Thereafter the census placed together the manufacturers of stoves, furnaces, and gas and oil stoves, and the total annual value of the products is over $75,000,000.
Oil and Gas Oil stoves for do mestic use became common about 1875. The earlier types were simply large lamps, burning kerosene, and having a fixture on top for sup porting a pan, kettle or cooking or heating utensil. Very broad wicks were employed, and a circular burner and wick were also intro duced, that gave good results. These oil lamps or oil stoves had to be kept very clean to secure good combustion, as they delivered a great deal of carbon, which tended to clog the mechanism. It was a decided improvement when the vapor burning stove was later introduced. In this the naphtha or other light product of pe troleum was stored in a small metal tank, and led through a pipe to one or more burners— usually a set of burners, arranged like the top of a stove. The aperture to the burner was very small, and the slight stream of naphtha that flowed was easily vaporized, so that after a burner had been lit a minute or less, it ceased to burn oil directly as the pipe near the burner became hot enough to vaporize the oil, and delivered vapor to the burner. This vapor could be mixed with air, on the principle of a Bunsen burner, and thus the consumption of fuel was both economical and safe, for the tank was at a distance from the flame. Oil stoves of a variety of types, utilizing the prin ciples here described, are on the market, and are not only an economical method of heating, but very convenient as to portability. They have the disadvantage, however, of rapidly consuming the oxygen in a small room, and constant ventilation is required to render the air fit to breathe.
Gas stoves have been made and used for a long time, but were never popular until after the general agitation for lower-priced gas had resulted in bringing ordinary illuminating gas resulted in bringing illuminating gas to a price below $1.50 per 1,000 cubic feet. An exception region of the Middle West where they first came into common use in the 60's and 70's. About 1890 the gas companies of the United States began a concerted effort to introduce gas stoves to increase the sale of their com modity. The common type of heating stove offered was of the radiator type, with a row of burners in the base, and large metal tubes directing the heat toward the top, so as to afford plenty of radiating surface. These were
made of sheet iron, usually ornamented with nickel, in various sizes, and they have become common for household use, where rooms are not heated by furnace or steam. For cooking purposes, the gas companies have supplied gas ranges, patterned after the coal ranges on top, and as to oven conveniences. Rosette burners are placed where the uholesp are in a coal range, and mixers employed to admit air to the burners, so as to secure hot blue flames, with a minimum consumption of gas. These gas ranges have become very popular with housewives, for they save the dirt and dust of coal and ashes, involve cost only when in actual use and are easily lit and turned out. They are often used in summer time along side coal ranges, which are allowed to lie idle, the reason being that the gas range creates less heat in the room, and is, therefore, more com fortable. Despite the fact that gas fuel gen erally costs considerably more than coal, the conveniences of the gas stove and gas range have resulted in a steadily increasing use.
The first hot-air furnace for supplying pure heated air to rooms was prob ably that constructed by Franklin in 1744. This was a sheet-iron oblong box, burning wood, the smoke passing into the chimney over the top of the flat chamber behind the fire, and between it and the real back of the stove. The cool air entered this flat hollow chamber through a pipe, and when heated passed through small holes in the side of the chamber into the room. This style of ap paratus was not much improved upon till the beginning of the 19th century when in 1808 Daniel Pettibone of Philadelphia took out a pipe, and usually have but one damper com bined with the cold-air check. In the cheaper styles of direct-draft furnaces, this radiator is done away with, the gas passing directly into the smoke-pipe, but this system wastes much heat that is utilized by the better grade of fur nace. In the indirect draft type of furnaces the radiator is located near the base and the gases pass down through flues to it, thence up ward and through another flue to the pipe. This style of furnace has a direct-draft damper in addition to the damper in the pipe, thus allowing the gas to escape to the chimney more easily.