Five furnaces were in operation at the Lehigh Crane Iron Company in 1854, together producing an average of 750 tons of pig iron a week. They were the first commercially and technically successful anthracite-fired iron furnaces in North America, and they spurred the rapid development of an iron industry using anthracite coal, first in the Lehigh Valley and then in Pennsylvania, New Jersey, New York, and Maryland. By 1873, 46 percent of all iron made in the United States came from anthracite furnaces, nearly three quarters of them in Pennsylvania, where half of all American iron was made. The success of Crane Iron and other Lehigh Valley iron companies fueled a major mining boom in Lehigh County, where 261 mines of varying size were opened, some by independent operators, some leased by iron companies, and some owned outright by the companies. In 1875, Crane Iron leased 11 limonite mines in Lehigh County, owned three outright, and one jointly. David Thomas, born and educated in Wales, entered the iron industry at age 17 and by 23 was superintendent of the Yniscedwyn Ironworks in southern Wales. After early failures using anthracite, Thomas and George Crane enlarged their furnace and applied hot blasts of air, raising furnace temperatures and sharply increasing iron production. In 1838, Erskine Hazard traveled to Wales and hired Thomas to come to Pennsylvania to use Lehigh Coal and Navigation Company anthracite in a new iron business along the Lehigh Navigation. In August 1839, Thomas began constructing his furnace beside Lock 36, where water diverted from the canal turned a waterwheel that powered the hot-blast machinery. The furnace was successfully blown in at 5 o'clock PM on July 3, 1840, and its first cast of about 4 tons of iron was made on July 4. In later years Thomas founded the Thomas Iron Works and the village of Hokendauqua, where its first furnaces were located, and he also founded the Union foundry and Catasauqua Manufacturing Company, the Lehigh Firebrick Works, and the National Bank of Catasauqua.