The special features, however, for artistic study in Grecian architecture, of whatever order, are the exquisiteness of its proportions, the purity of its lines, the refinement of its mouldings and enrichments, and the superhuman instinct it evinces for delicacy and almost spirituality in the refinement and perfection of every line; but above all these is the manner in which it welcomes, indeed presses, into its service--or rather devotes itself to the service of--the all-glorious sculpture of which it was at once the dutiful handmaid and the loving mistress. Nor need we doubt that it treated the painter’s art one whit less lovingly. As a style, the sentiment of Greek architecture may be said to be a quiet, calm solidity and repose, free from all question as to its stability, because it admits of no pressure but what is vertical. This quality, however, it shares with the Egyptian; but the Greek unites with it the most studied symmetry of proportion, the greatest purity of line, the most refined detail, and the noblest allied art. When the Greek orders were adopted by the Romans--a most natural alliance, seeing that the Greeks built within a comparatively short distance from Rome on the south, and that the Etruscans in the north borrowed Greek decorative art--we find that they united with it an element in itself discordant with the simple static principle which gave such calm dignity to the Greek. It is, as I have heard, a saying among the Moslem builders in India that the arch “never sleeps;” it is always night and day pushing outward. Thus, purely trabeated architecture sleeps in safety, while arcuated architecture never ceases to exert force. The one is a static, the other a dynamic style--only becoming static when its abutments are of undoubted sufficiency. Thus, repose belongs of a right to one, but has to be purposely secured in the other. We know next to nothing of the early architecture of the Romans. Recent excavations show the walls of the time of the kings to have been pretty much like those of Etruscan cities; and it is probable that, like the Etruscans, they early introduced the arch as a leading principle of construction. When they superadded to their own architecture (whatever it was) that of Greece, the latter became in many cases an artistic veil, concealing more or less the actual construction; and even where the artistic effect was purely trabeated, we find arches used behind it to aid the apparent construction. The two systems were thus used together and side by side, gradually uniting themselves into one. In purely engineering works the arch became boldly predominant. In purely architectural works it was often wholly concealed; while in works of an intermediate kind the two were used together, naturally and with perfect freedom. Nor were these or the purely arcuated structures open to the objection of presenting any apparent instability, for their massiveness was such as to defy all suspicion of want of strength.