lecture on the subject in London, in the spacious theatre of the Royal
Institution. The novelty of the invention, combined with the
reputation of the lecturer, had attracted a very large audience,
including many individuals of eminent scientific attainments. Just
half an hour, however, before he was expected to enlighten this
distinguished assembly, the celebrated lecturer discovered that he had
mistaken the expansive principle which is the very life of the
machine. Although he had spent many hours in studying the
Caloric-Engine in actual operation, and in testing its absolute force
by repeated experiments, Professor Faraday was compelled to inform his
hearers, at the very outset, that he did not know why the engine worked
at all. He was obliged to confine himself, therefore, to the
explanation of the Regenerator, and the process by which the heat is
continually returned to the cylinder, and re-employed in the
production of force. To this part of the invention he rendered ample
justice, and explained it in that felicitous style to which he is
indebted for the reputation he deservedly enjoys, as the most agreeable
and successful lecturer in England.

Other causes than the misconception of a Brunel and a Faraday operated
to retard the practical success of this beautiful invention. The high
temperature which it was necessary to keep up in the circulating medium
of the engine, and the consequent oxidation, soon destroyed the
pistons, valves, and other working parts. These difficulties the
inventor endeavored to remedy, in an engine, which he subsequently
constructed, of much larger powers, but without success. His failure in
this respect, however, did not deter him from prosecuting his
invention. He continued his experiments from time to time, as
opportunity permitted, confident that he was gradually, but surely,
approaching the realization of his great scheme.