Fig. 65 presents the general plan of the works laid out by Vauban. At first he had thought of making on the north, before the front fortified by Errard de Bar-le-Duc, a horn-work before a demi-lune; but he could not thus effectually sweep the divergent points of the plateau. He determined, therefore, on the plan given in Fig. 65, making use of a part of the northern revetments of Errard de Bar-le-Duc. In advance of the northern front, in lieu of the narrow and contracted defences of Errard,[57] he made a great demi-lune, A (Fig. 65), with a tenaille behind, and next the bastioned work, B, which swept the whole plateau. As to the rest of the town, making use of the old bastions, he strongly flanked them and disposed the stronghold as shown by the plan, D. The roads of the upper town were widened and improved, and the houses detached from the ramparts. The ancient bridge at C had been destroyed by a swelling of the river, and was not rebuilt; but at P, in 1675, a new stone bridge was built, with a _tête du pont_ of earthwork. At O a foot-bridge still existed in 1680. The town had again extended along the left bank, and the importance of the _cité_ above was diminishing. [Illustration: 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. [Illustration: 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.