WARMING AND VENTILATION that are employed to exhaust apartments of vitiated air. An extra ventilating flue may be constructed adjoining the chimney, warmed by it, and opening into the top of the room, and this may have connecting tubes extending to remote, apartments for the ventilation of the whole house. But double outlets to the same apartment rarely work satisfactorily, as the chimney is apt to convert the extra flue into a feeder of the fire, while the smoke escaping from the chimney may be drawn down the flue into the room. The efficiency of ventiducts is augmented by surmounting them with ejectors, which increase their exhaustive action when the wind blows. But under ordinary circum- stances, or in the absence of other arrange- ments, the chimney may be used for convey- ing away foul air, the velocity of the ascending current giving it considerable exhaustive pow- er. If therefore an opening is made in the chimney breast near the ceiling, the foul gases accumulated in the upper part of the room rush in, and are carried upward with the cur- rent. Yet if from any cause the draught of the chimney be interrupted, smoke is driven back into the room ; an ordinary register, requiring personal attendance, being of little use. To remedy this inconvenience, Dr. Arnott con- structed a self-acting suspension valve, which is placed in the aperture, and so mounted that a current of air passing into the chimney opens it, while an opposite current closes it. A simple modification of this valve consists of a square piece of wire gauze set in the opening with a curtain of oiled silk suspended behind. Gas jets may be made important auxiliaries to ventilation. Inserted in the bottom of air shafts, they establish active currents which withdraw the vitiated air, and may be made especially useful on occasions when apartments are unusually crowded. It has been proved by experiment that 1 cub. ft. of illuminating gas can be utilized so as to cause the discharge of 1,000 cub. ft. of air; and as a common gas burner will consume nearly 3 ft. of gas an hour, it would extract from an apartment 3,000 cub. ft. of contaminated air during that period. By suitable contrivances also the gas lights, which are usually such active causes of deterioration, may not only become self -ven- tilating and carry off their own impurities, but also aid materially in keeping pure the air of inhabited apartments. Inventors have made successful contrivances for ventilating the burners of chandeliers, but they have hitherto not received the attention they merit. The point of entrance of fresh air into dwellings is a matter of importance too much neglected. If there be local sources of im- purity in the vicinity, or dust, or organic con- taminations near the ground, the apertures of ingress should be so placed as to avoid them. It may be well to bring the air from the top of the house. Openings are sometimes made under the eaves leading to channels constructed in the walls which open into the rooms, or WARNER 457 furnish air for the warming apparatus. The practical question in ventilation, at what points the fresh air should be introduced into an apartment and the foul air removed from it, is still a matter of controversy. But the points to be secured in regard to openings are, to place them so as to produce the most per- fect diffusion of fresh air without sensible draughts, and to have the places of egress as far away from the inlets as possible. Ob- viously, if there are large openings or registers of escape at the top of the room, and capa- cious inlets at the bottom, a strong current from the lower to the higher aperture would be established with imperfect diffusion. The best distribution is effected where the inlets and outlets are numerous, giving rise to many and moderate currents. The general require- ments of artificial ventilation are, that the heating arrangements adopted in dwellings shall be made subservient to the supply of pure air ; that definite and ample provision shall be made for the withdrawal of irrespira- ble air ; that equal provision shall be made for bringing in the pure air from without; and that the renewal of the breathing medium by this exchange shall be in relation to the capa- city of the apartment, while the details of the arrangements are conformed to the varying circumstances of dwellings, apartments, and occupancy. In its application to assembly rooms, legislative chambers, churches, hospi- tals, theatres, &c., the subject of warming and ventilation presents complicated and still un- settled problems of science and practice, which form a regular branch of technological study. See "A Manual of Practical Hygiene," by Edward A. Parkes, M. D. (4th ed., London, 1873) ; " A Handbook of Hygiene and Sani- tary Science," by George Wilson, M.D. (2d ed., London, 1873); and Gen. Arthur Morin's treatise " On Warming and Ventilation of Oc- cupied Buildings," translated from the French in the Smithsonian reports for 1873-'4. WARM SPRINGS, or Bath Court House, a post village and the capital of Bath co., Virginia, noted for its thermal springs, 130 m. W. N. W. of Richmond, and 15 m. N. W. of the Chesa- peake and Ohio railroad. The county contains numerous medicinal springs, known as Warm, Hot, Healing, and Alum Springs. The Warm Springs, most frequented by invalids, are in a narrow valley between two mountain ridges. The largest spring, 50 ft. in diameter, has a constant temperature of 98 F. The water holds in solution muriate, sulphate, and car- bonate of lime, and sulphate of magnesia. WARNER, Charles Dudley, an American author, born in Plainfield, Mass., Sept. 12, 1829. He graduated at Hamilton college in 1851, was connected with a surveying party on the Mis- souri frontier, studied law in New York, in 1856 was admitted to the bar in Philadelphia, and practised in Chicago till 1860. He then became assistant editor, and subsequently edi- tor of the Hartford (Conn.) "Press," and in
