Were there leg irons manufactured using the 1862 Adams patent style shackle (precursor to Tower)? If so, could someone perhaps post a picture of the same? I'm working on a little project regarding antique leg irons and want to make mention of the Adams design.
Thanks,
Franklin
Hi AC:
Because of the date of manufacture, your bottom key Towers are almost certainly made of wrought iron, as are the pictured Adams. The first foundry in the US that produced modern steel using the Bessemer process was built in 1866, but it took over a decade for it to become firmly established in the marketplace.
The typical patina color for wrought iron is black, which is not iron oxide (rust) but an oxidation of the silicates, phosphorus and other trace impurities contained in wrought iron, but not present in modern iron smelted in a blast furnace or open hearth which burns away all impurities to produce virtually pure iron.
That black patina provides a natural rust protection to wrought iron similar to the bluing you see on firearms. Regretably, the whole subject of wrought iron versus modern steel is vastly misunderstood today and trying to correctly explain it is far beyond a simple post here. The project I mentioned in my first post is a website I'm putting together that discusses wrought iron and blacksmithing techniques and uses that as a means for identifying and authenticating antique fetters and manacles dating from Roman times through the 19th century when factory mass production of restraints began. I'm in the process of working on the photos and illustrations and hope to have the thing finished within the next year or so.
Franklin
