As the shaft nears the capital, it is encircled by a narrow groove or _annula_. At the top of the shaft is a series of annulæ, some of which are cut in the shaft and others in the lower member of the capital, the _echinus_, so that the shaft appears to project in a necking, into which the capital is set. The _echinus_ is a circular cushion with an eccentric curve; a curve, that is to say, that is not part of a circle. (Compare by contrast the semi-circular curve of the _torus_.) Upon the echinus sets firmly the _abacus_, a square block with a side measurement the same as the diameter of the echinus. The height of the column varied in its proportion to the lower diameter. In the =Temple of Poseidon=, at =Pæstum=, the height is four times the diameter; in the later example of the =Parthenon= nearly five and a half times, while in the =Temple of Jupiter Nemæus= it is six and a half times. The _intercolumniation_, or space between the columns, also varies. In the older temples it was about one diameter of the column, the space between the angle columns being always less; while in the case of the Parthenon the distance varies from one diameter to 1.24; this being an instance of deviation from geometrical regularity to be referred to later. It remains to mention the _antæ_. These were flat, right-angled columns, projecting slightly from the wall of the pronaos at the corners, facing the end columns. While they correspond to the latter, they differ in three respects. The shaft did not taper and was set on a small base, while the capital was distinguished by different mouldings. For the mouldings suitable to a free-standing column, supporting actual weight were felt to be unsuited for a member attached to a wall, whose functions were decorative. =Doric Entablature.=--The principal members of the entablature are the _architrave_ or supporting member, the _frieze_ or decorative member, and the _cornice_ or protecting member. The _architrave_, as its name implies, “the chief beam” of the entablature, rests immediately upon the abacus; its edge corresponding neither with that of the abacus nor with the top edge of the shaft, but so adjusted to both as to ensure a feeling of complete stability. The architrave was usually plain[1] and crowned with a projecting fillet, called the _tænia_, which beneath the _triglyphs_, is supplemented by a lower fillet, known as the _regula_. On the under side of the latter were six studs, which recall perhaps the wooden pegs with which the ends of the beams in primitive construction were fastened.