center verso typed on label: 186. Harold E. Edgerton: / Swirls and Eddies of a / Tennis Stroke, 1939; center verso in blue felt tip pen: (DO NOT KEEP); lower left verso in blue felt-tip pen: (Tennis Swing); lower center verso: Edgerton Estate stamp; lower left stamped in blue ink: H.E. EDGERTON / M.I.T. 4-405 / CAMBRIDGE-MASS.; by later hand, lower right in graphite: PP169
The Harold and Esther Edgerton Family Foundation; gift to NGA, 1996.