This part consists of making gabions, fascines, hurdles, and sap-rollers; of tracing (part by night) parallels, approaches, batteries, etc.
Also of seeing parallels, approaches, batteries, saps, trench cavaliers, etc., constructed by the sappers; and the mode of extending men and setting them to work.
The officers are also required to take up for enfilade the prolongation of faces, etc.
Part III—Works of Defence.
This part consists of instruction in forming abattis, entanglements, rifle pits, trons-de-loup, etc., and in putting up stockades, palisades, fraises, etc.
Part IV.—Mining.
This part includes boring and blasting rock, sinking shafts, driving galleries, making chambers and powder hose, loading, tamping, and firing mines, also the preparation and firing of fougasses.
Part V.—Bridging.
This part includes knotting, splicing, and lashing spars, diving, rowing in boats, packing pontoons, and forming temporary military bridges over streams with large and small pontoons, casks, etc.
Also the construction of spar, timber, and suspension bridges to reëstablish a communication by turnpike road or railroad.