Chapter XVII, Of the Corinthian Order
The Corinthian order, which is more beautiful and elegant than any of the foregoing orders, was first invented in Corinth, a modes noble city in Peloponesus.
The columns are like those of the Ionic order, being five modules and a half in height, including their base and capital.
................
The heigth of the Corinthian capital ought to be the diameter of the column below, and a sixth part more, which is allowed to be the abaco. The remainder is divided into three equal parts; the first is given to the first leaf, the second tot the second, and the third is again divided into two parts. In that part nearest to the abaco must be made the caulicoli or stems, with their leaves, that seem to be supported by them, and from which they arise; therefore the shaft or stem from whence they spring should be thick, and diminish gradually in their foldings, imitating thereby the plants, which are thicker in the part from whence they sprout, than at the extremities of their branches.
the campana, which is the body of the capital under the leaves, ought to fall directly perpendicular with the bottom of the flutes of the columns. To form the abaco, and to give it a suitable projecture, a square is to be made, every side whereof must be a module and a half, whitin which let diagonal lines be drawn, and in the middle or centre where they intersect, the fix'd point of the compasses ought to be placed, and towards every angle of the square a module is to be marked; then, where the points are, lines that intersect the said diagonals at rectangles must be drawn, so as to touch the sides of the square, and these will be the bounds of the projecture, the length of which also give the width of the horns of the abaco.
the curvature, or diminution, is made by drawing a thread from one horn to the other, and taking the point where the triangle is formed whose base is the diminution, then a line is to be drawn from the extremities of the said horn to the extremity of the astragal or tondino of the column, which line the tip of the leaves is to touch, or they may come out a little more, and this is their projecture. The width of the rose ought to be a fourth part of the lower diameter of the column.
..............