PITTSBURGH PLANT—NATIONAL FIRE PROOFING CO. 
Chis Plant Covers About Six Acres, Located Directly in the City of Pittsburgh, Within Ten Minutes’ Walk of the Allegheny 
County Court House. To the Right is the Allegheny River and to the Left Bedford Avenue. In the Foreeround 
is the Clay Pit and to the Right of the Picture is Shown the Clay Ledge 
Baltimore. Md. Works, American Refractories Co.