The history of the first locomotives in America. From original ...

FIEST HEAD OF STEAM. 31^
impossible, yet they have been realized by modem in-
ventors. In all his projects, the expansive power of
steam alone was used.
That the steam-engine was not a mere theory in the
conception of Worcester, but was actually put into opera-
tion, a recent discovery has settled upon positive testimony.
The Grrand-duke of Tuscany, Cosmo de Medicis,
travelled in England in 1656. The manuscript of his
travels remained unpublished until 1818. The follow-
ing is an extract : " His highness," that he might not
lose the day uselessly, " went again, after dinner, to the
other side of the city, as far as Vauxhall, to see a
machine, invented by my Lord Somerset, Marquis of
"Worcester. It raises water more than forty geometrical
feet, by the power of one man only." Here, then, is a
description of an engine in actual operation.
In all these projects the expansive power of steam
was alone used ; the steam was made to act directly upon
the surface of the water ; in this way the use of high
steam is essential to success, and upon a large scale was
attended with danger in the low state of the mechanic
arts in those days, and various contrivances and im-
provements were introduced as in modern times. Con-
sequently their necessity became visible, and as early as
in 1680 the safety-valve, which has since been of such
importance in the construction of steam-engines, was
invented by Denys Pepin, a French Protestant. It was
made in the following manner : A conical aperture was
made in the lid or top of the boiler, and to this was fit-
ted a conical stopper, pressed into the aperture by a
weight suspended at the end of a lever. It was iden-
ticg,l with the most usual form of safety-valves at the
present day.
It has often been written that the power of steam
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