purpose of this bulletin is to give fruit aud vegetable growers such information as 

 will better enable them to solve their storage problems. 



TYPES OF STORAGES. 



There are two main types of fruit and vegetable storages, those using some 

 means of lowering the temperature below that of the outside air. called " cold " 

 storages, and those depending upon temperatures secured from atmospheric changes 

 called " cool " or " common " storage. The first class may be subdivided into those 

 using mechanical refrigeration and those using ice as a refrigerant. The other 

 a may be subdivided into various types of the common or cool storage. There 



I_OMS:TUO:KAI_ SEC.ON: 



Fig. 2. Diagram showing the arrangement of the farm cold storage of Fig. 1. 



are also pits and trenches, used more for vegetables than fruits. All these embody 

 similar general principles and are constructed to suit the commodity to be stored. 



MECHANICAL COLD STORAGES. 



Mechanical or chemical cold storage is based upon the laws of pbyscis which 

 show that beat is taken up by a liquid when evaporated, and that the condensation 

 of a gas varies with the temperature and the pressure applied. Thus such fluids 

 as ammonia, carbon dioxide, and sulphur dioxide, which have low boiling-points 

 (27.4 Fahr.. 110 Fahr.. and 14 D Fahr.. respectively), are used. At ordinary 

 temperatures these compounds are gases, but under extreme pressure and then by 

 cooling in condensers the gases are condensed to liquid form. Upon expanding in 

 pipes placed in the storage-rooms these liquids evaporate very rapidly, and in doing 

 so use up the heat within reach of the pipes, thus lowering the temperature of the 

 room, or producing cold in it. To secure this kind of refrigeration it is necessary- 

 to have a mechanical compressor with a power plant to operate it. This form of 

 refrigeration is most economically used in large cold-storage plants, but on account 

 of the expense is not ordinarily adapted to farm conditions. 



ICE COLD STORAGES. 

 DIRECT REFRIGERATION. 



Ice is now much made use of as a refrigerant. By placing ice in bunkers or 

 special ice-rooms, usually situated above a properly insulated storage-chamber made 

 with drip and condensation pans, a temperature of 3S C to 40 = Fahr. is secured For 



