Algorismus: Hindu-Arabic Arithmetic in GKS 1812 4to

Abstract

The Old Norse treatise Algorismus is a prose translation of the Latin hexameter poem Carmen de Algorismo, written in France in the early thirteenth century by Alexander de Villa Dei (ca. 1170–1240), who was a canon at St. Andrew’s Cathedral in Avranches. The Old Norse translation exists in four manuscripts, one of which is GKS 1812 4to, preserved at the Árni Magnússon Institute for Icelandic Studies in Reykjavík. This translation is slightly extended by clarifications from the Icelandic writer on the original text. Furthermore, its content about drawing the cubic root seems to have enkindled association with ancient cosmological ideas, circulating in the medieval world, about the cubic numbers 8 and 27, associated with the elements of earth and fire, and further producing the numbers 12 and 18, representing water and air. This section about the elements is considered the only known incidence of a reference in Old Norse to the Timaeus of Plato, most likely derived from the Latin translation by Calcidius. The cosmological ideas seem also to be related to a theory on proportions, presented in the ancient textbook Elements by Euclid from 300 BC.