view of Watt's work. Farey as a young man
had several times talked with the aging Watt, and he had reflected upon
the nature of the intellect that had caused Watt to be recognized as a
genius, even within his own lifetime. In attempting to explain Watt's
genius, Farey set down some observations that are pertinent not only to
kinematic synthesis but to the currently fashionable term "creativity."

In Farey's opinion Watt's inventive faculty was far superior to that of
any of his contemporaries; but his many and various ideas would have
been of little use if he had not possessed a very high order of
judgment, that "faculty of distinguishing between ideas; decomposing
compound ideas into more simple elements; arranging them into classes,
and comparing them together...."

Farey was of the opinion that while a mind like Watt's could produce
brilliant new ideas, still the "common stock of ideas which are current
amongst communities and professions, will generally prove to be of a
better quality than the average of those new ideas, which can be
produced by any individual from the operation of his own mind, without
assistance from others." Farey concluded with the observation that "the
most useful additions to that common stock, usually proceed from the
individuals who are well acquainted with the whole series."[25]

[Footnote 25: Farey, _op. cit._ (footnote 6), pp. 651, 652.]

To Draw a Straight Line

During most of the century after James Watt had produced his parallel
motion, the problem of devising a linkage, one point of which would
describe a straight line, was one that tickled the fancies of
mathematicians, of ingenious mechanics, and of gentlemanly dabblers in
ideas. The quest for a straight-line mechanism more accurate than that
of Watt far outlasted the pressing practical need for such a device.
Large metal planing machines were well known by 1830, and by midcentury
crossheads and crosshead guides were used on both sides of the Atlantic
in engines with and without working beams.

By 1819 John Farey had observed quite accurately that, in England at
least, many other schemes had been tried and found wanting and that "no
methods have been found so good as the original engine; and we
accordingly find, that all the most established and experienced
manufacturers make engines which are not altered in any great feature
from Mr. Watt's original engine...."[26]

[Footnote 26: In Rees, _op. cit._ (footnote 21), vol. 34