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.