ESHS/HSS Annual Meeting

Bringing Greenwich to Sobral: Craftsmanship and Instrumentation on the 1919 Solar Eclipse Expedition

• In Event: Emerging from the Shadow: New Perspectives on Solar Eclipse Expeditions 2

English Abstract

In 1919, two solar eclipse expeditions provided the first support of Einstein’s theory of relativity. Although widely praised at the time, historians later argued that the expedition had wrongfully discarded data. In this paper, I revisit the 1919 solar eclipse expedition to Sobral, Brazil, through the lens of a neglected actor: Charles Davidson, a technician at the Royal Observatory, Greenwich. Drawing on novel archival materials, I reconstruct Davidson’s training in photography, repair and instrument maintenance, both at Greenwich and in the field, and his deployment of those skills in 1919. My portrayal of Davidson is situated within an account of changing conceptions of observatory technicians and demonstrates that local practices developed at Greenwich through the Carte du Ciel and previous solar eclipse expeditions were central in 1919. Finally, I contribute to the debate around the controversial exclusion of the Sobral Astrographic’s photographs. My work underscores the centrality of materiality, repair-work and (in)visible technicians in science.

Author

• Rebecka Mikaela Mähring