working day.  Two of the mills were horizontal granite burrs more than four feet in diameter, the upper one revolving once with each circuit made by the cow.  The third mill was a pair of massive granite rollers, each five feet in diameter and two feet thick, joined on a very short horizontal axle which revolved on a circular stone plate about a vertical axis once with each circuit of the buffalo.  Two men tended the three mills.  After the cotton seed had been twice passed through the mills it was steamed to render the oil fluid and more readily expressed.  The steamer consisted of two covered wooden hoops not unlike that seen in Fig. 77, provided with screen bottoms, and in these the meal was placed over openings in the top of an iron kettle of boiling water from which the steam was forced through the charge of meal.  Each charge was weighed in a scoop balanced on the arm of a bamboo scale, thus securing a uniform weight for the cakes.

On the ground in front of the furnace sat a boy of twelve years steadily feeding rice chaff into the fire with his left hand at the rate of about thirty charges per minute, while with his right hand, and in perfect rhythm, he drew back and forth the long plunger of a rectangular box bellows, maintaining a forced draft for the fire.  At intervals the man who was bringing fuel fed into the furnace a bundle of rice straw, thus giving the boy’s left arm a moment’s respite.  When the steaming has rendered the oil sufficiently fluid the meal is transferred, hot, to ten-inch hoops two inches deep, made of braided bamboo strands, and is deftly tramped with the bare feet, while hot, the operator steadying himself by a pair of hand bars.  After a stack of sixteen hoops, divided by a slight sifting of chaff or short straw to separate the cakes, had been completed these were taken to one of four pressmen, who were kept busy in expressing the oil.

The presses consisted of two parallel timbers framed together, long enough to receive the sixteen hoops on edge above a gap between them.  These cheeses of meal are subjected to an enormous pressure secured by means of three parallel lines of wedges forced against the follower each by an iron-bound master wedge, driven home with a heavy beetle weighing some twenty-five or thirty pounds.  The lines of wedges were tightened in succession, the loosened line receiving an additional wedge to take up the slack after drawing back the master wedge, which was then driven home.  To keep good the supply of wedges which are often crushed under the pressure a second boy, older than the one at the furnace, was working on the floor, shaping new ones, the broken wedges and the chips going to the furnace for fuel.

By this very simple, readily constructed and inexpensive mechanism enormous pressures were secured and when the operator had obtained the desired compression he lighted his pipe and sat down to smoke until the oil ceased dripping into the pit sunk in the floor beneath the press.  In this interval the next series of cakes went to another press and the work thus kept up during the day.