FOURTH

And because the Architect must be rich in invention to satisfy himself and others, one may also adorn the gate of a city or fortress in this alternative manner. One must observe this rule: that however wide the opening of said gate shall be, its height shall be a sesquialteroriginal: "sesquialtera"; a ratio of 1:1.5, or 2 parts width to 3 parts height—that is, two parts in width to three in height. Its pilaster-strip should be one-eighth part of the width of the gate, and the column should be one-fourth part of that same gate. But because the column is one-third part embedded within the wall—bound with the other stones and placed more for ornament than for supporting weight—it shall be made seven parts in height; it could even allow for eight in such a case, should the Architect wish to make the gate more slender.

The opening of the side gates shall be half that of the main gate, and their pilaster-strips shall be like those of the large one. Its height shall be such that the band supporting the arch serves as its linteloriginal: "supercilio o architraue"; the horizontal beam or "eyebrow" spanning the top of the door, or architrave, whichever we wish to call it. And if a stone of a single piece cannot be found for such a need, let the voussoirsoriginal: "cunei"; the wedge-shaped stones that form an arch or lintel be made as illustrated. Thus, the proportion of these gates will be five-to-threeoriginal Latin: "superbipartiens tertias"; a ratio of 1 and 2/3, which is 5:3, that is, three parts in width and five in height. The voussoirs of the arch shall number fifteen. In the bases, capitals, architrave, frieze, and cornice, the rule given for the first column should be observed; likewise, the central elevation shall be at the Architect's discretion, as has been said of the others. The more roughly such works are hewn referring to the "rusticated" or unfinished look of the stone, the better they will serve the decorumoriginal: "decoro"; the principle that a building's style should suit its function of the fortress.