b. The main ditch, dry, wet, and dry or inundated at pleasure; sluices, coffer-dams, reservoirs.
c. Outworks. Ravelin, tenaille, counterguards, cover-faces, envelopes, tenaillons, lunettes.
d. Advanced works. Simple and double tenaille; horn-work before a bastion or redoubt; crown-work; double crown-work; advanced ditch, with advanced covered way.
e. Detached works, open or inclosed at the gorge.
f. Interior works. Cuts inside the bastions; réduits; citadels.
6. Historical notions of the characteristics of some of the principal systems of fortification, e.g. the old and modern Italian, the old Dutch, Vauban’s second and third manner, the ideas of Coehorn, Rimpler, the French school, and that of Montalembert, compared with Vauban’s first system, but without statement of proportions; in addition to this, the characteristics of the latest Prussian fortifications, always with the omission of details more especially technical.
7. Modified methods of attack; surprise, assault, bombardment, blockade; explanation and statement of circumstances in which attacks of this kind are practicable.
IV. SURVEYING AND DRAWING PLANS.
1. Knowledge of the instruments generally employed in military surveying, and their use.
a. Instruments for measuring and marking out straight lines;