Environment, Technology, and Community in Salisbury
Salisbury’s particular combination of natural resources allowed iron- making to continue for nearly 200 years from its 1736 start. In the first hundred years of mining and smelting, the district’s entrepreneurs had established a place for themselves in the national market for high-quality iron products while they managed their mineral, waterpower, and forest resources to meet the demands of expanded production. Each resource offered different challenges. An ironmaker could cut wood without thought of replacement or could manage woodland for sustained yield. As miners dug deeper for ore, they had more spoil to dispose of. They also had to devise drainage systems for their pits. Waterpower systems needed maintenance, repairs after freshets, control of their watersheds if siltation of the power ponds was to be avoided, and cooperative agreements among users. To meet the demands of expanding business, a forge owner might have to develop a new power site, as Forbes & Adam did when they put their second rolling mill in Woodville instead of Canaan. Fuel supply eventually proved the most critical natural resource problem for the ironmakers. Woodland previously burned by Indians made a good initial source of ironworks fuel, since wood from small trees coaled easily. The Lakeville blast furnace had a capacity of 2.5 tons of iron per day and fuel consumption of 250 bushels of charcoal per ton of iron made. In 1776 the furnace operated seven months, the length of a typical blast, and so would have made about 525 tons of iron while consuming fuel from about 200 acres (0.3 square miles) of woodland. At this rate of production, the furnace would have consumed at most 5.4 square miles of forest, 9 percent of the area of the town of Salisbury, between its start-up date (1762) and 1780. An eighteenth-century bloomery typically made about 250 pounds of iron per day with a fuel rate of about six. If it worked 300 days per year (a high estimate), it would have used wood at the rate of 42 acres per year. From 1736 to 1780, one bloomery would have consumed the wood from 2.9 square miles of forest.