James Watt (1736-1819)

2

          Mr Watt on the Origin of his Improvements

prised of his design, I might at least have prevented the errors
respecting the facts in which I was concerned; but, upon the
whole, it is more surprising to me that his recollection should
have served him so well in narrating transactions of thirty years
standing, than that it should sometimes have led him astray. If
I had not retained some memorandums made at the time of, or
soon after, their occurrence, I should myself have felt great dif-
ficulty in recalling to mind the particulars at the period when I
first perused those articles, which was some time after their pub-
lication. I had about that period an opportunity of personally
stating to Dr Robison some remarks upon them, of which he
availed himself to a small extent in the Supplement to the En-
cyclopædia. Britannica, and probably would have done so still
more, had he been called upon to remould these articles.

I have endeavoured to throw most of my corrections into the
form of notes; but in some places I judged it necessary to alter
the text; which alterations I have marked to be printed in Ita-
lics, that they may be readily distinguished from the original.
In a few places I have cancelled part of the text without any
substitution, none appearing to me to be required. In others I
have left part of the reasoning unaltered which I did not concur
in; as in mere matters of opinion, where no manifest error was
involved, I did not conceive it proper to introduce my own spe-
culations.

As the subjects of Steam, and Steam-Engines, had been al-
most dismissed from my mind for many years previous to my
undertaking this revision, I have called in the aid of my friend
Mr John Southern, and of my son, whose daily avocations in
the manufacture of steam-engines, render them more conversant
with some points, to direct my attention to them; and of the
former, to examine such of the algebraic formulæ as appeared
essential, an office for which he is much better qualified than
myself; and he has accordingly marked those formulæ with his
initials.

I have not attempted to render Dr Robison’s memoir a com-
plete history of the Steam-Engine; nor have I even given a de-
tailed account of my own improvements upon it. The former
would have been an undertaking beyond my present powers,
and the latter must much have exceeded the limits of a com-
mentary upon my friend’s work. I have therefore confined my-