Descriptions and Images of the Early Medieval Latin Abacus
Descriptions and Images of the Early Medieval Latin Abacus

Summary/Abstract: This paper deals with the abacus of the Latin pre-scholastic Middle Ages. According two descriptions of the abacus written around the year 1000 (one from the third book of the “History” written by Richer of Reims and the other from the first book of the “Liber Abaci” written by Bernelius the younger from Paris) and mainly according nine images of the calculating tool preserved in manuscripts from the end of the 10th to the beginning of the 12th centuries (so called abacus from Echternach and the abacus from Bern – either from the end of 10th century; the abacus from Paris from the beginning of 11th century; abacus from so called pseudo-Boethius’s the “Geometry II” from the half of 11th century; the abacus from Vatican, the abacus from Rouen and the abacus from Paris – all of these from the 11th century, the abacus from Oxford from the beginning of 12th century and so called abacus of Abbo of Fleury) this article presents in detail this arithmetic tool. The emphasis of this paper is given to the reconstruction of the form of this arithmetical tool according surviving images of this instrument as well as mutual comparisons of them together. This text focuses on the detailed description and analysis of the individual parts of the abacus (columns, arcs etc.) and furthermore presents and explains additional mathematical informations emerging in the mentioned images of the abacuses in manuscripts (for example abacistic symbols and names of numerals, markings of the abacus columns and symbols of fractions and relations between them).

• Details
• Contents