It is also generally con ceded that the individual parts of Greek architecture appear to best advantage when the general form of the building itself is Greek. Indeed, the beautiful flat cur v e s and mouldings of this style are quite at variance with anything else than the low pediment, flat roof, and general propor tions of the old Greek temple buildings.
Inclination of the Roof in Greek and Roman Temples. The very form of roof used on these Greek temples, giving a gable or pediment at each end, enclosing a tympanum which was generally decorated with sculpture, is in its slope, simplicity and proportions characteristic of their architectural practice. The inclination of these roofs is very slight. In the Temple of the Erechtheum it is fifteen and one-half degrees; in the Temple of Theseus (Fig. 51) it is fifteen degrees; in the Parthenon (Fig. 45), it is sixteen degrees; while the pediment of the Propylæa (Fig. 88) has an inclination of - fourteen and one-half degrees. It may be interesting to mention, in this connection, that in Roman examples this inclination is steeper. Thus, in the pediment of Septimus Severus it is twenty-two degrees; in the Temple of Concord and Mars Ultor, twenty-three and one-half degrees; and in the Temple of Fortuna Virilis, and Antoninus and Faustina, twenty-four degrees.
The Value of the " Order." The "Order" may be used as the most tangible means of getting at the essential parts of the Greek style, and a study of its forms cannot fail to help towards the appre ciation of the beauty of Greek architecture as a whole.
It is also necessary to realize that the Order is not the most impor tant part of the study of Greek architecture. The Greek building, in all its beauty of proportion, existed long before the Order was devel oped to the point where we study it to-day. The form of roof used on the Greek temples performs, as we have already seen, a much more important part in producing their general effect; and a thorough knowledge of these forms accustoms the eye to refinements which might otherwise not be apprehended. Especially is this so of the
ancient Greek structures.
The Orders, as we have them to-day, are derived from the meas urements of existing remains of Classic Greek and Roman mon uments. Aside from purposes of actual reproduction and their whole or partial use on modern buildings, they are most valuable as ideal types from which the proportions of old and new work may be studied and estimated.
Modern practice and theory do not give to the Orders the impor tance which they have heretofore generally received. Yet these forms have come down to us with more authority than any other single units employed in architectural practice. To comprehend thoroughly the Orders, their purposes and adaptability to modern work, it is important to know the conditions under which they were first developed, so that we must study their use in old and Classic work—where they were a much more important factor in the direct evolution of architecture than now in our climate, and under the social conditions of to-day. It is therefore necessary that the derivation and historical growth of the Orders should be understood, and their use should not be attempted until their forms and proportions have been thoroughly studied. Then, when intelligently used, they may indeed become a vital and consistent part of our modern architecture and life.
' In reproducing any of the Greek Orders the old examples should be followed as closely as possible, as their proportions have been so well defined by time and precedent that at this day these forms should be considered as definite. This stricture is emphasized by the fact that, since the Roman Orders were defined, the Greek style of ar chitecture has been but little used, and no further developed; and in the few instances where it has been revived it was apparently rec ognized that any use of the details or parts of Greek architecture should be modeled as exactly as possible on the actual precedents furnished by old Greek work.