For effect, the Persian architecture must have depended, firstly, upon the harmony that is produced by the observance of regularity and proportion; and, secondly, upon two main features of the style. These were the grand sculptured staircases which formed the approaches to all the principal buildings, and the vast groves of elegant pillars in and about the great halls. The lesser buildings were probably ugly, except in front. But such edifices as the Chehl Minar at Persepolis, and its duplicate at Susa--where long vistas of columns met the eye on every side, and the great central cluster was supported by lighter detached groups, combining similarity of form with some variety of ornament, where richly colored drapings contrasted with the cool gray stone of the building, and a golden roof overhung a pavement of many hues--must have been handsome, from whatever side they were contemplated, and for general richness and harmony of effect may have compared favorably with any edifices which, up to the time of their construction, had been erected in any country or by any people. If it may seem to some that they were wanting in grandeur, on account of their comparatively low height--a height which, including that of the platform, was probably in no case much more than a hundred feet--it must be remembered that the buildings of Greece and (except the Pyramids) those of Egypt, had the same defect, and that, until the constructive powers of the arch came to be understood, it was almost impossible to erect a building that should be at once lofty and elegant. Height, moreover, if the buildings are for use, implies inconvenience, a waste of time and power being involved in the ascent and descent of steps. The ancient architects, studying utility more than effect, preferred spreading out their buildings to piling them up, and rarely, unless in thickly-peopled towns, even introduced a second story. The spectator, however, was impressed with a sense of grandeur in another way. The use of huge blocks of stone, not only in platforms, but in the buildings themselves, in the shafts of pillars, the antae of porticos, the jambs of doorways, occasionally in roofs, and perhaps in epistylia, produced the same impression of power, and the same feeling of personal insignificance in the beholder, which is commonly effected by great size in the edifice, and particularly by height. The mechanical skill required to transport and raise into place the largest of these blocks must have been very considerable, and their employment causes not merely a blind admiration of those who so built on the part of ignorant persons, but a profound respect for them on the part of those who are by their studies and tastes best qualified for pronouncing on the relative and absolute merits of architectural masterpieces.