The conception of a mathematical instrument and its distance from the material world: the ‘Pantometra’ in Lisbon, 1638

At Lisbon in the 1630s a Jesuit of English birth, Ignace Stafford (1599–1642), wrote a thick treatise on calculating instruments, among them Gunter's sector, while he was a teacher of the 'Aula da Esfera' attached to the Society's college. Gunter had published his book on a sector equipped with recently developed logarithmic scales at London in 1623. While Stafford may have been the first person to routinely deal with logarithms on the Iberian peninsula, he does not seem to be the first one introducing the use of the sector. It appears that earlier versions of this instrument had some currency already under the name of 'pantometra'. This article is based on a close reading of Stafford's arithmetical treatise that seeks to make visible different kinds of distances in communicating knowledge, as well as the interplay of distancing and approaching. Paying attention to the various kinds of distances involved, will contribute to a better understanding of the historical contingencies that shaped this particular work on arithmetic and mathematical instruments. As a conclusion, I briefly consider the impact of varying distances on the circulation of knowledge.