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.
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Fig. 77.—Appliance for steaming tea leaves, used in Japan and the same in principle as used in China for steaming meal from which oil is to be expressed.
On the ground in front of the furnace sat a boy of
