Valve blueprint
*On this date in 1892, a Black man received a Valve patent. Machinist and union activist Frank J. Ferrell was the inventor; his patent number was 467,796.
Created Equal: The Lives and Ideas of Black American Innovators
By James Michael Brodie
Copyright 1993, by Bill Adler Books, Inc.
William Morrow and Co. Inc., New York
ISBN 0-688-11536-5
