pair of original and nicely aged early 1870's heavy cast bronze metal interior doorknob escutcheons executed by metallic compression casting company, boston, mass./russell & erwin company, new britain, ct. the two ornamented doorknob backplates feature elegantly designed floral motifs surrounding sunburst rosettes. the backplates were likely designed by john joseph charles smith for the metallic compression casting co., boston, ma. the design was patented on june 7, 1870. 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 backplates in this exact pattern are available. priced for the pair.