Cornwall Iron
Furnace was one of many ironworks constructed in Pennsylvania
during a sixty-year period, form 1716-1776. At least twenty-one
blast furnaces, forty-five forges, four bloomeries, six steel
furnaces, three slitting mills, two plate mills, and one wire
mill operated in the colony. The production of these mills and
steel furnaces, irked English iron- and steelmakers because the
colonial American iron industry accounted for about one-seventh
of the world's output of pig iron, wrought iron, and castings.
By the early eighteenth century, England's metal industry
depended largely on bar and pig iron from Sweden, mostly because
English forests had been depleted by decades of charcoal
production. When dependence of the Swedish became burdensome,
Parliament passed the Iron Act of 1750 to encourage importation
into England of colonial pig iron and unfinished bar iron. The
act also forbade the establishment any new colonial sitting
mills, plate mills, or steel producing furnaces. Shipment of pig
and bar iron across the Atlantic increased and, in fact,
restrictions on the advanced iron products made in America were
largely ignored, so that the Iron Act was only a minor factor
among discontented colonists by the time of the American
Revolution.
A sizeable labor force was required to keep the iron plantation
running smoothly. Thirty to sixty people worked twelve-hour
shifts at the furnace. In addition, the iron works employed a
company clerk, teamsters, woodcutters, colliers
(charcoal-makers), farmers, and household servants. "From most
account, the workers were well-treated," says Strattan.
"However, there was a huge gap between the workers and the
owners." At the opposite end of the social and economic spectrum
from the laborers was the owner, or ironmaster, ruler of a
self-contained head of a community not unlike an Old World
feudal barony. He and his family inhabited a mansion of vast
acreage, and styled their way of life much like that of English
gentry.
Because this first stage of iron-both pig and cast-is
brittle, it was best suited for products that would not be
subject to continuous stress or repeated impact. Carbon-rich
cast iron was, however, suitable for heavy containers and
objects made to withstand fire. Reliable cannon barrels were
also made of cast iron. For items that required tougher iron,
bars of pig iron were transported to a forge where they were
further refined by heating and pounding. This stronger iron,
known as "wrought iron," could be forged into shapes, such as
horseshoes, or sent through a rolling or slitting mill to make
plates, bars, or nail rods.
What an impressive-though not necessarily pretty-sight the
furnace was when "in blast," which was twenty-four hours a day,
seven days a week, unless repairs were needed. From the huge
barn, buggies full of charcoal rumbled beneath the protective
roof of the connecting shed to the furnace building, then back
for another load. At the same time, creaking ore wagons drawn by
teams of horses or mules lugged iron ore up the road ascending
to the furnace. Loads of the components were carried across a
horizontal walkway to the open top of the towering furnace
stack, where they were dumped.
A large wooden waterwheel drove a twenty-foot-long bellows,
furnishing the air blast necessary to intensify the heat to
smelting temperatures. Eighteenth-century furnaces came to be
termed cold-blast to distinguish them from a nineteenth-century
improvement in which escaping inflammable gases were turned
around to pre-heat the air blast before it passed through the
tuyeres. During the nineteenth-century, some furnaces were
hot-blast while some were the older cold-blast type.
Eighteen to twenty charges a day resulted in output of
twenty-four tons of iron each week. At the base of the furnace,
guttermen raked the sand and dug channels for the molten pig
iron, then stacked the bars outside. Working conditions were
brutal; temperatures inside the casting house could reach as
high as 160 degrees Fahrenheit.
Three classifications of workers were employed at the
Cornwall Iron Furnace: free labor, indentured servants, and
slaves. While slaves were employed, there was opposition to
their importation. Throughout the eighteenth century acts were
passed restricting slave traffic, culminating in the 1780 act
for the gradual abolition of slavery, in which Pennsylvania
prohibited the importation of slaves. The hiring of indentured
servants proved problematic. Most of the redemptioners were
unskilled workers from Germany, England, and Ireland. Despite
their indenture, these servants ran away with alarming
frequency; perhaps for that reason they were hired in small
numbers.
Curttis and Peter Grubb, who had inherited Cornwall Iron
Furnace from their father, Peter Grubb Sr., upon his death in
1754, supported the American Revolution. Their furnace cast
cannon, shot, and ironware for the Continental cause. Labor was
in such short supply that the Grubbs and other ironmasters
received permission to use Hessian prisoners of war as workers.
Robert Coleman, who rose from the ranks and took over
Cornwall Iron Furnace and much of the mine from the Grubbs by
1798, was the first of four generations of Colemans who would
dominate Pennsylvania's ironmaking industry. Coleman arrived in
Philadelphia from Ireland in 1764. In two years he rose from a
clerkship in a prothonotary's office to a position as bookkeeper
for Curttis and Peter Grubb, during which he leaned about the
business and technology of ironmaking. He next served as a clerk
for ironmaster James Old at Quittapahilla Forge in Lebanon
County. He married Old's daughter Ann in 1773, the same year he
leased Salford Forge near Norristown, Montgomery County. |
