rought together
in their relative positions in a mould, heated to a welding heat, and
then by a blow of the steam hammer, furnished with dies, are stamped
into a complete and all but finished wheel. It is evident that
wherever wrought-iron articles of a manageable size have to be produced
in considerable quantities, the same process may be adopted, and the
saving effected by the substitution of this for the ordinary forging
process will doubtless ere long prove incalculable. For this, as for
the many other advantageous uses of the steam-hammer, we are primarily
and mainly indebted to Mr. Nasmyth. It is but right, therefore, that
we should hold his name in honour. In fact, when we think of the
universal service which this machine is rendering us, we feel that some
special expression of our indebtedness to him would be a reasonable and
grateful service. The benefit which he has conferred upon us is so
great as to justly entitle him to stand side by side with the few men
who have gained name and fame as great inventive engineers, and to whom
we have testified our gratitude--usually, unhappily, when it was too
late for them to enjoy it."

Mr. Nasmyth subsequently applied the principle of the steam-hammer in
the pile driver, which he invented in 1845. Until its production, all
piles had been driven by means of a small mass of iron falling upon the
head of the pile with great velocity from a considerable height,--the
raising of the iron mass by means of the "monkey" being an operation
that occupied much time and labour, with which the results were very
incommensurate. Pile-driving was, in Mr. Nasmyth's words, conducted on
the artillery or cannon-ball principle; the action being excessive and
the mass deficient, and adapted rather for destructive than impulsive
action. In his new and beautiful machine, he applied the elastic force
of steam in raising the ram or driving block, on which, the block being
disengaged, its whole weight of three tons descended on the head of the
pile, and the process being repeated eighty times in the minute, the
pile was sent home with a rapidity that was quite marvellous compared
with the old-fashioned system. In forming coffer-dams for the piers
and abutments of bridges, quays, and harbours, and in piling the
foundations of all kinds of masonry, the steam pile driver was found of
invaluable use by the engineer. At the first experiment made with the
machine, Mr. Nasmyth drove a 14-inch pi