Tallow

—A substance composed of the harder and le fusible fats, obtained by rendering beef or mutton fat, as also almost any of the animal fats, and of certain vegetable fats. Inferior kinds of animal tallow are known as “melted stuff,” “rough stuff” and “town tallow.” These are used in machinist’s work for coating bright work to prevent corrosion. In lubrication, tallow should not be used unle of the very best quality, since with high pre ure steam it becomes partially converted into oleic or stearic acids, which corrode the iron in the piston cylinders and steam joints.