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THE GROWTH OF THE STEAM ENGINE.
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scribed, in a work published at Rome, a number of ingenious mechanical contrivances, among which was a steam-engine (Fig. 5), in which the steam, issuing from a boiler, impinged upon the vanes of an horizontal wheel.
This it was proposed to apply to many useful purposes.
Fig. 4.—De Caus's Apparatus, a. d. 1615.
12. In illustration of the singular manner in which old inventions disappear only to reappear in latter times, it may be remarked that this contrivance was brought forward quite recently by a sanguine inventor, who spent a considerable sum in building what he considered a great improvement upon existing forms of steam-engines.
The engine of Hero also has been frequently reinvented, and, un-
