THE FRUIT GROWER S COLD STORAGE PLANT. 249 



terns have not given satisfaction and in a great majority of cases 

 have been abandoned. 



A refrigerating machine will produce good results if it is care- 

 fully handled and operated under favorable conditions and run 

 continuously, or nearly so, during the twenty-four hours of the day. 

 A refrigerating machine operated on the ammonia system (which 

 is the common machine system in use) is expensive to install, com- 

 plicated (o operate and, in the smaller machines especially, very 

 liable to break down or get out of order. The ammonia system re- 

 quires considerable skillful attention and a large amount of power 

 to operate it. There are very few, if any, successful small ma- 

 chines on the market, although their makers claim them to be prac- 

 tically automatic in their operation and to require very little at- 

 tention. It may be stated in a general way that a refrigerating ma- 

 chine is practically out of the question for the storage of fruit in 

 country locations, owing to high first cost and difficulty and ex- 

 pense of operation. 



The poor results obtainable with direct ice cooling and the dif- 

 ficulty and expense of operating an ammonia machine led to the 

 invention of the "Gravity Brine System." This is a system of iron 

 piping through which circulates chloride of calcium brine. There 

 are two sets of pipe coils connected together by suitable supply and 

 return mains. One set of coils is located in a tank and surrounded 

 by ice and salt. The second set is located at a lower level in the 

 room or space to be cooled. As the brine in the coils in the tank 

 is cooled by contact with the ice and salt it becomes heavier and cir- 

 culates down into the coils in the storage room, where it displaces 

 the comparatively warm brine, which rises into the tank coils and is 

 cooled in turn. This circulation will, of course, continue as long 

 as the supply of ice and salt is maintained in the tank. Any tem- 

 perature down to 10° above zero may be produced and maintained 

 with this system, but 30° F. is as" low as fruit-growers are interested 

 in. Owing to the steadiness or balance which the brine circulation 

 gives, much more uniform temperatures may be had with the 

 ""Gravity Brine System" than with a refrigerating machine. 



The advantages of the "Gravity Brine System" over direct ice 

 cooling are a control of temperature and comparatively dry air in 

 the storage room, its advantages over a refrigerating machine is a 

 better control of temperature at a much lower cost and an absolute 

 surety against break-down. 



It has been stated in some of the horticultural papers that a 

 cold storage plant could be built at a cost of one dollar per barrel 

 of capacity. A first class house cannot be built at any such cost, 



