346 Fruit-growing in Arid Regions 



any one season, and for this period of burning it will ne- 

 cessitate the storing of about fifteen barrels of oil per acre. 

 From four to five tons of coal per acre would furnish about 

 the same protection as fifteen barrels of oil. Oil should be 

 stored in fairly tight tanks or cisterns. Cement cisterns 

 seem to be the cheapest storage reservoir. Apparently 

 any cistern that will hold water will hold oil. A good 300- 

 barrel cistern can be built on contract for about $150, 

 and if the grower wishes to do the greater part of the work 

 himself, the actual cash outlay need not be over a third of 

 this. A 100-barrel galvanized iron tank may be built for 

 about $75. Coal and the prepared fuels should be stored 

 from the weather to avoid deterioration. 



Heaters. At first many of the designers and manu- 

 facturers of orchard heaters apparently had the idea that 

 any receptacle that would hold coal or oil would make a 

 satisfactory orchard heater. This idea did not last long, 

 however, and many proposed orchard heaters were con- 

 demned, even before they had been tried in a practical 

 way; and after one year's test in actually fighting frost, 

 undesirable features have been emphasized in several of 

 the manufactured heaters, and the number of really useful 

 kinds has been still more reduced. 



An oil heater should be so constructed and should hold 

 so much oil as to burn for the maximum number of hours 

 during any one night. They should burn at least seven 

 hours without refilling. Refilling in the night is tedious 

 and expensive, and requires a great deal of help. An oil 

 burner that will burn for this period must be of the 

 reservoir type. That is, it must be so constructed that 

 only a part of the surface of the oil is exposed to the 



