that cut sheets of iron as a lady's scissors cut paper. This cut the
squares of metal used for boiler plates, and the steam-engine having
come, was turned to the manufacture of materials for its own
construction. Others were able to bite off great bars.

The first mill in which iron was rolled in America, was built in 1817
near Connellsville, in Fayette county, Penn. Until 1844, the rolling
mills of this country produced little more than bar-iron, hoops, and
plates. All the early attempts at railroads used the "strap" rail;
unless cast "fish-bellies" were used; which was flat bar-iron provided
with counter sunk holes, in which to drive nails for holding the iron to
long stringers of wood laid upon ties. When actual rail-making for
railroads began, the rolling mill raised its powers to meet the
emergency. The "T" rail, universally now used, was invented by Robert
Stevens, president and chief engineer of the Camden and Amboy railroad,
and the first of them were laid as track for that road in 1832. From
this time until 1850, rolling mills for making "U" and "T" rails rapidly
increased in number, but in that year all but two had ceased to be
operated because of foreign competition.

[Illustration: SHEARS FOR CUTTING BAR-IRON.]

During some five years previous to this writing a revolution has taken
place in the construction of buildings which has resulted in what is
known as the "sky-scraper." This was, in many respects, the most
startling innovation of times that are startling in most other respects,
and was begun in that metropolis of surprises and successes, the city of
Chicago. This innovation was really such in the matter of using steel in
the entire framing of a commercial building, but it was not the first
use of metal as a building material. The first iron beams used in