A Newly Discovered Ethnocultural Substrate along the Atlantic Façade—Evidence for the Unique Counting System and Mathematical Strategies Shared by the Basque Country (Euskal Herria), Spain, France, Ireland and Scotland

Until now, the pre-decimal metric units of linear measure employed traditionally in the Basque Country have not been compared to similar ones documented for Celtic-speaking zones of the Atlantic façade. These base units are distinctive in that they are septenary in nature, consisting of units of seven and its multiples. In this study, the remarkable similarities that characterize these traditional linear measures are analyzed and subjected to scrutiny. The investigation also examines the mathematical strategies that were involved in laying out land holdings. The measuring devices traditionally employed are also discussed, as well as the ways in which the septenary units acted to structure sociocultural, political and administrative practices. The implications that can be drawn from the wide geographical reach of the system are explored, along with the time-depth that should be assigned to the system as a whole.