also carried forward. The original idea of this pneumatic railway
was derived from the contrivance of an American, quite unknown to fame,
who, as his sign expressed it, showed to visitors a new mode of carrying
the mail,[4] more simple, and quite as valuable, practically, as this
atmospheric railway. The submerged propeller of Ericsson, and the
submerged paddle wheel, the rival experiments of our two distinguished
naval officers, Stockton and Hunter, are now candidates for public
favor; and the Princeton on the ocean, as she moves in noiseless
majesty, at a speed never before attained at sea, seems to attest the
value of one of these experiments, while the other is yet to be
determined. The impenetrable iron steam vessel of Mr. Stevens is not yet
completed, nor have those terrific engines of war, his explosive shells,
yet been brought to the test of actual conflict.

In curious and useful mechanical inventions, our countrymen are
unsurpassed, and a visit to our new and beautiful Patent Office will
convince the close observer that the inventive genius of America never
was more active than at the present moment. The machines for working up
cotton, hemp, and wool, from their most crude state to the finest and
most useful fabrics, have all been improved among us. The cotton gin of
Eli Whitney has altered the destinies of one third of our country, and
doubled the exports of the Union. The ingenious improvements for
imitating medals, by parallel lines upon a plain surface, which, by the
distances between them, give all the effects of light and shade that
belong to a raised or depressed surface, invented by Gobrecht and
perfected by Spencer, has been rendered entirely automatic by Saxton, so
that it not only rules its lines at proper distances and of suitable
lengths, but when its work is done it stops. In hydraulics, we have
succeeded well; and the great aqueduct over the Potomac at Georgetown,
constructed by Major Turnbull, of the Topographical Corps, exhibits new
contrivances, in overcoming obstacles never heretofore encountered in
similar projects, and has been pronounced in Europe one of the most
skilful works of the age.

The abstract mathematics does not seem so well suited to the genius of
our countrymen as its application to other sciences. Those among us who
have most successfully pursued the pure mathematics, are chiefly our
much-esteemed adopted citizens, such as Nulty, Adrain, Bonnycastle,
Gill, and Hassler. Bow