which the little craft was armed--two
eleven-inch rifled cannon, the invention of John Adolph Dahlgren.
Dahlgren had been connected with the ordnance department of the navy at
Washington for many years, and his inventions had revolutionized United
States gunnery.

Dahlgren was born at Philadelphia, where his father was Swedish consul,
a position which he held until his death in 1824. The boy, from his
earliest years, had been ambitious to enter the navy, and finally, at
the age of seventeen, received his midshipman's warrant. In 1847, he was
assigned to ordnance duty at Washington, and began that career of
extraordinary energy, which lasted for sixteen years. He saw almost at
once the many defects in the cannon which were at that time being
manufactured, and soon offered a design of his own, which proved a vast
advance over old guns. The Dahlgren gun, as it was called, was of iron,
cast solid, with a thick breech adjusted to meet varying pressure
strains. The invention of the rifled cannon followed, and it was this
weapon which caused even the great armored Merrimac to tremble. Admiral
Dahlgren's career was a distinguished one, but no service he rendered
his country was more noteworthy than this.

But there are triumphs of peace, as well as of war, and one of the most
notable of these was won by Cyrus Hall McCormick when he invented the
automatic reaper which bears his name. In 1859, it was estimated that
the reaper was worth $55,000,000 a year to the United States; William H.
Seward remarked that, "owing to Mr. McCormick's invention, the line of
civilization moves westward thirty miles each year"; and the London
Times declared, after it had been tested at the great international
exhibition of 1851, that it was "worth to the farmers of England the
whole cost of that exhibition." To few men is it given to confer such
benefits upon mankind, and the career of this one is well worth dwelling
upon.

Cyrus McCormick was born in 1809, in a little house at the hamlet of
Walnut Grove, Virginia. His father was a farmer, and was also something
of a mechanical genius, and as early as 1816, had tried to build a
mechanical reaper. His son inherited this aptitude, and helped his
father in mechanical experiments, soon quite outstripping him. As a
farmer's boy, his day's work in the fields began at five o'clock in the
morning, and in the harvesting season even earlier. But in the harvest
field, he found himself unable to keep up with