c. 1920's american vintage industrial cast iron steam valve stem bonnet salvaged from the boylston factory located in chicago, il. the uniquely shaped valve component can be used as table centerpieces, lamp bases, bookends, coin change or business card trays, etc. the steam valve bonnet was designed and fabricated by the boylston steam specialties co., chicago, il. measures 8 1/2 x 7 1/2 inches.