industrial biography-第22部分
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Mr。 Reynolds's advice was implicitly followed。 A patent was secured
in the name of the brothers Cranege; dated the 17th June; 1766; and
the identical words in the above letter were adopted in the
specification as descriptive of the process。 By this method of
puddling; as it is termed; the manufacturer was thenceforward enabled
to produce iron in increased quantity at a large reduction in price;
and though the invention of the Craneges was greatly improved upon by
Onions; and subsequently by Cort; there can be no doubt as to the
originality and the importance of their invention。 Mr。 Tylor states
that he was informed by the son of Richard Reynolds that the wrought
iron made at Coalbrookdale by the Cranege process 〃was very good;
quite tough; and broke with a long; bright; fibrous fracture: that
made by Cort afterwards was quite different。〃*
'footnote。。。
Mr。 TYLOR on Metal WorkReports on the Paris Exhibition of 1855。
Part II。 182。 We are informed by Mr。 Reynolds of Coed…du; a grandson
of Richard Reynolds; that 〃on further trials many difficulties arose。
The bottoms of the furnaces were destroyed by the heat; and the
quality of the iron varied。 Still; by a letter dated May; 1767; it
appears there had been sold of iron made in the new way to the value
of 247L。 14s。 6d。〃
。。。'
Though Mr。 Reynolds's generosity to the Craneges is apparent; in the
course which he adopted in securing for them a patent for the
invention in their own names; it does not appear to have proved of
much advantage to them; and they failed to rise above the rank which
they occupied when their valuable discovery was patented。 This;
however; was no fault of Richard Reynolds; but was mainly
attributable to the circumstance of other inventions in a great
measure superseding their process; and depriving them of the benefits
of their ingenuity。
Among the important improvements introduced by Mr。 Reynolds while
managing the Coalbrookdale Works; was the adoption by him for the
first time of iron instead of wooden rails in the tram…roads along
which coal and iron were conveyed from one part of the works to
another; as well as to the loading…places along the river Severn。 He
observed that the wooden rails soon became decayed; besides being
liable to be broken by the heavy loads passing over them; occasioning
much loss of time; interruption to business; and heavy expenses in
repairs。 It occurred to him that these inconveniences would be
obviated by the use of rails of cast…iron; and; having tried an
experiment with them; it answered so well; that in 1767 the whole of
the wooden rails were taken up and replaced by rails of iron。 Thus
was the era of iron railroads fairly initiated at Coalbrookdale; and
the example of Mr。 Reynolds was shortly after followed on all the
tramroads throughout the Country。
It is also worthy of note that the first iron bridge ever erected was
cast and made at the Coalbrookdale Worksits projection as well as
its erection being mainly due to the skill and enterprise of Abraham
Darby the third。 When but a young man; he showed indications of that
sagacity and energy in business which seemed to be hereditary in his
family。 One of the first things he did on arriving at man's estate
was to set on foot a scheme for throwing a bridge across the Severn
at Coalbrookdale; at a point where the banks were steep and slippery;
to accommodate the large population which had sprung up along both
banks of the river。 There were now thriving iron; brick; and pottery
works established in the parishes of Madeley and Broseley; and the
old ferry on the Severn was found altogether inadequate for ready
communication between one bank and the other。 The want of a bridge
had long been felt; and a plan of one had been prepared during the
life time of Abraham Darby the second; but the project was suspended
at his death。 When his son came of age; he resolved to take up his
father's dropped scheme; and prosecute it to completion; which he
did。 Young Mr。 Darby became lord of the manor of Madeley in 1776; and
was the owner of one…half of the ferry in right of his lordship。 He
was so fortunate as to find the owner of the other or Broseley half
of the ferry equally anxious with himself to connect the two banks of
the river by means of a bridge。 The necessary powers were accordingly
obtained from Parliament; and a bridge was authorized to be built 〃of
cast…iron; stone; brick; or timber。〃 A company was formed for the
purpose of carrying out the project; and the shares were taken by the
adjoining owners; Abraham Darby being the principal subscriber。*
'footnote。。。
Among the other subscribers were the Rev。 Mr。 Harris; Mr。 Jennings;
and Mr。 John Wilkinson; an active promoter of the scheme; who gave
the company the benefit of his skill and experience when it was
determined to construct the bridge of iron。 For an account of John
Wilkinson see Lives of the Engineers; vol。 ii。 337; 356。 In the
description of the first iron bridge given in that work we have; it
appears; attributed rather more credit to Mr。 Wilkinson than he is
entitled to。 Mr。 Darby was the most active promoter of the scheme;
and had the principal share in the design。 Wilkinson nevertheless was
a man of great energy and originality。 Besides being the builder of
the first iron ship; he was the first to invent; for James Watt; a
machine that would bore a tolerably true cylinder。 He afterwards
established iron works in France; and Arthur Young says; that 〃until
that well…known English manufacturer arrived; the French knew nothing
of the art of casting cannon solid and then boring them〃 (Travels in
France; 4to。 ed。 London; 1792; p。90)。 Yet England had borrowed her
first cannon…maker from France in the person of Peter Baude; as
described in chap。 iii。 Wilkinson is also said to have invented a
kind of hot…blast; in respect of which various witnesses gave
evidence on the trial of Neilson's patent in 1839; but the invention
does not appear to have been perfected by him。
。。。'
The construction of a bridge of iron was an entirely new idea。 An
attempt had indeed been made at Lyons; in France; to construct such a
bridge more than twenty years before; but it had entirely failed; and
a bridge of timber was erected instead。 It is not known whether the
Coalbrookdale masters had heard of that attempt; but; even if they
had; it could have been of no practical use to them。
Mr。 Pritchard; an architect of Shrewsbury; was first employed to
prepare a design of the intended structure; which is still preserved。
Although Mr。 Pritchard proposed to introduce cast…iron in the arch of
the bridge; which was to be of 120 feet span; it was only as a sort
of key; occupying but a few feet at the crown of the arch。 This
sparing use of cast iron indicates the timidity of the architect in
dealing with the new materialhis plan exhibiting a desire to effect
a compromise between the tried and the untried in
bridge…construction。 But the use of iron to so limited an extent; and
in such a part of the structure; was of more than questionable
utility; and if Mr。 Pritchard's plan had been adopted; the problem of
the iron bridge would still have remained unsolved。
The plan; however; after having been duly considered; was eventually
set aside; and another; with the entire arch of cast…iron; was
prepared under the superintendence of Abraham Darby; by Mr。 Thomas
Gregory; his foreman of pattem…makers。 This plan was adopted; and
arrangements were forthwith made for carrying it into effect。 The
abutments of the bridge were built in 1777…8; during which the
castings were made at the foundry; and the ironwork was successfully
erected in the course of three months。 The bridge was opened for
traffic in 1779; and proved a most serviceable structure。 In 1788 the
Society of Arts recognised Mr。 Darby's merit as its designer and
erector by presenting him with their gold medal; and the model of the
bridge is still to be seen in the collection of the Society。 Mr。
Robert Stephenson has said of the structure: 〃 If we consider that
the manipulation of cast…iron was then completely in its infancy; a
bridge of such dimensions was doubtless a bold as well as an original
undertaking; and the efficiency of the details is worthy of the
boldness of the conception。〃*
'footnote。。。
Encyclopaedia Britannica; 8th ed。 Art。 〃Iron Bridges。〃
。。。'
Mr。 Stephenson adds that from a defect in the construction the
abutments were thrust inwards at the approaches and the ribs
partially fractured。 We are; however; informed that this is a
mistake; though it does appear that the apprehension at one time
existed that such an accident might possibly occur。
To remedy the supposed defect; two small land arches were; in the
year 1800; substituted for the stone approach on the Broseley side of
the bridge。 While the work was in progress; Mr。 Telford; the
well…known engineer; carefully examined the bridge; and thus spoke of
its condition at the time: 〃The great improvement of erecting upon
a navigable river a bridge of cast…iron of one arch only was first
put in practice near Coalbrookdale。 The bridge was executed in 1777
by Mr。 Abraham Darby; and the ironwork is now quite as perfect as
when it was first put up。 Drawings of this bridge have long been
before the public; and have been much and justly admired。〃*
'footnote。。。
PLYMLEY; General View of the Agriculture of Shropshire。
。。。'
A Coalbrookdale correspondent; writing in May; 1862; informs us that
〃at the present time the bridge is undergoing repair; and; special
examination having been made; there is no appearance either that the
abutments have moved; or that the ribs have been broken in the centre
or are out of their proper right line。 There has; it is true; been a
strain on the land arches; and on the roadway plates; which; however;
the main arch has b