- For other meanings of the term, see column (disambiguation).
In architecture and structural engineering, a column is that part of a structure whose purpose is to transmit through compression the weight of the structure. Other compression member s are often termed columns because of the similar stress conditions. Columns can be either compounded of parts or made as a single piece. Columns are frequently used to support beams or arches on which the upper parts of walls or ceilings rest.
In the architecture of ancient Egypt as early as 2600 BC the architect Imhotep made use of stone columns whose surface was carved to reflect the organic form of bundled reeds; in later Egyptian architecture faceted cylinders were also common.
The classical orders
The Roman author Vitruvius, relying on the writings (now lost) of Greek authors, tells us that the ancient Greeks believed that their Doric order developed from techniques for building in wood in which the earlier smoothed tree trunk was replaced by a stone cylinder. This myth of the transformation of wood into stone still causes controversy today - did the ancient Greeks invent columns this way for themselves, or did they imitate the stone construction of neighboring civilization?
The Doric, or Tuscan, order is the oldest and simplest of the classical order. It is composed of a vertical cylinder that is wider at the bottom. It generally has neither a base nor a capital. It is often referred to as the masculine order because it is represented in the bottom level of the Colosseum, and was therefore considered to be able to hold more weight.
The Ionic column is considerably more complex than the Doric. It usually has a base and the shaft is often fluted (it has grooves carved up its length). On the top is a capital in the characteristic shape of a scroll, called a volute, at the four corners.
The Corinthian order is commonly thought to be named because its legendary origin was in the Greek city-state of Corinth, however the story of its origin is due to Callimachus, a Greek bronze worker drawing a design of acanthus leaves, growing on a small tomb for a new style of capital for the people of Corinth. In fact, the oldest known Corinthian capital was found in Bassae, dated at 427 BC. It is sometimes called the feminine order because it is on the top level of the Colosseum and holding up the least weight. It is similar to the Ionic order, but rather than a scroll, the Corinthian capital consists of rows of acanthus leaves. Many variations have been made on the Corinthian capital. For instance, the capitals of the Capitol building in Washington, DC is made up partially of wheat stalks.