Page:The New International Encyclopædia 1st ed. v. 15.djvu/618

PENNSYLVANIA. colonies, it was spoken of as ‘most advanced’ in Pennsylvania as early as 1756. In 1900 it furnished 54 per cent. of the total product for the United States. The localization of the industry is determined by the accessibility to ore and fuel, and consequently until about 1850 the industry was most extensive in the eastern anthracite coal and iron ore district. (Charcoal, however, had been universally used prior to 1840.) Since then the Pittsburg district, in the western part, has far surpassed the eastern district. This change is coincident with the substitution of bituminous coal and coke and natural gas for anthracite coal, and with the development of the Lake Superior ore region. The pig iron produced in 1900 by the use of bituminous coal and coke amounted to 76 per cent. of the total for

the State. The ore used in this part of the State comes from the Lake Superior district, having the advantage of cheap water transportation. From 1890 to 1900 the increase in iron and steel was 64.2 per cent. Although the industry is largely centered in the towns of Allegheny County, it is important in almost every large town. The manufacture of Bessemer steel began in 1867. Within the last two decades, however, the Bessemer process has been largely supplanted by the open-hearth process.

In foundry and machine-shop products the State ranks first. For instance, it made in 1900 more than one-half the total number of steam locomotives made in the United States. Since 1845 locomotives of Pennsylvania make have been shipped in constantly increasing numbers