Page:Popular Science Monthly Volume 40.djvu/49

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39
AMERICAN INDUSTRIES SINCE COLUMBUS.

cover some means by whicli pig iron high in phosphorus could be used m 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 "open- hearth 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 num- ber of claimants, English, French, and American, for the discov- ery 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 great- ly the use of the "basic process" in this country; but, never- theless, there were made during the year 1890 about ninety thou- sand tons of " basic steel " in the United States. The " basic pro- cess" IS very largely employed in Europe, and fairly deserves recognition as the most important improvement in the metal- lurgy of steel that has been practically developed within the past dozen years.

In recent years there have been a number of alleged improve- ments m the manufacture of steel patented, most of them havino- no value. ^

It will be remembered that some of the early American experi- menters, 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 mak- ing 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'coun- try m the world.

. .T'^??*^'^^-^ y®^^^ ^^o ^l^ere were but two Bessemer converters m the United States, and it is not at all probable that in the year 18(Jo there were more than five hundred tons of "Bessemer steel" made therein; but this germ product has so wonderfully devel- oped that m the year 3 890 the total production of "Bessemer steel m this country was 4,131,535 net tons, or 8,263 times the

th.?' 'f T- ^'" •' ^ *^'* " " "'^' P™^*^^^ " ""^ <^ond"Cted in Europe involves the use o the invention of Messrs. Thomas and Gilchrist, in connection with those of G. J. Snelus of Workm^ton, and Edward Riley, of London, whose inventions have contributed

materially to its success.