With regard to the arrangement of the triglyphs, one is placed over every column, and one or more intermediately over every _intercolumn_ (or space between two columns), at such distance from each other that the metopes are square; in other words, the height of the triglyph is the measure for the distance between it and the next one. In the best Greek examples of the Order there is only a single triglyph over each intercolumn, whence that mode is sometimes called _monotriglyphic_ or single-triglyphed intercolumniation; which is the closest of all, the distance from axis to axis of the columns being limited to the space occupied above by two metopes and two triglyphs, _i. e._ one whole triglyph and two halves of triglyphs. In such intercolumniation the number of the triglyphs is double the number of the columns, minus one. Further, it is evident that as there must be a triglyph over every column, the triglyphs must regulate the intercolumniation. The width of the intercolumns cannot be at all less than the proportion above mentioned; neither can it be increased, except by introducing a second triglyph,—and if a second triglyph, a second metope also, over each intercolumn, thus augmenting the distance between the columns to half as much again, which becomes, perhaps, too much, the difference between that and the other mode being considerably more than the diameter of a column; whereas in the other Orders the intercolumns may be made, at pleasure, either a little wider or a little narrower than usual. One peculiarity of the Grecian Doric frieze is, that the end triglyphs, instead of being, like the others, in the same axis or central line as the columns beneath, are placed quite up to the edge or outer angle of the frieze. In itself this is, perhaps, rather a defect than the contrary, although intended to obviate another defect,—that of a half metope or blank space there,—for it produces not only some degree of irregularity, but of æsthetic inconsistency also, the triglyph so placed being, as it were, on one side of, instead of directly over the column. One advantage attending it is, that the extreme intercolumns become in consequence narrower than the others by half a triglyph, and accordingly a greater degree and expression of strength is given to the extremities of a portico.