This open access volume focuses on the cultural background of the pivotal transformationsof scientific knowledge in the early modern period. It investigates the rich edition history of Johannes de Sacrobosco’s Tractatus de sphaera,by far the most widely disseminated textbook on geocentric cosmology, from the uniquestandpoint of the many printers, publishers, and booksellers who steered this text frommanuscript to print culture, and in doing so transformed it into an established platformof scientific learning.The corpus, constituted of 359 different editions featuringSacrobosco’s treatise on cosmology and astronomy printed between 1472 and 1650,represents the scientific European shared knowledge concerned with the cosmologicalworldview of the early modern period until far after the publication of Copernicus’ Derevolutionibus orbium coelestium in 1543. The contributions to this volume show how the academic book trade influenced theprocess of homogenization of scientific knowledge.They also describe the materialinfrastructure through which such knowledge was disseminated, and thus define thepremises for the foundation of modern scientific communities.