ANIMAL PRODUCTS 



this granular condition lowered the mar- 

 ket price of the cheese. 



Refrigeration on vessels — There re- 

 main for consideration some of the other 

 commercial uses of refrigeration of ani- 

 mal food products. On meat transport 

 vessels actual freezing is usually resorted 

 to in order to make sure that decom- 

 position is prevented as far as possible. 

 Australia exports about 7,000,000 frozen 

 rabbits annually. Some of the meat 

 transport steamers plying between Aus- 

 tralia and England are fitted with freez- 

 ing rooms in which the carcasses of 4,000 

 cattle and 14,000 sheep can be stored. 

 When frozen meat .is thawed out the 

 juices run out of the cut surfaces read- 

 ily, it keeps but a short time, and its 

 flavor is imfavorably affected. On long 

 transoceanic trips and in provisioning 

 garrisons it may be necessary to freeze 

 the meat despite the disadvantages of 

 the process. Millions of pounds of frozen 

 beef and mutton have been shipped 

 to the Philippines. Fish have been 

 frozen and skipped in a frozen condition 

 for the last 30 years. Fish meat seems 

 not to take much harm from freezing. 



Construction of cold storage houses — 

 We may now mention briefly some of 

 the points to be observed in the materials 

 and methods of construction of cold 

 storage rooms. The requirements re- 

 garding temperature, circulation of air, 

 humidity and absorbents have been men- 

 tioned above in connection with a discus- 

 sion of the various animal products in 

 cold storage. 



Insulation — Another very important 

 feature of the internal construction of 

 cold storage rooms is insulation. Besides 

 being a non-conductor of heat the insu- 

 lating material should be non-odorous, 

 should not absorb moisture, should be 

 vermin proof, fireproof, inexpensive, 

 durable and air-tight. Cold storage 

 operators have found that the best insu- 

 lation is the cheapest in the end. Some 

 loss of heat occurs despite all efforts, but 

 it is economy to reduce this loss to a 

 minimum by making a sufficient outlay 

 for good insulation at the start. Light- 

 foot recommends an outer and inner 

 layer of tongued and grooved boards 1 

 or iy 2 inch in thickness, separated by a 

 9-inch space which is filled with char- 

 coal, silicated cotton or slag wool. 



In France and Germany, ground cork 

 is much used for this purpose, and in 

 New Zealand and Australia, pumice 

 stone. Among the large number of 



other materials which have been used, 

 Taylor mentions asbestos, cotton wool, 

 sheep's wool, pine wood, loam, ashes, 

 sawdust, hairfelt, lampblack, mica, paper, 

 .pitch, etc. Various proprietary com- 

 pounds have also been manufactured 

 for this special purpose. The packing 

 in the space between the two walls must 

 not only be a non-conductor but must 

 not absorb moisture. In these respects 

 cork is very desirable, as is also lamp- 

 black, pitch and mica. Cork and lamp- 

 black possess the advantage of lightness 

 and elasticity. Air inclosed with the in- 

 sulating material between the walls helps 

 in preventing the heat from leaking in. 

 The amount of heat transmitted by dif- 

 ferent substances varies greatly. Thus, 

 copper conducts 2,000 times as much 

 heat as blotting paper, iron 800, stone 

 56, glass 25, brickwork 17, cork four 

 times as much and cotton about the same 

 amount as the blotting paper. In con- 

 structing an ice house and cooling room 

 it is obviously necessary to give due 

 heed to these points. Dry air is a very 

 poor conductor of heat. Dead air spaces 

 are therefore effective in preventing the 

 penetration of heat from the outside. 



Good insulation implies that the walls 

 are waterproof. For this purpose, Stod- 

 dard tested a large variety of paints, oils, 

 varnishes, cements and waterproof coat- 

 ings. Resins, gums and oils were found 

 to be of no practical use. Pitch and 

 asphaltum proved objectionable on ac- 

 count of their odor. The best results 

 were obtained from the use of Bay State 

 Air and Waterproofing, Red Mineral 

 paint, Spar varnish, Portland cement, 

 hot paraffine, water paint, etc. From 

 two to four coats are required. Doors 

 must be constructed like the walls so 

 that heat cannot penetrate and so that 

 they will not frost through in zero 

 weather. Windows can be dispensed 

 with in a cooling room, or if present 

 should consist of three sashes with dead 

 air spaces between them. 



Cold storage on the farm — I n the 

 above account of refrigeration we have 

 discussed chiefly cold storage on a com- 

 mercial scale. The farmer may also 

 wish to have an ice house and cooling 

 room. In the following pargraphs sug- 

 gestions are made regarding cold storage 

 on the farm and the relation of cold 

 storage in general to the farmer. 



In all cases, it is best to have the whole 

 structure above ground and the ice room 

 above the cooling room. The ventila- 

 tion of the cooling room can then be 



