CHAPTER IV¶
On Round Columns with Their Bases, Capitals, and Pedestals or Stylobates, and How the Corinthian Capital and Its Four Tetrants Are Constructed.
Wishing to give you concisely all that is needed for round columns (colonne rotonde, depicted in full on Plate 0213), I divide this treatment into two parts: first the column with its base and capital, and second its pedestal or stylobate (stilobata ouer pilastrello).
1. Origin of the Names Ionic, Doric, and Corinthian, and Comparison with the Attributes of Christian Saints
So that the unfamiliar Greek names in Vitruvius—Ionic, Doric, and Corinthian—may cause no obscurity in your minds, know that the Ancients named these three species of columns after the lands and peoples where they were first invented: the Ionic from the Ionians, the Doric from the Dorians, and the Corinthian from the Corinthians (just as in Roman history the Fabii and fabae [beans], or Appius and appiae [apples], took their names from one another).
And to understand why the Ancients varied the strength and ornament of their columns and temples according to the gods to whom they were dedicated, consider what we ourselves do in our Christian religion: to every Saint we assign the particular emblems and instruments by which they fought for the holy faith—to St. George, full armor, lance, cuirass, helmet, sword, and horse (and likewise to St. Maurice, St. Eustace, and the Maccabees); to St. Catherine, the wheel whereby she was crowned with martyrdom; to St. Barbara, the tower in which she was imprisoned (quoniam verbera carnificum non timuerunt sancti Dei). In the very same way, the Ancients, according to their pagan rites, fashioned sturdy, unadorned Doric columns for Hercules, Mars, and Jupiter, graceful matronly Ionic columns for Diana and Juno, and slender, flower-crowned Corinthian columns for Venus, Flora, and the Nymphs!
Proportional Construction of the Corinthian Capital and Its Abacus (Plate 0213)
Height of the Abacus (:math:`frac{1}{8} - frac{1}{10} = frac{1}{40}` of the Column Height): To proportion the capital of the round column (see Plate 0213), the Ancients first divided the total intended height of the column (including its capital) into 8 equal parts (\(\frac{1}{8}\)), and then divided that same height into 10 equal parts (\(\frac{1}{10}\)). Subtracting one-tenth from one-eighth leaves one-fortieth (\(\frac{1}{8} - \frac{1}{10} = \frac{1}{40}\)) of the total height!
This fortieth part (\(\frac{1}{40}\)) is assigned to the thickness (height) of the abacus (abaco, called cimatio by modern masons, marked \(ln\) or \(mo\) in Plate 0213).
The tenth part (\(\frac{1}{10}\)) below the abacus forms the bell or drum (la campana ouer tamburo, also called caulicolo) of the capital down to the upper necking (gola ouer contractura superiore) of the shaft, marked \(lg\) or \(mh\).
Volutes (*Voluti*), Tetrants (*Tetranti*), and the Eye (*Ochio*) of the Capital:
At the four upper corners of the bell beneath the four horns (corni / anguli) \(l, m\) of the abacus spring the scrolling volutes (voluti).
The span from one corner horn of the abacus to the next (\(no\)) is called a tetrant (tetrante), so that every capital has 4 tetrants on its four sides; and in the middle of each tetrant is carved a rosette, flower, or leaf (fiorone o rosa), called the eye of the capital (ochio del capitello).
Geometric Rule for the Plan and Curvature of the Abacus:
Take the diameter of the lower necking (contractura de sotto, at the base of the shaft), double it (\(2\,d\)), and make that doubled length the diagonal of a square inscribed in a circle!
That square is the exact plan of the abacus of the capital.
Then curve each of the four sides (tetranti) of the square inward toward the center by one-ninth (\(\frac{1}{9}\)) of the side of the square, forming the graceful concave sweep of the abacus up to the central rosette (ochio) on each face!