Enfilade

From the University of Michigan:

The Geometry of War: Fortification Plans from Eighteenth-Century America
William L. Clements Library, University of Michigan, 15 October 2012 — 15 February 2013

The eighteenth century was a time of intensive military activity in Europe and in the Americas. Much of this centered on fortified towns or positions. The period from the 1680s to the French Revolution has been called the “classic century of military engineering,” a time when earlier forms of artillery fortifications were perfected and frequently tested in battle.

Designing, constructing, and recording fortifications was the job of the military engineer. He followed well-tested principles of design, based on geometry, to construct fortified places. These were recorded in detailed plans, many of surprising beauty and complexity. The Clements Library is rich in examples, manuscript and printed, and offers a sample illustrating the science of fortification in eighteenth-century America.