STORAGE 



1729 



meaus or by ice, cold storage can only 

 be accomplished by maintaining a de- 

 sired temperature over a long period. 

 In order to secure this, the compart- 

 ments in which the products for storage 

 are to be held must be as perfectly in- 

 sulated from outside heat as possible. 



Successful experimental refrigeration 

 by mechanical means was accomplished 

 as early as the middle of the eighteenth 

 century, but no successful commercial 

 application of cold storage was made un- 

 til after the invention of Lowe's "car- 

 bonic arid" machine in 1867, although 

 the present growth of the industry is 

 due to the invention of the ammonia 

 compression machine by Professor Carl 

 Linde in 1875. 



The process was first extensively ap- 

 plied to the preservation of meats, fish, 

 etc.. but as early as 1881 the Mechanical 

 Refrigerating Company of Boston opened 

 a cold storage warehouse, which marks 

 the beginning of mechanical refrigera- 

 tion as applied to horticultural products. 

 Other companies were then organized, 

 until now there are about 1,200 refriger- 

 ating plants in the United States, of 

 which about 000 are used mostly for 

 horticultural products. Foreign coun- 

 tries are now following the example of the United 

 States, and London, Liverpool, Glasgow, Paris and 

 other European cities offer facilities for storing such 

 products. In the United States, Chicago is the great 

 center for fruit storage, single firms holding as many as 

 100,000 barrels a year. Apples are the principal storage 

 fruit, good winter sorts holding their form, color and 

 flavor better than any other commercial fruit when held 

 for long periods in cold storage. Another reason why 

 the apple is a favorite in cold storage is that people use 

 it continuously over a long period. A good apple is 

 always a relish. The apple, too, is the fruit which best 

 pays the producer to hold in cold storage. 



From the nature of the case, mechanical refrigeration 

 will usually be confined to transoceanic trade, and to 

 cities and towns where the principal business of the 



z.r?, 



2407. Structural details of the bu 



E shown in Fie. 2406. 



2406. Apple storehouse in Vermont. 



refrigerating machinery will be the production of ice 

 for commercial and domestic use, the cold storage 

 warehouse being a side issue to ice-making. The 

 fruit-grower who wishes to avail himself of the ad- 

 vantages of cold storage must either ship his product 

 to the city or depend upon natural ice to reduce the 

 temperature of his warehouse. If he is in a climate 

 where a supply of natural ice is available, his most 

 economical plan is to make provision to use it. If in 

 the far South he must own an ice plant or purchase 

 artificial ice. 



To successfully handle peaches and plums in car- 

 lots, one must nowadays have a supply of ice in order 

 to avail oneself of the best service of the Fruit-Growers' 

 Express or other lines The cars come iced, it is true, 

 but before starting them on their journey it is safest for 

 the grower to have a sufficient supply of ice to fill the 

 pockets of the car 



To hold apples from harvest time until the over- 

 supply of the season shall have been removed, requires 

 storage rooms artificially cooled to a temperature suffi- 

 ciently low to check the process of ripening, which is 

 in reality the conversion of the starch of the imma- 

 ture fruit into sugar. As long as the starch remains 

 as such, fermentation and decay cannot 

 act, but as soon as sufficient water and 

 heat are added to convert the starch 

 into sugar, ripening proceeds until fer- 

 mentation and decay complete the work. 

 The object of cold storage, then, is to 

 eheck the ripening process, or, if the 

 fruit is ripe, to maintain a temperature 

 sufficiently low to check fermentation. 

 Theoretically, then, green or immature 

 fruits will keep better than ripe ones. 

 Green fruits should keep as well at 36° 

 as a ripe fruit at 32°, and this is in ac- 

 cord with experience. 



To successfully hold fruit in cold stor- 

 age, three conditions are essential: {1) 

 a low temperature; (2) an even tempera- 

 ture, and (3) sufficient moisture to pre- 

 vent shrinkage, thus keeping the fruits 

 plump and crisp. Even in storage 

 rooms in which the humidity of the air 

 remains saturated, as indicated by the 

 ordinary wet- and dry-bulb thermome- 

 ter, considerable loss of moisture will 

 take place from fruits stored in crates or 

 open bins, while much less is lost by 

 those stored in tight receptacles. Indi- 

 vidual Baldwin apples under observation 

 in a room at 32° F., from January 4 to 



