The metopes should be square, and one of the triglyphs is always placed immediately over each column, having the same central axis, hence the spacing of the columns apart is regulated by the triglyphs and metopes. Examples of various spacings of columns will be given later.
The frieze is bounded above and below by rectilinear projecting bands or fillets; that at the top breaks round or follows the projection of the triglyphs.
The triglyphs are so named because they are channelled vertically with grooves or glyphs, V shaped in section, with intervening spaces or inter-glyphs. The width of the triglyph should be divided into twelve parts—then the half glyphs which are placed at the angles will each be one of these parts, and the remaining two glyphs and three inter-glyphs are each two of them. The glyphs terminate at the base on the fillet band, but at the top are cut off a little below the upper fillet, invariably in a straight line, thus forming a triangular heading with the apex of the triangle sloping backwards and downwards in conformity with the V shaped section of the glyphs.
Under the lower fillet band, and immediately below the triglyph, is a small fillet and six pendant drops of conical form known as guttae.
PLAN OF CORNICE
No. 157. Ionic Entablature.
The architrave is half a diameter high, inclusive of the fillet band, which is roughly a sixth of this height. The small fillet and guttae are together equal in height to the fillet band.
It may be taken as an invariable rule that whatever order is used, the face of the architrave must be in vertical alignment with the upper part of the shaft of the column.