1584
THEORY AND PRACTICE OF ENGINEERING.
Book II.
columns 11' parts out of the whole number, 36, into which the parallelogram may be sup-posed to be divided.
The third temple is not sufficiently measured to enable us to examine into its propor-tions ; the total width is 79 feet, of which the united diameters of the six columns occupy36 feet, and the five intercolumniations 43 feet.
The fourth temple is in width 84 feet 9 inches, and in height 56 feet 6 inches or a squareand a half.
The height of the columns beingehtablaturepediment
In all the height is
The height of half the pediment isthe level entablature
Making a height equal to half that of the columns, viz.
Feet.- 34
In.
0
-
- 11
6
-
- 11
0
-
- 56
6
Ft. In.5 6
-
-
-
11 6
columns,
viz.
-
17 0
Thus the heights are in just proportion, one-third being given to the entablature andpediment, and the other two-thirds to the columns and their intermediate spaces, whichare in the proportions of 44 feet 9 inches for the columns, and 40 feet for the five inter-columniations.
The fifth temple is 81 feet in front, the six columns occupying 37 feet 8 inches, and the fiveintercolumniations 43 feet 4 inches. The height of the column is 31 feet, and the entabla-ture 15 feet 6 inches, or one-half the height of the column, so that, without the pediment,the entablature in this example would constitute a third ; and if the pediment had only risen7 feet 6 inches, to make the general proportion a square and a half, these columns wouldhave had more to sustain than any other example we have yet referred to.
Octastyle Temples .— We will now apply these principles to a fa 9 ade with eight columns,and endeavour to follow the same system. We have already had a square, and a squareand a hal£ as the form or figure within which the design was comprised; the portico offour columns being circumscribed by the one, and that of six by the other ; and as in theoctastyle there are double the number of columns contained in the first, a double square isrequired to comprise it, that the same relative proportions may be obtained.
Fig. 2971.
OCTASTYLE PORTICOES,
After the width of the fa 9 ade is determined, it is divided into sixteen parts, and ten are setout for the height to the top of the tympanum of the pediment ; which generally rising aninth of the extent, two divisions will serve to denote it, and if a circle be inscribed in thetympanum, and a horizontal line drawn through the centre, we shall have a parallelogram16 squares in width, and 9 in height.
Six squares in height will determine the under side of the entablature, which, if divided,equally between the columns and their intercolumniations, would give 48 squares to each,which are precisely the proportions of the example we are about to examine.