THE SEVENTH BOOK. (Book 7)
CHAP. I.
How Towns, or Castles are to be fortified.
YOU must understand that Towns and Castles are strong two ways, by Nature or by Art. They are strong by Nature which are encompassed by Rivers or Fens, (as Mantua, and Ferrara) or seated upon some Rock, or craggy Mountain (as Monaco, and Sanleo) for other places seated upon Mountains, if not difficult of access, are in our days rather weaker than otherwise, in respect of our Artillery and Mines: and therefore at present being to build a City, or erect a Fort that may be strong, we choose to do it in a Plain, and fortifie it artificially with Ramparts and Bastions, and our first care is to make the Walls crooked and retort, with several Vaults and places of receipt, that if the Enemy attempts to approach, he may be opposed and repulsed as well in the flank as the front: If your Walls be made too high, they are too obnoxious to the Cannon; if they be too low, they are easily scaled; if you make a Ditch before the VVall, to make the Scalado more difficult, the Enemy fills it up (which with a great Army is no hard matter) and makes himself Master immediately. My opinion therefore is this, (but with submission to better judgments) that to provide against both inconveniencies the best way will be to make your VVall high, and a Ditch on the inside rather than without; and this is the strongest way that you can build, because it keeps you both from their Artillery and assaults, and gives the Enemy no capacity of filling up the Ditch. Your VVall then is to be of the best height you can contrive; three yards thick at the least to resist their Batteries; it is to have Towers and Bulwarks at the distance of every 200 yards. The Ditch within is to be thirty yards broad at least, and twelve in depth; and all the earth which is taken out of the Ditch is to be thrown towards the