Page:Popular Science Monthly Volume 40.djvu/49

Rh some means by which pig iron high in phosphorus could be used in the "converter" or "open-hearth" furnace. Success was finally achieved in this by two English chemists, Sidney Gilchrist Thomas and Percy C. Gilchrist, of London, who secured patents for their invention November 22, 1877. Their modification of the "Bessemer process" consists in the employment of lime as the chief constituent of the lining of the "converter" or "openhearth furnace," and the action of this "basic lining" (hence the process is commonly called the "basic process") is to remove the phosphorus from the metal as a "phosphate of lime" in which condition it is found in the "slag" produced. There are a number of claimants, English, French, and American, for the discovery of the value of lime as a lining in "Bessemer converters" and "open-hearth furnaces" for the treatment of iron rich in phosphorus, who have caused so much litigation as to retard greatly the use of the "basic process" in this country; but, nevertheless, there were made during the year 1890 about ninety thousand tons of "basic steel" in the United States. The "basic process" is very largely employed in Europe, and fairly deserves recognition as the most important improvement in the metallurgy of steel that has been practically developed within the past dozen years.

In recent years there have been a number of alleged improvements m the manufacture of steel patented, most of them having no value.

It will be remembered that some of the early American experimenters, who "with great pains and cost found out and obtained a curious art by which to convert, change, or transmute common iron into steel" (in Connecticut, 1728 to 1750), succeeded in making somewhat more than half a ton of steel" in four years This seed of the steel industry on this continent has year by year and generation after generation increased and multiplied until for the year 1890 the production of steel of all kinds in the United States reached the enormous total of "4,277,071 gross tons" an amount larger than was produced in that year by any other country in the world.

Twenty-six years ago there were but two Bessemer converters in the United States, and it is not at all probable that in the year 1865 there were more than five hundred tons of "Bessemer steel" made therein; but this germ product has so wonderfully developed that in the year 1890 the total production of "Bessemer steel" in this country was 4,131,535 net tons, or 8,263 times the