same year by a heating furnace at the works of the Nashua Iron and Steel Company, Nashua, N. H., and early in 1868 the first "Siemens furnace" for melting steel in crucibles (often called a "pot furnace") was started in the works of Anderson & Woods at Pittsburgh.
The first works in which the "Siemens gas furnaces" were used, to the exclusion of all other methods of burning fuel, were those of the American Silver Steel Company, at Bridgeport, Conn., which were erected from the plans and under the supervision of the author of these papers in 1868-'69. In these works were two puddling furnaces, three heating furnaces, one twenty-four-pot melting furnace, a twenty-four-pot muffle, and ten "gas-producers," all on the Siemens principle. Gas from the "producers" was used under the boilers with entire success. At the time of the erection of these works they were the largest and most perfect plant of gas furnaces in America.
"Natural gas" has been known to the nations of the Old World for thousands of years. The Persian fire-worshipers used it for their sacred fire, and it has been used as a fuel in China since a time beyond the range of authentic history.
The earliest use of natural gas in this country was as an illuminant in the village of Fredonia, N. Y., in 1827, and it is still used there. The first person to use natural gas for manufacturing purposes is believed to have been Mr. William Tompkins, who, in 1842, employed it in the Kanawha Valley for heating the kettles of a "salt-block" one hundred feet in length. In 1845 Messrs. Dickerson and Shrewsbury bored a well on the Kanawha River, in West Virginia, to a depth of one thousand feet, from which a sufficient quantity of gas issued, according to a computation by Prof. B. Silliman, Jr., "to light the city of New York for twelve years." The first use of natural gas for the manufacture of iron was in the Siberian Rolling-Mill of Rogers & Burchfield, at Leechburg, Armstrong County, Pennsylvania, in 1874; twenty-nine years after it had been successfully used under a "salt-block" in West Virginia, and forty-seven years after its first use for light-
- All these furnaces, and many subsequently constructed, were built from the plans of J. Thorpe Potts, an English engineer, who was one of the firm of Richmond & Potts, representatives of the inventors in this country.
- These furnaces were the first successful gas puddling furnaces constructed, and although their performance was in every way satisfactory, and the works were visited by every prominent iron manufacturer in America, it was many years before puddling with gas became popular with the iron-masters of the country; in fact, it was not until the introduction of "natural gas" that the great value of gaseous fuel began to be properly appreciated, and even now there are new works for the manufacture of iron being erected, in which the puddling furnaces are not in any way better than those in common use in 1840.
structed for melting glass. None of these furnaces were built from the inventors' plans or under their license, and all were abandoned after a short life.