What is an echinus?
The echinus is the round, cushion-shaped element of a classical capital that sits as a curved transition between the shaft of a column and the abacus (top slab). Its form resembles the inverted half-shell of a sea urchin — echinos in Greek, hence the name. The echinus is central to the Doric and Ionic column orders.
Form and function
The echinus serves both structurally and aesthetically:
- Load spreading — gradually broadens the bearing surface from shaft to abacus
- Visual transition — marks the step from the vertical of the shaft to the horizontal of the architrave
- Decoration — gives each order its own character
Variations by order
| Order | Shape of the echinus | Decoration |
|---|---|---|
| Doric | Flat, wide cushion with a sharp profile | Plain, undecorated or with egg-and-dart |
| Ionic | Narrower, flanked by spiral volutes | With egg-and-dart (cymatium) |
| Corinthian | Small, hidden behind acanthus leaves | Dominated by acanthus carving |
| Tuscan | Simple and heavy | No decoration |
Application and history
The echinus is recognisable in:
- Greek temples — Parthenon (Athens), Temple of Aphaia (Aegina)
- Roman architecture — often more elaborately decorated than Greek examples
- Renaissance and Neoclassicism — rediscovery of the classical form
- 19th-century civic architecture — banks, theatres, parliaments
Subtleties
Classical architects paid close attention to the curvature of the echinus:
- Entasis — slight bulge for optical balance
- Apophyge — gentle transition between shaft and echinus
- Annulets — rings beneath the Doric echinus
- Astragal — ornamental ring just below the echinus
Related terms
- Capital
- Abacus
- Column shaft
- Annulets
- Astragal
- Egg-and-dart moulding
- Doric order
- Ionic order
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