four matching original salvaged chicago antique american "mushroom" style white opalescent doorknob sets

group of four original 19th century white opalescent glass "mushroom" shape salvaged chicago mansion doorknobs likely fabricated by the nashua lock co., nashua, nh. each doorknobs contain a tapered or "stepped" shank comprised of bronze, with bathroom door knobs having nickel-plated finish. standard steel spindles included. the four sets of doorknobs were salvaged from a chicago italianate residence built shortly after the great chicago fire. each doorknob measures approximately 2 1/4 inches in diameter. priced for the lot.