pair of hard to find and highly sought after early 1870's american victorian era solid bronze interior residential doorknobs. the hexagonal-shaped ornamental bronze passage door handles exhibit a nicely aged surface patina. the casting detail is crisp, with very little wear evident. visually striking design featuring very elaborate scroll work. the doorknobs were designed and patented by charles kunze for the metallic compression casting company. lightly incised manufacturer markings found on the backside of each doorknob. the metallic compression casting co. manufactured "house trimmings", such as knobs, hinges, escutcheons, bell pulls, along with dies for printing wall paper, and for bookbinders, and a variety of articles. the inventions of charles and michael smith, introduced with complete success into practical operation by the metallic compression casting company at their foundry in bomerville, near boston, revolutionized metallurgic art, so far as casting is concerned. by employing the patented process developed by smith and mason, metal was taken from the mould, not with a rough surface, as in all the heretofore known modes of casting, but as smooth and perfectly finished as a coin or medal struck by a die. priced for the pair.