Returning to the sugar left in the centrifugals, the force developed in a machine forty inches in diameter, spinning at the rate of eleven hundred revolutions per minute, is so great that it quickly dispels all the liquor surrounding the crystals, leaving them nearly dry, in a solid, vertical wall. Water, filtered to insure its purity and cleanliness, is then sprayed on this spinning wall of sugar, only to be immediately thrown off through the sugar by the centrifugal motion. In passing through the sugar it washes the last of the syrup from the grains and leaves them perfectly white. Cold water, rather than hot, is used for this purpose, as it dissolves less sugar. In former years a small quantity of bluing was added to the spraying water in order to enhance the whiteness of the sugar, just as bluing is employed in washing fine linen fabrics. Since the pure-food laws became effective, however, the practice has been discontinued in all cane-sugar refineries. After the sugar is thoroughly washed, the centrifugal machine is stopped, a large valve in the bottom opened and the mechanical discharger rapidly ejects the sugar (now containing only about 1.2 per cent moisture) from the machine into a storage bin beneath. FINAL DRYING OF CRYSTALS For some reason not well understood, the next step in refining is called “granulation.” Actual granulation, or crystallization, takes place in the pans, and the process about to be described should properly be called drying. The manufacturing term, however, is as given. Drying is effected in an apparatus consisting of two large cylindrical drums of wrought iron. These drums are about six feet in diameter, thirty feet long and have a slight downward pitch from the receiving to the discharging end. The first drum rests on the floor, directly below the storage bin, and is called the sweater. It turns slowly on revolving wheels, by means of circular tracks bolted to it. The power that moves it is delivered from an electric motor, through a pulley, shaft and pinion, the latter working in a gear bolted to the outside circumference of the drum. Fastened to the inner surface of this drum is a series of short, narrow shelves with saw-tooth edges that serve to carry the sugar to the top of the revolving cylinder, whence it falls to the lower side, causing a continual shower of sugar throughout the entire length and breadth of the drum. The sugar is delivered through a pipe at the upper end of the sweater, and the revolving motion together with the incline of the cylinder gradually works it down to the lower end. Here it drops through a chute to the granulator on the floor below, where the process of drying is completed.