were mysteries, the communication of which to others was carefully
guarded by the regulations of the trades guilds. Although the early
patents are called specifications, they in reality specify nothing.
They are for the most part but a mere haze of words, from which very
little definite information can be gleaned as to the processes
patented. It may be that Sturtevant had not yet reduced his idea to
any practicable method, and therefore could not definitely explain it.
However that may be, it is certain that his process failed when tried
on a large scale, and Sturtevant's patent was accordingly cancelled at
the end of a year.

The idea, however, had been fairly born, and repeated patents were
taken out with the same object from time to time. Thus, immediately on
Sturtevant's failure becoming known, one John Rovenzon, who had been
mixed up with the other's adventure, applied for a patent for making
iron by the same process, which was granted him in 1613. His 'Treatise
of Metallica'[3] shows that Rovenzon had a true conception of the
method of manufacture. Nevertheless he, too, failed in carrying out
the invention in practice, and his patent was also cancelled. Though
these failures were very discouraging, like experiments continued to be
made and patents taken out,--principally by Dutchmen and
Germans,[4]--but no decided success seems to have attended their
efforts until the year 1620, when Lord Dudley took out his patent "for
melting iron ore, making bar-iron, &c., with coal, in furnaces, with
bellows." This patent was taken out at the instance of his son Dud
Dudley, whose story we gather partly from his treatise entitled
'Metallum Martis,' and partly from various petitions presented by him
to the king, which are preserved in the State Paper Office, and it runs
as follows:--

Dud Dudley was born in 1599, the natural son of Edward Lord Dudley of
Dudley Castle in the county of Worcester. He was the fourth of eleven
children by the same mother, who is described in the pedigree of the
family given in the Herald's visitation of the county of Stafford in
the year 1663, signed by Dud Dudley himself, as "Elizabeth, daughter of
William Tomlinson of Dudley, concubine of Edward Lord Dudley." Dud's
eldest brother is described in the same pedigree as Robert Dudley,
Squire, of Netherton Hall; and as his sisters mostly married well,
several of them county gentlemen, it is obvious that the family,
notwithstanding that the ch