Bennett, J. and Johnston, S., The Geometry of War, 1500-1750 (Oxford, 1996)
69. An ivory rule, smaller than catalogue no. 68, but very similar in content. In fact the rule, protractor, fortification diagrams and tables are all equivalent, and similarly disposed between 'INTRORSUM' and 'EXTRORSUM', except that this rule has an additional diagram with an accompanying key marked: 'Pro Alis Fortificandis', giving the names of the various parts in French and, in one case, the function: 'Triangle qui couwa les Canons Cachè.'
Length: 152 mm
Inventory no. 33,529
Other narratives:
- Inventory no. 33529 - Former Display Label
- Article in Museum Publication : Sphaera No. 4 (Autumn 1996) Extract from 'Fallout from the Geometry of War'