Claude
The cachet features a detailed black and ink illustration of Albert Einstein with mathematical equations on a blackboard behind him (including E=MC² and relativistic mass formula), alongside a small vignette of Princeton University. Text identifies him as 'Father of the Special Theory of Relativity, the basis for the development of atomic energy.' The stamp is the 15-cent Einstein USA commemorative issue in brown/purple tones showing Einstein's portrait in profile. The pictorial cancellation reads 'AEROSPACE / MILCOPEX 1979 / MAR 4 1979 / MILCOPEX STA., MILWAUKEE, WISCONSIN 53201' and features stylized jet aircraft with stars and streamlines.
Mistral
This First Day Cover features a detailed cachet by GAMM with a portrait of Albert Einstein in black and white, accompanied by mathematical equations related to his theory of relativity. The stamp is a 15-cent commemorative issue depicting Einstein in brown. The cover is cancelled with a pictorial postmark featuring an aerospace theme with stars and trajectories, dated March 4, 1979, from Milwaukee, Wisconsin. The cover is in excellent condition with clear and legible prints.
(The automatic summaries sometimes misidentify the postmark as part of the cachet artwork.)
