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 hea