If you ever climbed Mount Marcy from Lake Colden, you probably drove up the narrow road from Newcomb to the Upper Works trailhead, past an odd but massive stone structure near the southern entrance to the High Peaks. You might have wondered about this relic from the American industrial revolution, how it worked, and when it was built.

In a few months, the Open Space Institute (OSI), which bought the site from NL Industries in 2003, will install illustrated interpretive panels explaining the fascinating history of this important Adirondack site. I’ve been working on the team preparing these panels, and I’ve learned far more about 19th-century iron smelting than I ever thought was possible.

Bob McNamara, an artist and interpretive designer from Cleveland, NY, of Art of Wilderness, is in charge of the project. Representatives from the Town of Newcomb, the Adirondack Museum, the DEC, the Adirondack Ecological Center, Adirondack Architectural Heritage, and the state office of Parks, Recreation & Historic Preservation are advising us.

The 2003 OSI purchase included about 10,000 acres, including the magnificent Henderson Lake and the Preston Ponds. It transferred most of the property to the state in 2008 but retained the core, 258 acres, for education and the preservation of historic structures.

The huge stone structure is a blast furnace. It was built between 1849 and 1853 and cost $43,000, the equivalent of well over a million of today’s dollars. Built of large blocks of locally quarried anorthosite and sandstone reinforced with iron tie rods and anchors, the New Furnace was the last gasp of the Adirondack Iron and Steel Company, which had been trying to generate a profit from iron since its discovery on the remote headwaters of the Hudson River in 1826. The hardships of transportation to and from this nearly inaccessible site, along with impurities in the ore—mainly titanium, which is what NL Industries was mining here from World War II until the 1970s — doomed the enterprise.

The New Furnace, so called because it was the 4th one built here, was first fired in 1854 and operated for only two years. It was the center of an extensive industrial works, with mining, charcoal manufacture, two dams on the Hudson, saw mills, and a village to house the workers.

Raw ore was extracted from accessible veins and outcroppings by drills, hammers, and black powder. Small charges loosened the ore, which was then broken into chunks of roughly fist size. These chunks were then roasted in a brick kiln or in mounds over piles of wood to oxidize it and burn off some of the impurities.

The roasted ore was washed and then carted to the west end of the charging bridge, a wooden superstructure which led to the top of the furnace from the west; the high ground you see across the road from the furnace is where the charging bridge began. On the bridge the ore was crushed in drop stamps, heavy blocks of hardened cast iron. These were lifted 15″ by a cam shaft powered by a water wheel in the wheel house down on the river’s edge.

The crushed ore, along with charcoal and lime, in a carefully measured ratio, were then introduced into the furnace through the tunnel head at the top of the stack. At the height of activity, a new charge was introduced every 30 minutes. The charcoal, fired in brick kilns, was stored in two large sheds at west end of charging bridge.

The heat in the furnace was increased by blasts (hence the name “blast furnace”) of air blown by 4 cast-iron blowing cylinders in the wheel house powered by a 2nd water wheel (a timber-faced stone dam created an impoundment for a higher head and more power). These cylinders, along with many other assorted pieces of hardware are still lying on the ground next to the river. One of OSI’s aims is to protect them and explain their use to visitors.

The forced air was piped from the cylinders to the hot blast stove, a brick structure reinforced by iron rods on top of the furnace; there the air was heated by waste gases rising from the stack. Heated to around 500 degrees F, it was forced down to the hearth through a cast-iron pipe called a downcomer. Pushed at high pressure through cast-iron nozzles called tuyeres, the super-heated air enabled the furnace to reach temperatures of 2500 degrees F with 20% less charcoal than in a conventional furnace. The tuyeres had to be periodically cooled with water pumped from the river.

This technique of forcing blasted air originated in Great Britain and was used with anthracite coal; it was not originally designed for charcoal-heated furnaces. The shape of McIntyre internal chamber was also designed to be more like a coal-fired than a charcoal-fired furnace—wider at the bosh, or widest part, of the chamber. The innovative adoption of smelting techniques designed for burning anthracite made this charcoal-burning furnace an important milestone in the history of American technology.

At the bottom of the furnace, at the base of the hearth arch on the river side, was a channel, which led to the casting house, where molten iron ran into sand molds (or pigs) for cooling. These channels were opened up about twice a day. Once cool, the pig iron was ready for shipping. The casting house was a wooden shed between the base of the furnace and the river. From a wharf at the river’s edge, pigs of refined iron were hoisted by crane onto boats, for the trip down Sanford Lake to the Lower Works, where there was another wharf and crane.

At the Lower Works was a second dam which raised the level of Sanford Lake 6 to 8 feet to enable this traffic. From Lower Works, iron was loaded onto wagons for the journey to Lake Champlain. The route was via the Cedar Point Road, which ran from the docks at the south end of Sanford Lake to Port Henry on Lake Champlain. The ultimate destination was the company’s steel works in Jersey City, NJ.

After 1855, the New Furnace was never fired again. Both dams — at the New Furnace and Lower Works – were destroyed by flood in 1857.

Workers at the furnace endured conditions almost unimaginable today: When fired, the furnace operated 24 hours per day, probably with only two shifts, and generated heat at the hearth of 2500 degrees F. In the winter, temperatures just a few feet away could be 30 degrees below zero. Smoke, soot, ash, molten iron, moving parts in the Wheel House, and long hours made for dangerous, grueling labor.

There are many important sources for the history of this site, nearly all conveniently and invaluably assembled in two volumes by Lee Manchester:

Tales from the Deserted Village: First Hand Accounts of Early Explorations into the Heart of the Adirondacks and Annals of the Deserted Village: Key 20th Century Studies of an Emblematic Adirondack Settlement. The essential text for understanding how the furnace worked is a 1978 report, with useful drawings, to the Historic American Engineering Record by Bruce E. Seely, “Adirondack Iron and Steel Company: ‘New Furnace,’ 1849-1854,” included in Manchester’s Annals of the Deserted Village.

Photo: The New Furnace, c. 1885, showing the charging bridge still standing. Photograph by Seneca Ray Stoddard provided by the Adirondack Museum.