There are four washers and four dryers in the laundry room.
The manufacture of springs, valves and washers does not require any very special notice, these articles being generally fashioned out of mixed rubber, and vulcanized either in moulds or in powdered French chalk.
The kilns are closed at the top, and the gases are drawn out by powerful air-pumps, washers being interposed be,, veen the kilns and the pumps for the purpose of purifying and cooling the gas.
Every winter the supply is exhausted by the washers, and every summer it is renewed by the river.
The solubility of naphthalene by various oils has led some engineers to put in naphthalene washers, in which gas is brought into contact with a heavy tar oil or certain fractions distilled from it, the latter being previously mixed with some volatile hydrocarbon to replace in the gas those illuminating vapours which the oil dissolves out; and by fractional distillation of the washing oil the naphthalene and volatile hydrocarbons are afterwards recovered.