Pierre Jules César Janssen (1824 – 1907), also known as Jules Janssen, was a French astronomer who, along with English scientist Joseph Norman Lockyer, is credited with discovering the gaseous nature of the solar chromosphere, and with some justification the element helium.

François-Frédéric Boissonnas (1858 –1946), known as Fred Boissonnas, was a Swiss photographer from Geneva. His work is considered crucial for the development of photography in Greece, and its use in favorably publicizing the country’s expansionist ambitions, during the early 20th century. Boissonnas constitutes a central figure in the transition from 19th century approaches to a more contemporary photography of antiquities.