Fig. 66.—Vauban's Outwork.
[Fig. 66] presents on a larger scale the plan of the outwork constructed by Vauban. Before the three fronts of this work, demi-lunes with tenailles behind defended the approaches.
Four barracks were built at a. Cavaliers arose on the bastions, and the covered ways, with their places d'armes, were furnished with traverses. In the event of this work being taken, the main body of the fortress could still hold out some days.
[Fig. 67] gives the sections of these works, which were cased with masonry, presenting a strong defence which only a regular siege could affect.
Fig. 67.
But it is desirable to point out the reasons that determined the plan of this work, and the method adopted by the illustrious engineer.
Vauban fortified according to the nature of the position, and was not one of those esprits routiniers who, when once a certain system has made good its claims, insist on applying it on all occasions.
The fortresses, which, like that of La Roche-Pont, are situated at the extremity of a promontory and present only a narrow front to the besieger, assuredly give certain advantages to the defence, since they have scarcely to fear more than one attack and are accessible only on one side; but this position is not without its drawbacks, especially if, as in the present instance, a fan-shaped plateau spreads outside the fortress; for then the besiegers sweep the defences with converging fires, to which the besieged can oppose only a narrow front unprovided with considerable flankments. On the east side the large bastion, in the middle of which Vauban had left standing the fifteenth-century tower, which thus gave him a good revetted cavalier, sufficiently flanked the eastern brow of the outer plateau; but on the western side such a flankment failed entirely, on account of the outward bend caused by the promontory. To obviate these disadvantages Vauban inclined his capital some paces eastwards.[See [Fig. 65].]