Packings for glands, &c., are made of cotton, hemp, and other fibres, asbestos, indiarubber, &c., in round, square, and other sections.
Section 100.—HEATING APPARATUS.
For general purposes this comprises Furnaces, Stoves, Ranges, Ovens, Boilers (see [Section 6]), Hot-blast, Steam-heated Vessels, Gas Jets, &c., most of which are tolerably well known and in common use.
For special purposes in connection with machinery various heating devices are required, of which steam and gas are those most universally used. Steam tubes or coils may be carried through any fixed or movable part of a machine. Steam-heated surfaces, such as tables, pans, chambers, &c., steam-jacketed cylinders, and similar contrivances, are much used. Gas jets from perforated tubes, which may be shaped to any required position, are also convenient for dry heat and higher temperatures than can be obtained from steam.
Hot irons are sometimes used, shaped to fit a cavity, but of course require to be replaced periodically.
Hot water in pipes or jackets, and hot air in flues are common appliances for warming and drying; with the former its circulation must be provided for, and with the latter, either a forced draught or an upward inclination given to the flues to maintain circulation.
[1876]. Gill pipes for radiating the beat of steam or hot water.
[1877]. Gill stove, on similar principle, presents an extensive surface in contact with the air for radiation of heat.