338 CITRUS FRUITS AND THEIR CULTURE. 



telegrams placed in the postoffice or in other conspicuous 

 places, that cold is to be expected. Much good results 

 from these forewarnings. In Florida, knowledge of an 

 approaching cold wave is also given by the railways. They 

 receive news of an expected fall in temperature and give no- 

 tice to those along the railroad line by special whistles 

 blown at intervals. Thus timely warning has frequently 

 been given. 



But, nevertheless, the grower should not be entirely 

 dependent upon some one else for his knowledge of what 

 is to be expected. Sometimes the weather bureau fails to 

 report the full extent of what is to be expected, or local 

 conditions may cause the cold to be more severe in one 

 locality than in another. Hence the citrus grower should 

 rely upon himself to some extent. 



THERMOMETERS. 



If a good alarm thermometer can be secured it should 

 by all means be purchased. A number of different kinds 

 have been placed on the market, but unfortunately they 

 are not all satisfactory, and usually they get out of repair 

 and do not read accurately after having been used for one 

 or two seasons. But if tested from time to time by compar- 

 ing them with a good standard thermometer, they may be 

 of considerable service. 



The outfit for setting up an alarm thermometer con- 

 sists of an electric bell, a battery, a thermometer, and suffi- 

 cient wire to permit the latter to be placed in a position 

 where it will accurately represent the temperature in the 

 grove. The bell should be placed where it will be heard 

 just outside a window being a good place. From this 

 the wires should lead out into the grove where they are 

 attached to the thermometer. 



