oir below
and the stem as tall as you please." He also made an instrument for
determining the specific gravity of liquids, and a year after this he
"found out a method of working tubes of the elastic resin without
dissolving it." The importance of such tubes for a thousand purposes in
the arts and sciences is now appreciated.

Watt gave much time to an arithmetical machine which he found
exceedingly simple to plan, but he adds, "I have learnt by experience
that in mechanics many things fall out between the cup and the mouth."
He describes what it is to accomplish, but it remained for Babbage at a
much later date to perfect the machine. A machine for copying sculpture
amused him for a time but it was never finished.

If any difficulty of a mechanical nature arose, people naturally turned
to Watt for a solution. Thus the Glasgow University failed to get pipes
for conveying water across the Clyde to stand, the channel of the river
being covered with mud and shifty sand, full of inequalities, and
subject to the pressure of a considerable body of water. Application was
at last made to the recognised genius. If he could not solve it, who
could? This was just one of the things that Watt liked to do. He
promptly devised an articulated suction pipe with parts formed on the
principle of a lobster's tail. This crustacean tube a thousand feet long
solved the matter. Watt stated that his services were induced solely by
a desire to be of use in procuring good water to the city of Glasgow,
and to promote the prosperity of a company which had risked so much for
the public good. These were handsomely acknowledged by the presentation
to him of a valuable piece of plate.

As another proof of Watt's habit of thinking of everything that could
possibly be improved, it may be news to many readers that the
consumption of the smoke from steam engines early attracted his
attention, and that he patented devices for this. These have been
substantially followed in the numerous attempts which have been made
from time to time to reduce the huge volumes of smoke that keep so many
cities under a cloud. He was successful and his son James writes to him
in 1790 from Manchester:

It is astonishing what an impression the smoke-consuming power
of the engine has made upon everybody hereabouts. They scarcely
trusted to the evidence of their senses. You would be diverted
to hear the strange hypotheses which have been stated to account