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Mushet And Bessemer
That Mushet was "used" by Ebbw Vale against Bessemer is, perh...

Annealing
ANNEALING can be done by heating to temperatures ranging from...

Air-hardening Steels
These steels are recommended for boring, turning and planing...

Tempering Colors On Carbon Steels
Opinions differ as to the temperature which is indicated by t...

Carbon Tool Steel
Heat to a bright red, about 1,500 to 1,550 deg.F. Do not ham...

Leeds And Northrup Optical Pyrometer
The principles of this very popular method of measuring tempe...

Heavy Forging Practice
In heavy forging practice where the metal is being worked at...

Judging The Heat Of Steel
While the use of a pyrometer is of course the only way to hav...

Optical System And Electrical Circuit Of The Leeds & Northrup Optical Pyrometer
For extremely high temperature, the optical pyrometer is lar...

The Theory Of Tempering
Steel that has been hardened is generally harder and more br...

Hardening High-speed Steel
In forging use coke for fuel in the forge. Heat steel slowly ...

Hardening
The forgings can be hardened by cooling in still air or quen...

Affinity Of Nickel Steel For Carbon
The carbon- and nickel-steel gears are carburized separately...

Cyanide Bath For Tool Steels
All high-carbon tool steels are heated in a cyanide bath. Wi...

Steel Before The 1850's
In spite of a rapid increase in the use of machines and the ...

Preventing Decarbonization Of Tool Steel
It is especially important to prevent decarbonization in such...

Heat-treating Equipment And Methods For Mass Production
The heat-treating department of the Brown-Lipe-Chapin Company...

An Automatic Temperature Control Pyrometer
Automatic temperature control instruments are similar to the ...

High-carbon Machinery Steel
The carbon content of this steel is above 30 points and is ha...

Correction For Cold-junction Errors
The voltage generated by a thermo-couple of an electric pyrom...



Robert Mushet








Robert (Forester) Mushet (1811-1891), born in the Forest of Dean,
Gloucestershire, of a Scots father (David, 1772-1847) himself a noted
contributor to the metallurgy of iron and steel, is, like the American
William Kelly, considered by many to have been a victim of Bessemer's
astuteness--or villainy. Because of Robert Mushet's preference for the
quiet of Coleford, many important facts about his career are lacking;
but even if his physical life was that of a recluse, his frequent and
verbose contributions to the correspondence columns of the technical
press made him well-known to the iron trade. It is from these letters
that he must be judged.

In view of his propensity to intervene pontifically in every discussion
concerning the manufacture of iron and steel, it is somewhat surprising
that he refrained from comment on Bessemer's British Association
address of August 1856 for more than fourteen months. The debate was
opened over the signature of his brother David who shared the family
facility with the pen.[22] Recognizing Bessemer's invention as a
"congruous appendage to [the] now highly developed powers of the blast
furnace" which he describes as "too convenient, too powerful and too
capable of further development to be superseded by any retrograde
process," David Mushet greeted Bessemer's discovery as "one of the
greatest operations ever devised in metallurgy."[23] A month later,
however, David Mushet had so modified his opinion of Bessemer as to
come to the conclusion that the latter "must indeed be classed with the
most unfortunate inventors." He gave as his reason for this turnabout
his discovery that Joseph Martien had demonstrated his process of
"purifying" metal successfully and had indeed been granted a
provisional patent a month before Bessemer. The sharp practice of
Martien's patent lawyer, Mushet claimed, had deprived him of an
opportunity of proving priority of invention against Bessemer. Mushet
was convinced that Martien's was the first in the field.[24]

[22] See Mining Journal, 1857, vol. 27, pp. 839 and 855. David
Mushet withdrew from the discussion after 1858 and his relapse
into obscurity is only broken by an appeal for funds for the
family of Henry Cort. A biographer of the Mushets is of the
opinion that Robert Mushet wrote these letters and obtained
David's signature to them (Fred M. Osborn, The story of the
Mushets, London, 1952, p. 44, footnote). The similarity in the
style of the two brothers is extraordinary enough to support this
idea. If this is so, Robert Mushet who disagreed with himself as
"Sideros" was also in controversy with himself writing as
"David."

[23] Mining Journal, 1856, vol. 26, p. 567.

[24] Ibid., pp. 631 and 647. The case of Martien will be
discussed below (p. 36). David Mushet had overlooked Bessemer's
patent of January 10, 1855.

Robert Mushet's campaign on behalf of his own claims to have made the
Bessemer process effective was introduced in October 1857, two years
after the beginning of Bessemer's experiment and after one year of
silence on Bessemer's part. Writing as "Sideros"[25] he gave credit to
Martien for "the great discovery that pig-iron can, whilst in the fluid
state, be purified ... by forcing currents of air under it ...," though
Martien had failed to observe the use of temperature by the "deflation
of the iron itself"; and for discovering that--

when the carbon has been all, or nearly all, dissipated, the
temperature increases to an almost inconceivable extent, so that
the mass, when containing only as much carbon as is requisite to
constitute with it cast steel ... still retains a perfect degree of
fluidity.

[25] Mining Journal, 1857, vol. 27, p. 723. Robert Mushet was a
constant correspondent of the Mining Journal from 1848. The
adoption of a pseudonym, peculiar apparently to 1857-1858 (see
Dictionary of national biography, vol. 39, p. 429), enabled him
to carry on two debates at a time and also to sing his own
praises.

This, says "Sideros," was no new observation; "it had been before the
metallurgical world, both practical and scientific, for centuries," but
Bessemer was the first to show that this generation of heat could be
attained by blowing cold air through the melted iron. Mushet goes on to
show, however, that the steel thus produced by Bessemer was not
commercially valuable because the sulphur and phosphorous remained, and
the dispersion of oxide of iron through the mass "imported to it the
inveterate hot-short quality which no subsequent operation could
expel." "Sideros" concludes that Bessemer's discovery was "at least for
a time" now shelved and arrested in its progress; and it had been left
"to an individual of the name of Mushet" to show that if "fluid
metallic manganese" were combined with the fluid Bessemer iron, the
portion of manganese thus alloyed would unite with the oxygen of the
oxide and pass off as slag, removing the hot-short quality of the iron.
Robert Mushet had demonstrated his product to "Sideros" and had
patented his discovery, though "not one print, literary or scientific,
had condescended to notice it."

"Sideros" viewed Mushet's discovery as a "spark amongst dry faggots
that will one day light up a blaze which will astonish the world when
the unfortunate inventor can no longer reap the fruits of his life-long
toil and unflinching perseverance." In an ensuing letter he[26] summed
up the situation as he saw it:

Nothing that Mr. Mushet can hereafter invent can entitle him to the
merit of Mr. Bessemer's great discovery ... and ... nothing that Mr.
Bessemer may hereafter patent can deprive Mr. Robert Mushet of having
been the first to remove the obstacles to the success of Mr. Bessemer's
process.

[26] Ibid., p. 823. Mushet's distinction between an inventor
and a patentee is indicative of the disdain of a son of David
Mushet for an amateur (see also p. 886).

Bessemer still did not intervene in the newspaper discussion; nor had
he had any serious supporters, at least in the early stage.[27]

[27] One William Green had commented extensively on David
Mushet's early praise of the Bessemer process and on his sudden
reversal in favor of Martien soon after Bessemer's British
Association address (Mechanics' Magazine, 1856, vol. 65, p. 373
ff.). Green wrote from Caledonian Road, and the proximity to
Baxter House, Bessemer's London headquarters, suggests the
possibility that Green was writing for Bessemer.

Publication in the Mining Journal of a list of Mushet's patents,[28]
evidently in response to Sideros' complaint, now presented Bessemer
with notice of Robert Mushet's activity, even if he had not already
observed his claims as they were presented to the Patent Office.
Mushet, said the Mining Journal--

appears to intend to carry on his researches from the point where
Mr. J. G. Martien left off and is proceeding on the Bessemer plan
of patenting each idea as it occurs to his imaginative brain. He
proposes to make both iron and steel but does not appear to have
quite decided as to the course of action ... to accomplish his
object, and therefore claims various processes, some of which are
never likely to realize the inventor's expectations, although
decidedly novel, whilst others are but slight modification of
inventions which have already been tried and failed.

[28] Mining Journal, 1857, vol. 27, p. 764.

The contemporary attitude is reflected in another comment by the
Mining Journal:[29]

Although the application of chemical knowledge to the manufacture
of malleable iron cannot fail to produce beneficial results, the
quality of the metal depends more upon the mechanical than the
chemical processes.... Without wishing in any way to discourage the
iron chemists, we have no hesitation in giving this as our opinion
which we shall maintain until the contrary be actually proved. With
regard to steel, there may be a large field for chemical research
... however, we believe that unless the iron be of a nature adapted
for the manufacture of steel by ordinary processes, the purely
chemical inventions will only give a metal of a very uniform
quality.

[29] Ibid., p. 764.

Another correspondent, William Green, was of the opinion that Mushet's
"new compounds and alloys," promised well as an auxiliary to the
Bessemer process but that "the evil which it was intended to remove was
more visionary than real." Bessemer's chief difficulty was the
phosphorus, not the oxide of iron "as Mr. Mushet assumes." This,
Bessemer no doubt would deal with in due course, but meanwhile he did
well "to concentrate his energies upon the steel operations," after
which he would have time to tackle "the difficulties which have so far
retarded the iron operations."[30]

[30] Ibid., p. 791.

Mushet[31] claims to have taken out his patent of September 22, 1856,
covering the famous "triple compound," after he--

had fully ascertained, upon the ordinary scale of manufacture that
air-purified cast-iron, when treated as set forth in my
specifications, would afford tough malleable iron ... I found,
however, that the remelting of the coke pig-iron, in contact with
coke fuel, hardened the iron too much, and it became evident that
an air-furnace was more proper for my purpose ... [the
difficulties] arose, not from any defect in my process, but were
owing to the small quantity of the metal operated upon and the
imperfect arrangement of the purifying vessel, which ought to be so
constituted that it may be turned upon an axis, the blast taken
off, the alloy added and the steel poured out through a spout ...
Such a purifying vessel Mr. Bessemer has delineated in one of his
patents.

[31] Ibid., p. 770 (italics supplied).

Mushet also claimed to have designed his own "purifying and mixing"
furnace, of 20-ton capacity, which he had submitted to the Ebbw Vale
Iron Works "many months ago," without comment from them. There is an
intriguing reference to the painful subject of two patents not
proceeded with, and not discussed "in the avaricious hope that the
parties connected with the patents will make me honorable amends ...
these patents were suppressed without my knowledge or consent." Lest
his qualifications should be questioned, Mushet concludes:

I do not profess to be an iron chemist, but I have undoubtedly made
more experiments upon the subject of iron and steel than any man
now living and I am thereby enabled to say that all I know is but
little in comparison with what has yet to be discovered.

So began Mushet's claim to have solved Bessemer's problem, a claim
which was to fill the correspondence columns of the engineering
journals for the next ten years. Interpretation of this correspondence
is made difficult by our ignorance of the facts concerning the control
of Mushet's patents. These have to be pieced together from his
scattered references to the subject.

His experiments were conducted, at least nearly up to the close of the
year 1856, with the cooperation of Thomas Brown of the Ebbw Vale Iron
Works.[32] The price of this assistance was apparently half interest in
Mushet's patents, though for reasons which Mushet does not explain the
deed prepared to effect the transfer was never executed.[33] Mushet
continued, however, to regard the patents as "wholly my own, though at
the same time, I am bound in honor to take no unfair advantage of the
non-execution of that deed." A possible explanation of this situation
may be found in Ebbw Vale's activities in connection with Martien and
Bessemer, as well as with an Austrian inventor, Uchatius.

[32] Ibid., p. 770.

[33] Ibid., p. 823.





Next: Ebbw Vale And The Bessemer Process

Previous: Steel Before The 1850's



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