This study offers a detailed analysis of an episode of the popularization of astronomy which took place in Portugal, a peripheral country of Europe, and occurring in the early twentieth century. The episode was driven by the 28 May 1900 total solar eclipse which was seen on the Iberian Peninsula (Portugal and Spain). Instead of focusing on one of the ends of the popularization process, we analyze the circulation of knowledge among scientists and the public, contrast the aims of the various expeditions, professional and amateur, which took place on Portuguese soil, analyze their repercussions in the Portuguese astronomical landscape, and the different ways used by the Portuguese political elite and astronomical community to successfully appropriate this astronomical event to serve their varied agendas, political, social and scientific. In this episode of public enthusiasm for science, a central figure emerged in the network of the official commission, professional and amateur communities and the "general public": Frederico Tomas Oom (1864-1930), an astronomer of the Lisbon Astronomical Observatory. This paper aims to illustrate the different layers of the circulation process, and at proving that the popularization of science was not a unidirectional process from scientists to lay people nor did it serve only a particular agenda, be it political, social or scientific. (Contains 5 figures and 103 footnotes.)