PROTECTING ORCHARDS ACJAIXST FROSTS. 273 



zero is cold enough to cause uneasiness. When the petals 

 are otf tliey can siand 30 degrees above zero. AVhen tlie 

 "shucks" (calvx tubes) are beginning to fall oft" 32 degrees 

 above zero is the danger point. 



The above figures will serve as a guide to the fruit grower 

 as showing the proper time to light the fires in the orchard. 

 It was said that many persons light the fires too soon and in 

 such cases it is not onlj' a waste of fuel, but it does no good 

 whatever in any way unless they have plent}' of material on 

 hand to keej) the fires going afterwards until all danger from 

 the cold is passed. 



Most people who have lived in the country very long know 

 weather conditions well enough to have a pretty good idea 

 when there is danger of a heavy frost. Generally it may be 

 said that if other atmospheric conditions are favorable for 

 the occurrence of frost as a rule, frost may be exi)eeted when 

 the temperature falls to a point 8 or 10 degrees above freez- 

 ing, that is, when the thermometer reads from 40 to 42 de- 

 grees F. 



PREPARING THE HEATERS AND FUEL. 



In using oil heaters everything should be in readiness for 

 lighting the fires Aveeks in advance of the time they are ex- 

 pected to be needed. The pots must not only be distributed, 

 but they must be filled with oil. One method of filling is to 

 pass along the row w- itli a barrel of oil on a sled. By means 

 of a suction pump and a piece of hose the oil is quickly trans- 

 ferred to the pots. Another way is to have an open barrel of 

 oil and fill the pots with a bucket. After being filled the pots 

 should always be covered so as to i3revent rain or dust from 

 falling in them. Lids are made to fit all of the different sizes 

 of heaters and these should b(^ purchased along with the pots. 



When the heaters are filled a v/ick for lighting should be 

 I)rovided. Since the pots are plain, open vessels, a wick is 

 best made by using a small roll of grass or straw which 

 touches the oil and hangs over the edg(^ of the heater. In 



10 



