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which the small steps on the stylobata produce, which
must be added to them on the central part of the top of
the abacus, that the regularity of the epistylia may be
preserved : we may now consider the proportion of these
epistylia, or architraves. When the columns are at least
twelve and not more than fifteen feet high, the architrave
must be half a diameter in height. When they are from
fifteen to twenty feet in height, the height of the column
is to be divided into thirteen parts, and one of them
taken for the height of the architrave. So from twenty
to twenty-five feet, let the height be divided into twelve
parts and a half, and one part be taken for the height of
the architrave. Thus, in proportion to the height of the
column, is the architrave to be proportioned; always
remembering, that the higher the eye has to reach, the
greater is the difficulty it has in piercing the density of
the air, its power being diminished as the height in-
creases ; of which the result is, a confusion of the imagé.
Hence, to preserve a sensible proportion of parts, if in
high situations, or of colossal dimensions, we must
modify them accordingly, so that they may appear of the
size intended. The under side of the architrave is to
be as wide as the upper diameter of the column, at the
part under the capital ; its upper part equal in width to
the lower diameter of the column. Its cymatium is to
be one-seventh part of the whole height, and its projec-
tion the same. After the cymatium is taken out, the
remainder is to be divided into twelve parts, three of
which are to be given to the lower fascia, four to the
next, and five to the upper one. The zophorus, or
frieze, is placed over the epistylium, than which it must
be one fourth less in height; but if sculptured, it must
be one fourth part higher, that the effect of the carving
may not be injured. Its cymatium is to be a seventh
part of its height, the projection equal to the height.
Above the frieze is placed the dentil-band, whose height
must be equal to that of the middle fascia of the archi¬