The idea of a machine to go by perpetual motion is perpetual
nonsense. Multitudes of boys and men have wasted much valuable time
in trying to find it, but they never can, as it is contrary to
natural laws, and therefore impossible; but one certainty of the
future is, that a million useful flying machines will flit hither and
thither; and one certainty of the present is, that while Cole's Book
Arcade contains 80,000 sorts of books, not a single person has yet
been able to come to it for a supply in a flying machine.--Laggard
inventors, think of this!
N.B.--Cole once invented a flying machine, but it wouldn't work!
[Page 127--Riddles And Catches]