Stamp, in black ink, stamped, on verso, centered: [stamp is in box shape] HAROLD E. EDGERTON | SEP 12 1961 | M.I.T. CAMBRIDGE, MASS. Stamp, in black ink, on verso, lower left: [stamp is in box shape with two palm trees on left side] © 1961 [61 in pencil] Estate of | [in pencil] 10.069 | HAROLD E. EDGERTON.
Inscribed, in pencil, on verso, upper right corner: 10.069 [boxed].