Part II · Chapter 1
The Anatomy of an Order
Pedestal, column, entablature and the module that binds them
An order, in the language of classical architecture, is a column together with the beam it carries, designed according to one of a small number of agreed systems. There are five: Tuscan, Doric, Ionic, Corinthian and Composite. Each has its own proportions, its own profiles and its own ornament, and each carries a character (sturdy or slender, plain or rich) that architects have used for two and a half thousand years to give buildings a voice.
The word itself tells us something. An order is an arrangement: it fixes not only the look of a column but the relation of every part to every other part, so that from a single dimension (the thickness of the column at its foot) the whole can be generated. This is why the orders suit a book like this one so well. The figure above is computed from a table of numbers, with a different set for each author.
An order consists of a column (base, shaft and capital) carrying an entablature (architrave, frieze and cornice), optionally raised on a pedestal (plinth, die and cap). Each part is proportioned to the lower diameter of the column.
order = [pedestal] + column(base, shaft, capital) + entablature(architrave, frieze, cornice)
Three parts, and three again
Read an order from the ground up. It may stand on a pedestal, itself a miniature building with a base, a plain block called the die, and a small cornice or cap. Then comes the column: its base, the long shaft and the capital. Above the column lies the entablature, which is again divided in three: the architrave, the frieze and the cornice.
These divisions are not arbitrary. The entablature is a stone memory of a timber roof. The architrave is the main beam laid from column to column; the frieze is the zone where the ceiling joists rested on it, and in the Doric order their ends are still represented as triglyphs; the cornice is the projecting eaves, whose overhanging corona throws rainwater clear of the wall. Vitruvius tells this story of carpentry turned into stone in Book IV, and whether or not it is literally true it explains a great deal about the form.
The module
Everything in an order is measured in modules. The basic unit is the lower diameter of the column shaft, written D in this book. Vitruvius, for the Doric, and Vignola, for all five orders, used half of it, the radius, as the module M, and subdivided it into twelve or eighteen parts for the details. A Vignola Corinthian column is thus 20 modules high, and its capital 2⅓ modules.
The module is what Vitruvius meant by symmetry: not mirror-image balance but commensurability, the property of being measured by a common unit. A building proportioned in this way can be built at any size and keep its character. When the text of this book says that the Ionic column is “nine diameters”, it means that whatever the size of the column, its height is nine times its lower thickness.
Architecture depends on order (ordinatio), arrangement (dispositio), eurythmy, symmetry, propriety (decor) and economy (distributio).
Vignola’s shortcut
Of all the systems, the one by Giacomo Barozzi da Vignola is the easiest to remember and was for three centuries the most used. Vignola gives a single rule for every order: the pedestal is a third of the column, and the entablature a quarter. Put another way, divide the total height into nineteen parts; give four to the pedestal, twelve to the column and three to the entablature. Without a pedestal, divide by fifteen. Only the column height, measured in modules, differs from order to order.
Divide the whole height into nineteen parts: four for the pedestal, twelve for the column, three for the entablature. Without a pedestal, divide it into fifteen, giving twelve to the column and three to the entablature.
pedestal = ⅓ column; entablature = ¼ column
| Order | Column (M) | Column (D) | Entablature (D) | Pedestal (D) |
|---|---|---|---|---|
| Tuscan | 14 | 7 | 1¾ | 2⅓ |
| Doric | 16 | 8 | 2 | 2⅔ |
| Ionic | 18 | 9 | 2¼ | 3 |
| Corinthian | 20 | 10 | 2½ | 3⅓ |
| Composite | 20 | 10 | 2½ | 3⅓ |
You can check the rule in the figure at the head of this chapter: switch on the labels and read the dimensions. Then switch the authority to Palladio or Scamozzi and watch the numbers drift. The disagreements between the authorities are the subject of a later chapter; the important point for now is that every author proportions every part to the same module.
The column and its shaft
A classical column is never a simple cylinder. Its shaft diminishes: it is thinner at the top than at the bottom, usually by a sixth. And the diminution is not straight but slightly convex (the curve called entasis), so that the shaft seems to swell gently under its load rather than pinch in at the waist, as a straight taper appears to do. Vignola’s method, used for every Renaissance column in this book, keeps the lowest third of the shaft cylindrical and curves the rest along a line found with a quarter-circle.
Keep the lowest third of the shaft cylindrical; above it, reduce the radius along a curve found by dividing a quarter-circle and the upper two-thirds of the shaft into the same number of equal parts.
r(k) = R · cos(α·k), cos α = r_top ⁄ R, k = 0…1 over the upper ⅔
A column is narrower at the top than at the bottom, but the taller the column the less it should be diminished, because distance already makes its top look smaller.
upper Ø : lower Ø = 5⁄6 (≤15 ft) · 11⁄13 (15–20 ft) · 6⁄7 (20–30 ft) · 13⁄15 (30–40 ft) · 7⁄8 (40–50 ft)
Shafts may also be fluted. The Doric has twenty shallow flutes meeting in sharp edges (arrises); the Ionic, Corinthian and Composite have twenty-four deeper ones separated by flat fillets. Flutes catch the light in thin vertical lines that make the column look taller and more alive. The Tuscan is left plain.
The alphabet of mouldings
Look closely at a classical base, capital or cornice and you will find it is made of a few simple profiles combined in different orders. These are the mouldings, and there are essentially eight of them. The fillet is a small flat band. The torus is a large half-round, the astragal a small one. The scotia is a deep hollow; the ovolo a convex quarter-round and the cavetto a concave one. The two S-shaped mouldings are the cyma recta, hollow below and round above, and the cyma reversa, round below and hollow above.
Build every profile from a small set of elements (fillet, torus, astragal, scotia, ovolo, cavetto, cyma recta and cyma reversa), alternating curved with flat and light with shadow.
Convex mouldings catch the light; concave ones hold shadow. A good profile alternates them, separating each curved member with a crisp fillet, so that from a distance the cornice reads as a clear sequence of light and dark bands. The Attic base is the classic example: two tori separated by a scotia, each edged with a fillet. Its lower torus is larger than the upper, so that the base seems to settle firmly on its plinth.
Character
Vitruvius believed that the orders imitated human bodies (the Doric a man, the Ionic a matron, the Corinthian a young girl) and that each suited a particular kind of god. The Renaissance extended the idea: Serlio recommended the Tuscan for fortresses and prisons, the Doric for churches dedicated to soldier saints, the Corinthian for churches of the Virgin. The hierarchy of the orders from plain to rich, from strong to delicate, became a way for a building to announce what it was for.
Use the orders according to their character: the Doric for strength and gravity, the Ionic for a middle dignity, the Corinthian for delicacy and splendour.
The following chapters take the orders one by one, in the sequence Serlio fixed: from the plainest to the richest.
Cite this page Chris Paton, “The Anatomy of an Order”, The Textbook of Architecture, https://textbookofarchitecture.com/chapter/anatomy-of-an-order. Text, drawings and models licensed under CC BY-NC 4.0.