The most significant fact about the "poor potter" is the revelation that he made stoneware. Stoneware manufacture is a sophisticated art, requiring special clays, high-temperature firing, and the ability to use salt in glazing. When William Rogers acquired his first lots in Yorktown in 1711, no stoneware, so far as we know, was being made in North America. By 1725, when Rogers sold earthenware to John Mercer, the Duché family apparently had just succeeded in making stoneware in Philadelphia.[224] Since we have no documentary evidence of Rogers' first production of stoneware, we do not know whether his stoneware antedated that of the Duchés; we know only that after he died in 1739 numerous pieces of stoneware were listed in what were obviously the effects of his pottery shop. There is strong archeological evidence, however, that it was made about 1730 (see p. 110). Although Rogers may not have been the first to make stoneware in colonial North America, that he was at least one of the first must have elevated him to a position of prominence among colonial potters. Far from being a poor potter who conducted a business "with very little advantage to himself, and without any damage to Trade," he was supplying a colonial market that heretofore had been filled solely from England and Germany. There is a hint that he may have shipped his wares to North Carolina, because the _Virginia Gazette_ announced on September 21, 1739: "Cler'd out of York River ... September 11. Sloop Thomas and Tryal, of North Carolina, John Nelson, for North Carolina ... some Stone Ware."[225] Three years before, Rogers had sued in court to collect "a Bill Payable to him from one Richard Saunderson of North Carolina."[226] The possibility that the stoneware in the sloop _Thomas and Tryal_ had been made by Rogers is highly conjectural, since European imports often were redistributed and transshipped in American ports. But, since its cargo as a whole consisted of non-European materials, this still remains a possibility. The most notable inference that Rogers' stoneware may have infiltrated distant colonial markets is found in the Petition of Isaac Parker to the Massachusetts Court to establish a stoneware manufactory in Charlestown, Massachusetts, filed in September 1742: "... there are large quantities of said ware imported into this Province every year from New York, Philadelphia, & Virginia, for which ... returns are mostly made in Silver and Gold by the gentn who receive them here."[227]