, Matthew
Boulton, they were placed at his disposal.

Watt's genius was nowhere more evident than in his synthesis of
linkages. An essential ingredient in the success of Watt's linkages,
however, was his partner's appreciation of the entirely new order of
refinement that they called for. Matthew Boulton, who had been a
successful manufacturer of buttons and metal novelties long before his
partnership with Watt was formed, had recognized at once the need for
care in the building of Watt's steam engine. On February 7, 1769, he had
written Watt:[2] "I presumed that your engine would require money,
very accurate workmanship and extensive correspondence to make it turn
out to the best advantage and that the best means of keeping up the
reputation and doing the invention justice would be to keep the
executive part of it out of the hands of the multitude of empirical
engineers, who from ignorance, want of experience and want of necessary
convenience, would be very liable to produce bad and inaccurate
workmanship; all of which deficiencies would affect the reputation of
the invention." Boulton expected to build the engines in his shop "with
as great a difference of accuracy as there is between the blacksmith and
the mathematical instrument maker." The Soho Works of Boulton and Watt,
in Birmingham, England, solved for Watt the problem of producing "in
great" (that is, in sizes large enough to be useful in steam engines)
the mechanisms that he devised.[3]

[Footnote 2: Henry W. Dickinson, _James Watt, Craftsman & Engineer_,
Cambridge, Cambridge University Press, 1936, pp. 52-53.]

[Footnote 3: James P. Muirhead, _The Origin and Progress of the
Mechanical Inventions of James Watt_, London, 1854, vol. 1, pp. 56, 64.
This work, in three volumes, contains letters, other documents, and
plates of patent specification drawings.]

The contributions of Boulton and Watt to practical mechanics "in great"
cannot be overestimated. There were in the 18th century instrument
makers and makers of timekeepers who had produced astonishingly
accurate work, but such work comprised relatively small items, all being
within the scope of a bench lathe, hand tools, and superb handwork. The
rapid advancement of machine tools, which greatly expanded the scope of
the machine-building art, began during the Boulton and Watt partnership
(1775-1800).

In April 1775 the skirmish at Concord between American colonists and
British redcoats marked the beginning