Page:Ware - The American Vignola, 1920.djvu/38

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DRAWING General Proportions.—Since the relative size of all " the parts, in Vigriola's Orders, is fixed, any of them can be drawn out in accordance with these rules, if a single dimension is determined. The width of a Dentil or the length of a Modillion suffices to determine everything else. But the data generally given are either the lower Diameter of a Column, the height of a Column, or the whole height of the Order, with or without a Pedestal.

I. If the lower Diameter is given, the procedure is as follows, Fig. 96: Divide it in two, draw the axis of the Column, and then divide each half into three equal parts, Fig. 109; this gives the scale of sixths. Divide in two the two Outer sixths; this gives the upper Diameter of the shaft, which is five-sixths. Lay off on the axis the height of the Column by Diameters, 7, 8, 9, or 10 and of the Entablature, which is one-fourth the height of the Column. Mark the height of the Base, half a Diameter, or three-sixths, and then that of the Capital, two-, three-, or seven-sixths.

Then divide the total height of the Entablature into seven, eight, eighteen, or ten equal parts, according as it is Tuscan, Doric, Ionic, or Corinthian, or use halves, quarters, or eighths of a Diameter, and mark the heights of the Architrave, Frieze, and Cornice, drawing horizontal lines through the points of division. (Fig. 96 illustrates this procedure for the Tuscan Order.) Then carry up, vertically, the outer lines of both the upper and the lower Diameters of the Shaft, drawing from the point where the line of the upper Diameter cuts the lower edge of the Cornice a line at 45 degrees to determine the projection of the Cymatium, or, in the Doric Orders, that of the Mutule or of the Corona.

Add one-third of the height of the Column for the Pedestal. Divide this into three equal parts, taking the upper third of the upper third for the Cap, and the lower two-thirds of the lower third for the Base, Fig. 96. Vignola makes the Base of the Pedestal only one-ninth of the height of the Pedestal instead of two-ninths as here determined.

II. If the height of the Column is given, a fourth part of this added at the top gives the height of the Entablature, and a third part added below gives the height of the Pedestal, Fig. 96. One seventh, eighth, ninth, or tenth of the height