(1) Common ice made from filtered water without processing. (2) Raw water ice made from filtered or treated water, aerated or agitated, while freezing. (3) Distilled water ice made from condensed steam, reboiled. (4) Plate ice, made from raw water in large plates and cut up into blocks of convenient size. In the production of distilled water there are various methods which will not be treated upon here. For the icing of cars and for ordinary cooling purposes ice made by process No. 1 is amply good except, perhaps, if the water from which the ice is made should not be clear, it may be necessary to use a portion of the bottom of the cake for car icing purposes only. =Natural Ice.=--The situation and climate has much to do with the determination as to whether the packer can afford to harvest natural ice for general use. For example, if the plant be situated in a northern climate alongside a suitable stream adjacent to the plant, the harvesting of ice and its storage can be afforded. However, if the ice is stored at a remote point and teaming or car shipment of ice is necessary, then the manufacturing plant will probably be the more economical. =Chilling.=--The chilling of the meat immediately after killing is perhaps the most important function in the whole refrigerating process and one that cannot have too much attention. In the matter of beef it is the practice of the best operators to see to it that immediately after the hide is removed the beef is placed in the coolers. At most it should not be allowed to stand out in the open air to exceed half an hour. Sheep and veal should be treated in the same manner. As for hogs in some climates, such as latitude equal to Chicago or north thereof, if space is available an open air hanging room is a valuable adjunct where the animal can be air dried, depending upon seasons, from one hour to over night. This feature also permits of increased slaughtering during the winter season. It is a custom that can be abused, however, by careless handling--resulting in sour meats. =Quantity of Refrigeration to Provide.=--There are so many factors which enter into the question of packing house refrigeration, and so many details of construction and application of refrigerating apparatus, that it is almost impossible to cover this subject practically and intelligibly without devoting a volume to refrigeration alone.