industrial biography-第71节
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occasion; where the forging required the most powerful blow; it
received next to no blow at all;the clear space for fall being
almost entirely occupied by the work on the anvil。
The obvious remedy was to invent some method; by which a block of
iron should be lifted to a sufficient height above the object on
which it was desired to strike a blow; and let the block fall down
upon the work;guiding it in its descent by such simple means as
should give the required precision in the percussive action of the
falling mass。 Following out this idea; Mr。 Nasmyth at once sketched
on paper his steam…hammer; having it clearly before him in his mind's
eye a few minutes after receiving Mr。 Humphries' letter narrating his
unlooked…for difficulty。 The hammer; as thus sketched; consisted of;
first an anvil on which to rest the work; second; a block of iron
constituting the hammer or blow…giving part; third; an inverted
steam…cylinder to whose piston…rod the block was attached。 All that
was then required to produce by such means a most effective hammer;
was simply to admit steam in the cylinder so as to act on the under
side of the piston; and so raise the block attached to the
piston…rod; and by a simple contrivance to let the steam escape and
so permit the block rapidly to descend by its own gravity upon the
work then on the anvil。 Such; in a few words; is the rationale of the
steam…hammer。
By the same day's post; Mr。 Nasmyth wrote to Mr。 Humphries; inclosing
a sketch of the invention by which he proposed to forge the 〃Great
Britain〃 paddle…shaft。 Mr。 Humphries showed it to Mr。 Brunel; the
engineer…inchief of the company; to Mr。 Guppy; the managing director;
and to others interested in the undertaking; by all of whom it was
heartily approved。 Mr。 Nasmyth gave permission to communicate his
plans to such forge proprietors as might feel disposed to erect such
a hammer to execute the proposed work;the only condition which he
made being; that in the event of his hammer being adopted; he was to
be allowed to supply it according to his own design。
The paddle…shaft of the 〃Great Britain〃 was; however; never forged。
About that time; the substitution of the Screw for the Paddle…wheel
as a means of propulsion of steam…vessels was attracting much
attention; and the performances of the 〃Archimedes〃 were so
successful as to induce Mr。 Brunel to recommend his Directors to
adopt the new power。 They yielded to his entreaty。 The great engines
which Mr。 Humphries had designed were accordingly set aside; and he
was required to produce fresh designs of engines suited for screw
propulsion。 The result was fatal to Mr。 Humphries。 The labour; the
anxiety; and perhaps the disappointment; proved too much for him; and
a brain…fever carried him off; so that neither his great paddle…shaft
nor Mr。 Nasmyth's steam…hammer to forge it was any longer needed。
The hammer was left to bide its time。 No forge…master would take it
up。 The inventor wrote to all the great firms; urging its superiority
to every other tool for working malleable iron into all kinds of
forge work。 Thus he wrote and sent illustrative sketches of his
hammer to Accramans and Morgan of Bristol; to the late Benjamin Hick
and Rushton and Eckersley of Bolton; to Howard and Ravenhill of
Rotherhithe; and other firms; but unhappily bad times for the iron
trade had set in; and although all to whom he communicated his design
were much struck with its simplicity and obvious advantages; the
answer usually given was〃We have not orders enough to keep in
work the forge…hammers we already have; and we do not desire at
present to add any new ones; however improved。〃 At that time no
patent had been taken out for the invention。 Mr。 Nasmyth had not yet
saved money enough to enable him to do so on his own account; and his
partner declined to spend money upon a tool that no engineer would
give the firm an order for。 No secret was made of the invention; and;
excepting to its owner; it did not seem to be worth one farthing。
Such was the unpromising state of affairs; when M。 Schneider; of the
Creusot Iron Works in France; called at the Patricroft works together
with his practical mechanic M。 Bourdon; for the purpose of ordering
some tools of the firm。 Mr。 Nasmyth was absent on a journey at the
time; but his partner; Mr。 Gaskell; as an act of courtesy to the
strangers; took the opportunity of showing them all that was new and
interesting in regard to mechanism about the works。 And among other
things; Mr。 Gaskell brought out his partner's sketch or 〃Scheme
book;〃 which lay in a drawer in the office; and showed them the
design of the Steam Hammer; which no English firm would adopt。 They
were much struck with its simplicity and practical utility; and M。
Bourdon took careful note of its arrangements。 Mr。 Nasmyth on his
return was informed of the visit of MM。 Schneider and Bourdon; but
the circumstance of their having inspected the design of his
steam…hammer seems to have been regarded by his partner as too
trivial a matter to be repeated to him; and he knew nothing of the
circumstance until his visit to France in April; 1840。 When passing
through the works at Creusot with M。 Bourdon; Mr。 Nasmyth saw a crank
shaft of unusual size; not only forged in the piece; but punched。 He
immediately asked; 〃How did you forge that shaft?〃 M。 Bourdon's
answer was; 〃Why; with your hammer; to be sure!〃 Great indeed was
Nasmyth's surprise; for he had never yet seen the hammer; except in
his own drawing! A little explanation soon cleared all up。 M。 Bourdon
said he had been so much struck with the ingenuity and simplicity of
the arrangement; that he had no sooner returned than he set to work;
and had a hammer made in general accordance with the design Mr。
Gaskell had shown him; and that its performances had answered his
every expectation。 He then took Mr。 Nasmyth to see the steam…hammer;
and great was his delight at seeing the child of his brain in full
and active work。 It was not; according to Mr。 Nasmyth's ideas; quite
perfect; and he readily suggested several improvements; conformable
with the original design; which M。 Bourdon forthwith adopted。
On reaching England; Mr。 Nasmyth at once wrote to his partner telling
him what he had seen; and urging that the taking out of a patent for
the protection of the invention ought no longer to be deferred。 But
trade was still very much depressed; and as the Patricroft firm
needed all their capital to carry on their business; Mr。 Gaskell
objected to lock any of it up in engineering novelties。 Seeing
himself on the brink of losing his property in the invention; Mr。
Nasmyth applied to his brother…in…law; William Bennett; Esq。; who
advanced him the requisite money for the purposeabout 280L。;
and the patent was secured in June 1840。 The first hammer; of 30
cwt。; was made for the Patricroft works; with the consent of the
partners; and in the course of a few weeks it was in full work。 The
precision and beauty of its actionthe perfect ease with which it
was managed; and the untiring force of its percussive blowswere
the admiration of all who saw it; and from that moment the
steam…hammer became a recognised power in modern mechanics。 The
variety or gradation of its blows was such; that it was found
practicable to manipulate a hammer of ten tons as easily as if it had
only been of ten ounces weight。 It was under such complete control
that while descending with its greatest momentum; it could be
arrested at any point with even greater ease than any instrument used
by hand。 While capable of forging an Armstrong hundred…pounder; or
the sheet…anchor for a ship of the line; it could hammer a nail; or
crack a nut without bruising the kernel。 When it came into general
use; the facilities which it afforded for executing all kinds of
forging had the effect of greatly increasing the quantity of work
done; at the same time that expense was saved。 The cost of making
anchors was reduced by at least 50 per cent。; while the quality of
the forging was improved。 Before its invention the manufacture of a
shaft of l5 or 20cwt。 required the concentrated exertions of a large
establishment; and its successful execution was regarded as a great
triumph of skill。; whereas forgings of 20 and 30 tons weight are now
things of almost every…day occurrence。 Its advantages were so
obvious; that its adoption soon became general; and in the course of
a few years Nasmyth steam…hammers were to be found in every
well…appointed workshop both at home and abroad。 Many modifications
have been made in the tool; by Condie; Morrison; Naylor; Rigby; and
others; but Nasmyth's was the father of them all; and still holds its
ground。*
'footnote。。。
Mr。 Nasmyth has lately introduced; with the assistance of Mr。 Wilson
of the Low Moor Iron Works; a new; exceedingly ingenious; and very
simple contrivance for working the hammer。