COLUMN, in the orders of classic architecture, consists of a conic or colloidal frustum, called the shaft, tapering upwards in the manner of a tree, with an assemblage of parts at the upper extremity, termed the capital, and with sometimes another assemblage of parts at the lower extremity, called the base. The capital finishes with a horizontal table, either square on the plan, or capable of being inscribed in a square, called the abacus. The base, also, when there is one, most frequently stands on a table, square on the plan, and hori zontal on the upper and lower sides, called the plinth.
Vit•uvius directs the columns at the angles to be made thicker than the intermediate ones; the diameter of columns to be proportioned to the intereoluirms; that the higher they are, their diminution should lie less; that those on the flanks and angles have their inner faces toward the walls perpen dicular, but those of the pronaos and postieum to he set perpendicular on their axes; that those in theatres and other works of gaiety, should not have the same proportion as those in sacred edifices; and that the two middle columns, opposite the entry, should have a wider interval than any two of the others.
The Greeks seblotn employed attached columns; the only instances of the kind in Attica, and indeed in all Gree•e, are the monument of Lysierates and the temple of Minerva Polias, \Otero the columns present something more than half their diameter. In the temples Agrigentum and /Eseula pins, in Sicily. the columns are also attached. The remains of Roman edifices show many instances of attached columns, as in the temple of Fortune, the triumphal arch of Titus, the Coliseum, and the theatre of Marcellus, at Rome, where the columns project only half' their diameter ; and this rule was strictly observed by the ancients, who generally tapered the shafts from the base.
The Grecian Doric is without a base, which is peculiar to the Ionic and Corinthian orders. Much has been said con cerning the proportion of columns; but it must chiefly depend upon their situation, whether disposed on the exterior or interior, attached or insulated, on a level with the eye or raised above it ; circumstances which will afrcet the propor tion, and reticler all canonical rules uncertain. We also judge of the proportion of columns from the materials a hereof they are constrneted, as a column of iron will require a different proportion from one of snme.
Some columns have the lower third quite cylindrical, and the upper two-thirds only diminished, but the most beautiful diminish from the bottom.
In the prefave to Stewart's third volume. of Antignities, speaking of the temple of Jupiter Olympus, at Athens, Mr. Revelev, who conducted that V01111110. observes, that the columns diminish from the bottom by a beautiful curve line." In another part of the same preface, he Ihrther observes, generally. that " the column:: rise, with consider able dii ninution. in the most graceful sweeping lutes." It is much to be that "Mr. Stewart, who has, in general, been so particular in the measures of Grecian architecture, sin add have neglected a thing so important as the dimensions of the shafts of columns.
The e(dutons of the Pantheon, of the temples of of Jupiter Stator, of Antoninus and Faustina, of Concord. of the arch of Titus, of the portico of Septhnius, and of the theatre of Mareellus, at Rome, are all diminished from the bottom, Columns may be diminished by a curve, according to any of the following methods: