334 Peach-Growing 



some of the larger types of reservoir heaters are used, it is 

 necessary to provide a storage tank or reservoir for the supply 

 of oil, a tank wagon for distributing the oil to the heaters, 

 besides thermometers, torches for use in lighting the pots, and 

 other minor supplies. 



The storage tank is usually made of cement or of sheet 

 metal and with a capacity sufficient to store a supply of oil 

 equivalent to 300 to 500 gallons for each acre that is to be 

 heated, depending on the probable amount of heating that 

 will need to be done. A smaller reserve would be unsafe, 

 since if several nights occurred in succession when it was 

 necessary to heat, as is sometimes the case, the only safety 

 lies in having an adequate supply on hand to meet the needs. 

 A cement storage tank is shown in Plate XXV (center), also 

 in the background a wagon-tank for use in distributing the 

 oil to the heaters. Some sheet metal tanks are also seen 

 in Plate XXV. 



With every heating it becomes increasingly necessary to 

 heat effectively when a critical temperature is reached, in 

 order to save not only the crop but what has been invested 

 in the previous heatings. 



In actual practice the pots are distributed in the orchard 

 as the blossoming period approaches and are filled with oil 

 ready to " fire." Their principal use is during the blossoming 

 period and they are lighted during that period if the tem- 

 perature in the orchard reaches 29° at the height of the tree 

 tops or by the time 30° is reached if the temperature is 

 dropping rapidly. 



There are a number of different kinds of torches and lighters 

 used in firing the oil in the pots. With one of the more effec- 

 tive kinds and everything working well, a man will light 250 

 to 300 pots in an hour. 



