milk—that is, the watery—crowd towards the point furthest from the centre, and keep the lighter fatty elements away from contact with the sides of the drum. In the diagram the water is represented by small circles, the cream by small crosses.
As more milk enters the drum it forces upwards what is already there. The cap of the drum has an inner jacket, F, which at the bottom all but touches the side of the drum. The distance between them is the merest slit; but the cream is deflected up outside F into space E, and escapes through a hole one-sixteenth of an inch in diameter perforating the plate G. The cream is flung into space K and trickles out of spout B, while the water flies into space H and trickles away through spout A.
THE "HYDRO.,"
used in laundries for wringing clothes by centrifugal force, has a solid outer casing and an inner perforated cylindrical cage, revolved at high speed by a vertical shaft. The wet clothes are placed in the cage, and the machine is started. The water escapes through the perforations and runs down the side of the casing to a drain. After a few minutes the clothes are dry enough for ironing. So great is the centrifugal force that they are consolidated against the sides of the cage, and care is needed in their removal.
Chapter XIX.
HEATING AND LIGHTING.
The hot-water supply—The tank system—The cylinder system—How a lamp works—Gas and gasworks—Automatic stoking—A gas governor—The gas meter—Incandescent gas lighting.
HOT-WATER SUPPLY.
A well-equipped house is nowadays expected to contain efficient apparatus for supplying plenty of hot water at all hours of the day. There is little romance about the kitchen boiler and the pipes which the plumber and his satellites have sometimes to inspect