Speaker
Description
By the late nineteenth century, the Bologna Observatory, housed in the eighteenth-century Specola Tower, had entered a period of decline due to structural constraints and the increasing effects of urban light pollution. A decisive turning point came in 1936, when the Observatory was transferred to Loiano under the direction of Guido Horn d’Arturo (1879-1967), who equipped the new site with a 60-cm reflector featuring a monolithic mirror manufactured by the Zeiss workshops in Jena, marking Bologna’s return to the forefront of Italian astronomy.
Horn d’Arturo’s institutional and cultural contributions extended well beyond this: he founded Coelum (1931), the first Italian journal devoted exclusively to the popularisation of astronomy; he reorganised the Observatory library; and he carried out the first systematic reordering of the Historical Archives of the University of Bologna’s Department of Astronomy.
His scientific work ranged from positional astronomy and variable stars to optical phenomena and the physiology of vision. He is best known for developing the tessellated mirror, a technology now employed in major astrophysical facilities. Despite his prolific output, however, he published almost exclusively in Italian, a circumstance that contributed to the limited international reception of his work.
Drawing on published sources, archival materials, and surviving instruments preserved at the Specola Museum of Astronomy, this paper explores Horn d’Arturo’s role in a crucial moment for the scientific and institutional development of Bologna astronomy. The contribution is presented on the occasion of the ninetieth anniversary of the Loiano Observatory and the tricentenary of the Specola.