This was his idea of a fortified town: "It ought to stand in a plain, its citadel commanded by no eminence. The rampart-wall should be three paces wide at base, supporting an earthern rampart of fifteen or twenty paces wide, with barbicans. This retaining wall should be in height about twenty feet, and have above it a curtain of nearly as many. The upper part, being most exposed to be battered, had better have an earthen facing. There ought to be a platform, rising sixteen feet over the curtain, placed half-way between each baloard and bastion. The baloards should have guns mounted only at the sides, and be of massive strength, from fifty to sixty paces in diameter, that the guns may be freely wrought. Should a baloard be taken, it will still be flanked by the adjoining platforms, a ditch drawn between each of which would in a night's time recomplete the defences. The fosse should be about twenty paces wide, and is best without water, so as to allow artificial fire to be showered down upon the enemy. There ought to be no counterscarp, seeing it generally serves as a protection to the besiegers; but, if there be one, it had better be only of earth, at a low angle of elevation. Above all, there ought to be provided many secret ports for frequent sallies, and for the easy return of the men. It has been long noticed that no fortress was ever carried but by some oversight of its defenders, and everything depends upon a judicious selection of positions for defence. Unquestionably a single sin suffices to send a man to the devil, whatever be his other good works; and, in like manner, one oversight in fortification may lose the place, as happened when I took Pavia and Cremona. In short, it is all very well to play with plans and models, but one must see to everything on the spot." "He said, in reference to the fortresses of Legnano and Verona, that it was very ill-judged in the Republic never to carry things out as they had been planned, in consequence of frequent ministerial changes, and the system of governing from day to day, and bit by bit, without reference to any general design. By adopting an opposite method, he had completed the defences of Pesaro much more efficiently, and at a third of the outlay it would have cost any one else, simply because he was the sole head and executor, and kept in view the entire works, not the individual gates, baloards, and details; and by so completing them that it must be attacked on two or three sides, whilst provided with ten or twelve concealed sally-ports." He contended that a fortress on a hill was difficult to defend, one on a plain less so; but that the easiest and most secure was one whose defences partly extended along the level, and in part rose upon steep ground, such as Verona, which he maintained could be more easily held by five thousand men against eighty thousand, than most towns by eight thousand against half that besieging force.