate the grove on the shore 

 of a lake or other body of water. The proximity of such 

 bodies of water have much to do with equalizing the tem- 

 perature. In Florida, as shown in Chapter XXXV, there 

 are large numbers of lakes and rivers and in that district it 

 is best to locate the grove, if possible, either on the east or 

 south side of a lake. The freezes which have struck the 

 State have generally come either from the north or north- 

 west. If the lake be of considerable depth, the water does 

 not part with its store of accumulated heat so rapidly as 

 when it is shallow and the heat slowly given up will in 

 some measure raise the temperature. In prevention of 

 frosts, bodies of water play an important part. The heat 

 which they have accumulated during the day is given off 

 slowly during the night thus raising the temperature of 

 the air over the adjoining land. 



