original c. 1900-20 early industrial antique american made four-legged factory or drafting room adjustable height stool designed and fabricated by the johnson chair company, chicago, il. the reinforced oak wood stool contains multiple horizontal stretchers for added support and stability. the intact cast iron cradle housing the solid steel threaded spindle is affixed tightly to the outswept legs. the circular-shaped solid oak wood swivel seat is in good overall condition, considering age. the nicely aged surface patina has been left untouched.