pressure of business at the close of the session.

But notwithstanding the surprise and admiration which this achievement
excited in the scientific world, the speed attained was not sufficient
to meet the practical exigencies of commerce; and the repetition of
the engines on this large scale could not be undertaken at the charge
of individuals. Ericsson accordingly wisely devoted himself to
perfecting the Calorie-Engine on a small scale, and in 1859 he
produced it in a form which has since proved a complete success. It is
no longer a subject of experiment, but exists as a perfect, practical
machine. More than five hundred of these engines, with cylinders
varying from a diameter of six inches to one of forty inches, are now
in successful operation. It is applied to purposes of pumping,
printing, hoisting, grinding, sawing, turning light machinery, working
telegraphic instruments and sewing-machines, and propelling boats. No
less than forty daily papers (among which we may mention the "National
Intelligencer") are printed by means of this engine. In Cuba it is
used for grinding sugar-cane, on Southern plantations for ginning
cotton; and there is an endless variety of domestic, agricultural, and
mechanical uses to which it may be advantageously applied.

The extent of power attainable by this machine, consistently with its
application to practical uses, is not yet precisely defined. Within
the limit thus far given to it, its power is certain, uniform, and
entirely sufficient. It is not attended with the numerous perils that
make the steam-engine so uncomfortable a servant, but is absolutely
free from danger. It requires no engineering supervision. It consumes a
very small amount of fuel (about one-third of the amount required by
the steam-engine) and requires no water. These peculiarities not only
make it a very desirable substitute for the steam-engine, but render