Despite recent work on scientific instruments by historians of science, the meeting ground between historians and curators of collections has been disappointingly narrow. This study offers, first, a characterization of sixteenth-century mathematical instruments, drawing on the work of curators, as represented by the online database Epact. An examination of the relationship between these
... [Show full abstract] instruments and the natural world suggests that the , familiar from studies of the history of astronomy, has a wider relevance to the domain of practical mathematics. This outcome from a study of collections is then used in re-examining an established question in the history of science, the position of William Gilbert on the motion of the Earth.