Cachet depicts a light beam passing through a prism to create a spectrum. Stamp depicts colors of the spectrum. The 15th Colloquium Spectroscopicum Internationale was held May 26-30, 1969 in Madrid, Spain.
|Place of publication|
|View in library catalog|
S.F.C., and Fábrica Nacional de Moneda y Timbre (Spain). “First Day Cover Commemorating the XV Colloquium Spectroscopicum Internationale.” Spain, 1969. Witco Stamp Collection, Box 5. Science History Institute. Philadelphia. https://digital.sciencehistory.org/works/08612n619.
This citation is automatically generated and may contain errors.