Original oil and gas trade magazine vintage ad for THE WILLIAM POWELL COMPANY of Cincinnati, OH. Turnings. Shavings off a Wm Powell valve just after machining. Powell control valve was specialty made of silver, almost 100 percent pure silver, needed to overcome problems of product contamination in the manufacture of pharmaceuticals and photographic supplies. This unique 1962 oilfield petroleum well industry equipment magazine advertisement would display beautifully matted and framed.