one of two original and well-preserved early 1870's heavy cast bronze metal exterior or entrance door size doorknob executed by metallic compression casting company, boston, mass./russell & erwin company, new britain, ct. the oversized ornamented doorknob features a banded edge with raised center accentuated with a deep relief central rosette. nicely aged surface patina left untouched. the knob was designed by john joseph charles smith for the metallic compression casting co., boston, ma. the design was patented on june 7, 1870. the maker markings are incised on the backside of the doorknob and along the shank. very little wear evident. dates to 1870-75. metallic compression 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. several doorknobs in this exact pattern are available.