ridge, has told me that
there will be used upwards of 2,000 more tons of material in the Forth
Bridge, to resist the wind pressure, than would have been needed if no
wind had to be taken into account, and if the question of the simple
weight to be carried had alone to be considered. With respect to the
foundation of bridges, that ingenious man, Lord Cochrane, patented a
mode of sinking foundations, even before the first meeting of the
British Association, viz., as far back, I believe, as 1825 or 1826;
and the improvements which he then invented are almost universally in
use in bridge construction at the present day. Cylinders sunk by the
aid of compressed air, airlocks to obtain access to the cylinder, and,
in fact, every means that I know of as having been used in the modern
sinking of cylinder foundations, were described by Lord Cochrane
(afterwards Earl of Dundonald) in that specification.

The next subject I propose to touch on is that of

MACHINE TOOLS.

In 1831, the mention of lathes, drilling machines, and screwing
machines brings me very nearly to the end of the list of the machine
tools used by turners and fitters, and at that time many lathes were
without slide rests. The boiler-maker had then his punching-press and
shearing machine; the smith, leaving on one side his forges and their
bellows, had nothing but hand tools, and the limit of these was a huge
hammer, with two handles, requiring two men to work it. In anchor
manufacture, it is true, a mechanical drop-hammer, known as a
Hercules, was employed, while in iron works, the Helve and the Tilt
hammer were in use. For ordinary smith's work, however, there were, as
has been said, practically no machine tools at all.

This paucity or absence in some trades, as we have seen, of machine
tools, involved the need of very considerable skill on the part of the
workman. It required the smith to be a man not only of great muscular
power, but to be possessed of an accurate eye and a correct judgment,
in order to produce the forgings which were demanded of him, and to
make the sound work that was needed, especially when that soundness
was required in shafts, and in other pieces which, in those days, were
looked upon as of magnitude; which, indeed, they were, relatively to
the tools which could be brought to operate upon them. The
boiler-maker in his work had to trust almost entirely to the eye for
correctness of form and for regularity of punching, while all parts