The Rare Traces of Constructional Procedures in `Practical Geometries´

From a sociological point of view, pre-Modern "non-theoretical geometry" is not adequately described as merely "practical". The "practical geometry" we find in written treatises is mostly that of "scribal" environments, and aims at calculating lengths, areas or volumes from already performed measurements. As a rule it is not interested in geometrical construction, nor in the making of measurements - the fields, broadly speaking, of master builders/architects and surveyors.

The paper discusses two cases - one fairly well-established, another more conjectural - where none the less "scribal" practical geometry does reveal traces of (very simple) geometrical construction. Both of these concern the "long run", connecting Old Babylonian, classical ancient and late medieval material. A final instance of weak communication between "scribal" and "surveying" geometry is located in thirteenth-fourteenth-century France.