1590

THEORY AND PRACTICE OF ENGINEERING.

Book II.

Fig. 2982.

IONIC HEXASTYLE TEMPLES.

supposing the tympanum to rise a ninth of its base ; the height of the columns is 21 feet•7^ inches, and their united mean diameter 12 feet 9 inches, which being multiplied togetherproduce 275 feet 8 inches, or nearly equivalent to the area of the mass they support. Toobtain the exact quantity of mass and void, the mean diameters of the columns as wellas of the intercolumniations should be taken; the greater the probable delicacy of ex-ecution, the greater is the necessity for the architect to balance his quantities exactly. Inthe subject now under consideration the whole is comprised within a square and a half; thesupports and the entablature are equal, and the intercolumniations as much as the two to-gether or one-half the whole. The height of the architrave is 2 feet 1 T ^ inches; thatof the frieze 1 foot 1If inches, and the level part of the cornice 10 T ^| inches.

Roman Tetrastyle. Ionic Temple of Fortuna Virilis. —The width is 33 feet 6 inches, andheight, including half the pediment, 37 feet 1 inch, comprising an area of 1242 feet 4 inches,one quarter of which, 313 feet 1 inch, nearly agrees with the quantity contained in theentablature as well as in the columns which support it; their height is 27 feet, and theirunited diameters 12 feet 4 inches, which multiplied together produce 333 feet for the area ofthe supports. The height of the entablature with half the pediment is 10 feet 1 inch : thismultiplied by its width, 33 feet 6 inches, gives 337 feet 10 inches for the area of that supported':the intercolumniations are together 21 feet 2 inches, which multiplied by their height, 27 feet,gives 571 feet 6 inches for their area, about 100 feet less than the quantity comprised inthe columns and entablature.

Without the pediment this fa 9 ade is nearly square; its proportions rank very high inthe estimation of all admirers of Roman architecture; it has, however, undergone many re-parations before the stucco was put upon the columns; they were lighter, as was the entab-lature, the upper members of the cornice being somewhat heavier than is usual in theearly examples of this order ; if divested of these additions, and giving a trifle more to theintercolumniations, we shall obtain half the area for the columns, and a quarter for each ofthe other divisions; at present the columns equal in quantity the mass they carry.

If it be required to draw a tetrastyle portico in exact accordance with the rules laiddown, after forming the square each side should be divided into 12 parts, or 144 squares,arranged like those of an abacus : one of these divisions on the base would become the dia-meter of the column, and nine their height, the other eight on the base would be devoted tothe intercolumniations, and the upper three of the height to the entablature. The columns, 9diameters in height, would thus comprise 36 squares, the intercolumniations 72, and theentablature and half pediment 36; consequently the columns and entablature would beequal in quantity, and the intercolumniations half the whole, or equal to the contents ofthe supports and supported.

Roman Hexastyle . Corinthian , Maison Carree at Nismes . — This beautiful temple hasundergone several restorations; its entire width and height to the apex of the pediment is43 feet 8 inches, from whence it has derived its name. The height of the columns, includ-