Parrotts were manufactured with a combination of cast and wrought iron. The cast iron made for an accurate gun, but was brittle enough to suffer fractures. Hence, a large wrought iron reinforcing band was overlaid on the breech to give it additional strength. There were prior cannons designed this way, but the method of securing this band was the innovation that allowed the Parrott to overcome the deficiencies of these earlier models. It was applied to the gun red-hot and then the gun was turned while pouring water down the muzzle, allowing the band to attach uniformly. By the end of the Civil War, both sides were using this type of gun extensively.
Parrott Rifles were manufactured in different sizes, from 10-pounders up to the rare 300-pounder.<ref... Read More