Cut a shaft with sixteen shallow flutes or facets, give it a square abacus and a low round base: the “proto-Doric” column of the Middle Kingdom rock tombs at Beni Hasan.
Rules · Spacing · Entablatures · Proportion
Contract the corner bays
To end the frieze with a triglyph at the corner and keep every metope square, move the corner column inward: make the last intercolumniation narrower than the others by the amount the corner triglyph is displaced.
contraction c = e − t⁄2; Parthenon: 4.29 m normal, 3.68 m at the corners (c ≈ 0.61 m)
Classical Greek temples almost all use this solution. The corner is strengthened visually as well as solved geometrically: the thicker, closer corner columns frame the colonnade. Some western Greek temples in Sicily went further with double contraction, narrowing the last two bays by smaller amounts so that the irregularity was spread out and less noticeable.
Because the triglyph over the contracted bay is no longer centred over its intercolumniation, the frieze is not strictly regular either: its triglyphs keep their even rhythm while the columns beneath shift. The eye accepts the compromise because the metopes, the most visible elements, stay equal.
Related rules
Make the corner columns thicker than the rest by a fiftieth of their diameter, because, seen against the open sky, they look thinner than they are.
D corner = D × (1 + 1⁄50); Parthenon: 1.95 m against 1.905 m
A Doric frieze cannot obey all three of its rules at a corner: triglyphs over the column axes, a triglyph turning the corner, and metopes as broad as they are high. One of them must give way.
displacement of the corner triglyph = e − t⁄2 (e = half-depth of the architrave, t = triglyph width)
Let one simple ratio govern the whole: at the Parthenon the lower diameter is to the axial spacing, the width of the stylobate to its length, and the height of the order to the width of the front, all very nearly as 4 is to 9.
D : axial spacing ≈ 1.905 : 4.296 ≈ 4 : 9; stylobate 30.88 : 69.50 ≈ 4 : 9
Divide the height from floor to ceiling into three and a half parts and give two and a half to the opening; make a Doric door five and a half twelfths as wide as it is high (an Ionic one two-fifths), and narrow it slightly at the top.
h = 2½⁄3½ H; Doric w = 5½⁄12 h, Ionic w = h ÷ 2½; top narrowed by ⅓, ¼ or ⅛ of the jamb as h ≤ 16, ≤ 25, ≤ 30 ft
Architecture depends on order (ordinatio), arrangement (dispositio), eurythmy, symmetry, propriety (decor) and economy (distributio).
Cite this page Chris Paton, “Contract the corner bays”, The Textbook of Architecture, https://textbookofarchitecture.com/rule/corner-contraction. Text, drawings and models licensed under CC BY-NC 4.0.