A strong current of hot air is drawn through the sweater by a powerful fan connected to the upper end by a very large pipe. The air introduced in this way is brought to a high temperature by passing around a number of coils of pipe charged with steam, which are placed directly in front of the sweater. The hot air sweeping through the drum absorbs nearly all of the moisture in the sugar, which carries 1.2 per cent of water when it enters the drum and about 0.1 per cent as it leaves it. The granulator, or lower drum, is the same size as the sweater and is constructed in very much the same manner, having shelves for carrying the sugar to the top and dropping it at the proper point, and being equipped with a large fan to draw off the hot, moist air. Instead of having steam coils in front, however, it has in its center a steam-heated drum about twenty-four inches in diameter that revolves with it. The sugar crystals, as they fall in a shower from the shelves, come in contact with the hot inner drum on their way through the granulator, and in this manner become thoroughly dried. The moisture in the sugar, as it emerges from the granulator, is less than four-hundredths of one per cent, an amount too slight to determine except with the most delicate apparatus. [Illustration: FRONT VIEW OF SWEATER—SHOWING STEAM COILS FOR HEATING THE AIR] [Illustration: INTERIOR VIEW OF SWEATER] To insure perfect drying, the damp sugar must be fed to the upper drum or sweater with unfailing regularity. This is accomplished by the use of revolving screws located under the storage bins. By turning a certain number of revolutions per minute, they deliver an even and steady supply of sugar. From the granulators the sugar is dropped on thin cotton belts that, passing around highly magnetized pulleys, carry it to the dry storage bins. The sugar is cooled to normal temperature before being packed in containers, thus preventing subsequent absorption of moisture and consequent caking. Magnetic pulleys are used to extract any particles of iron scale or rust that may drop into the sugar after the liquor leaves the char filters. Rust sometimes forms in the pans, mixers, conveyors, elevators, sweaters or granulators, and should it get into the sugar the magnetic pulleys will surely remove it. Storage bins and storage tanks are prominent accessories of all sugar refineries, for if a breakdown should occur at any point, there must always be a supply of material on hand to keep the refining operations going while the trouble is being remedied. SCREENING SEPARATING CRYSTALS INTO VARIOUS SIZES