believing that a motive power
developed from materials of small weight was essential to the solution
of the problem, resolved to employ the explosive force of chloride of
nitrogen,--one of the most dangerous compounds known to chemists. The
result of his experiments in this direction was an explosion which blew
his apparatus to pieces, and nearly cost the audacious inventor an eye.
In fact, though the organ was saved from total destruction, it was
permanently injured.

The conveyance of freight by aerial cables--a method now widely
used--was practiced by Mr. Cooper at an early day. The use of elevators
in buildings was foreseen and provided for by him in the erection of the
Cooper Union building, and in that building also he introduced for the
first time iron beams as part of a fire-proof construction. In these and
other inventions his prophetic intuitions were illustrated.

But such intuitions do not fully take the place of scientific training;
and one of the inventions of Peter Cooper--which he considered for many
years, and possibly to the very last, as his crowning achievement--was a
curious example of misdirected ingenuity. It is worthy of notice here,
however, for another reason, namely, because of its accidental
association with one of its inventor's most remarkable triumphs.

As a young apprentice he had studied the steam engine, and had resolved
that he would improve it by doing away with the crank. To his mind this
was a source of great loss of power, and he believed that, if he could
transform the rectilinear motion of the piston rod directly into rotary
motion without the intervention of the crank, he would effect a notable
economy.

Now, there is no such loss of power through the crank as he imagined,
nor is it likely that any other device for obtaining rotary from
rectilinear motion will be found superior to that which Watt devised.
But Peter Cooper assailed this fancied evil with undoubting confidence,
both as to its existence and as to his ability to do away with it. The
result was an invention for which he received, April 28, 1828, letters
patent of the United States. At that early day patents were
comparatively few,--so few that this one bears no number; and the duties
of general administration did not prevent the highest officials from
attending to details. This patent, issued to Peter Cooper, of New York,
was personally signed by John Quincy Adams, President; countersigned by
Henry Clay, Secreta