17th century

  Fig. 88          Fig. 89

A German rule, shaped, pierced and decorated at one end, and bearing the monogram 'AF'. Both surfaces of the flat rectangle are crammed with tables and scales relevant to military architecture, recognising the different systems of three military engineers: 'Freytag', 'Vavban' and 'Klengel'. There is, for example, an extensive table of the sectional elements of a fortification, with the elements named and their proportions given for each system, as well as scales for setting out regular polygons. A.V. Simcock has suggested that 'AF' could be Adam Freitag, author of Architectura militaris nova et aucta (Leiden, 1631), whose system is included among those covered by this rule.

Length: 193 mm

Inventory no. 49,349