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 children were born out of wedlock, held a good position in their neighbourhood, and were regarded with respect. Lord Dudley, though married and having legitimate heirs at the time, seems to have attended to the up-bringing of his natural children; educating them carefully, and afterwards employing them in confidential offices connected with the management of his extensive property. Dud describes himself as taking great delight, when a youth, in his father's iron-works near Dudley, where he obtained considerable knowledge of the various processes of the manufacture.