A Furnace for Arms–January 2, 1776

The Mount Riga Ironworks Furnace in Salisbury, CT. There was more than one furnace at this location; this is the surviving one. It’s on the National Register of Historic Locations and a lovely place to visit if you’re in the northwest corner of the state. The Mount Riga Iron Furnace isn’t an especially unique artifact on the east coast of the US. In fact, as someone who lives in Baltimore, I get to see one of them regularly when I visit my mother-in-law, who lives about a half-hour’s drive away in a more rural part of the state. Unfortunately, that one (the Northampton Furnace is in bad shape because of its location close to a modern-day reservoir, so it’s in the water a lot of the time. But it got me curious enough to wonder what they did, and how they worked. In the oversimplified version, you layer the iron ore and limestone, along with the fuel, usually charcoal or coke, into a tall stack. Once the fire is lit, air is pushed into the bottom and forced upward, creating superheated air which gets it to about 4000 degrees. The ore melts down and the limestone collects the impurities in the ore. The limestone and impurities float to the top as slag, and the molten iron can be removed as pig iron. This is the raw material for making iron and (later on) steel. (Steel did exist in the 18th century, but it would be nearly 100 years before Henry Bessemer came up with the mass production process that made the Industrial Revolution possible.) Iron furnaces aren’t unique, but they’re not especially common either, so it was important in the Revolutionary Era to locate them and ensure that they were adequate for creating the raw materials for producing weapons. The post A Furnace for Arms–January 2, 1776 appeared first on 250 and Counting.