210. The furnace known by the above appellation, is a modification of the White. The cylinder is lined with bricks in only one-third of its length from the lower end, adjoining the fireplace, the diameter of this portion of the iron shell being 10 inches greater than that of the unlined portion. The ore enters the cylinder at the upper and cooler end, and is lifted and showered by means of projections which in the unlined portion are formed of iron, in the lined portion of projecting bricks.

The inclination of the cylinder is fixed, the time occupied by the ore in passing through it being regulated by the number of rotations per minute, which is adjustable at will.

The length of the cylinder is 23 feet 2 inches. The internal diameter of the smaller part of the iron shell is from 22 to 50 inches, that of the enlarged portion being as stated 10 inches more, in order to admit of lining.

The working capacity of the furnace ranges from eight to forty-five tons of ore in 24 hours, according to the character of the ore and the diameter of the cylinder.