In the wars of Napoleon there are innumerable instances in illustration of the delays and disasters attending the operations of armies not supplied with engineer troops; and, on the other hand, the advantages resulting from their services when properly organized and instructed. We have already pointed out the influence which the fortifications in the hands of the French exerted on the results of these wars, and the fatal consequences to the Allies of neglecting these works of national defence. Every student of military history will immediately call to mind the influence of Savona, Coni, Mondovi, Ceva, Govi, Alessandria, Tortona, Pizzighitone, Peschiera, Mantua, Palma-Nuova, Osopo, Klagenfurth, &c., in the campaigns of 1796-7; of Genoa, Port Bard, the fortifications of the Var, Ulm, Ingoldstadt, &c., in 1800; of Milan, Turin, Mantua, Roco d'Aufo, Genoa, Alessandria, &c., in 1805; the importance of Kehl, Cassel, Wesel, &c., to the French in 1806, and the fatal consequences to the Prussians in that campaign, of their total and culpable neglect of their own fortifications. All military historians speak of the influence of fortifications in the Peninsular campaigns: those which had been given up to Napoleon previous to the opening of hostilities, contributed very much to the success of his arms, while those which were retained by Spain and her allies, contributed in an equal degree to hamper and embarrass his operations. Some of these, like Saragossa and Tarragona, with their broken walls and defective armaments, kept the enemy in check some sixty days each, and did much to weaken the French power in the Peninsula. Temporary or field-fortifications also had an important influence here. The lines of Torres-Vedras, the field-works of Ronda, the intrenched camps of the Pyrenees, Bayonne, Toulouse, &c., are examples under this head. In fact, field-works played a most important part in all of Napoleon's wars. We might mention the redoubt of Montenotte, the intrenchments at Milesimo, the batteries of Lobau, the field-defences of Hougomont, La Haye-Sainte, and Papelotte at Waterloo, and numerous other cases equally striking. Just before the battle of Waterloo, Wellington employed some eighteen thousand peasants and two thousand horses, under the direction of British officers of engineers. In speaking of these defences, Colonel Pasley says: "It may be easily conceived that to have directed such a great body of workmen to proper advantage, by means of a few officers of engineers, would have been impossible, but for the system adopted of subdividing the various works among the non-commissioned officers and privates of the engineer troops, each of whom was made responsible for laying out the details of his own portion, and for the direction of a party of from twenty to one hundred men, or even more, according to circumstances."