+THE ROMAN ORDERS.+ To meet the demands of Roman taste the Etruscan column was retained with its simple entablature; the Doric and Ionic were adopted in a modified form; the Corinthian was developed into a complete and independent order, and the Composite was added to the list. A regular system of proportions for all these five orders was gradually evolved, and the mouldings were profiled with arcs of circles instead of the subtler Greek curves. In the building of many-storied structures the orders were superposed, the more slender over the sturdier, in an orderly and graded succession. The immense extent and number of the Roman buildings, the coarse materials often used, the relative scarcity of highly trained artisans, and above all, the necessity of making a given amount of artistic design serve for the largest possible amount of architecture, combined to direct the designing of detail into uniform channels. Thus in time was established a sort of canon of proportions, which was reduced to rules by Vitruvius, and revived in much more detailed and precise form by Vignola in the sixteenth century. [Illustration: FIG. 42.--ROMAN DORIC ORDER. (THEATRE OF MARCELLUS).] In each of the orders, including the Doric, the column was given a base one half of a diameter in height (the unit of measurement being the diameter of the lower part of the shaft, the _crassitudo_ of Vitruvius). The shaft was made to contract about one-sixth in diameter toward the capital, under which it was terminated by an _astragal_ or collar of small mouldings; at the base it ended in a slight flare and fillet called the _cincture_. The entablature was in all cases given not far from one quarter the height of the whole column. The +Tuscan+ order was a rudimentary or Etruscan Doric with a column seven diameters high and a simple entablature without triglyphs, mutules, or dentils. But few examples of its use are known. The +Doric+ (Fig. 42) retained the triglyphs and metopes, the mutules and guttæ of the Greek; but the column was made eight diameters high, the shaft was smooth or had deep flutings separated by narrow fillets, and was usually provided with a simple moulded base on a square plinth. Mutules were used only over the triglyphs, and were even replaced in some cases by dentils; the corona was made lighter than the Greek, and a cymatium replaced the antefixæ on the lateral cornices. The Ionic underwent fewer changes, and these principally in the smaller mouldings and details of the capital. The column was nine diameters high (Fig. 43). The +Corinthian+ was made into an independent order by the designing of a special base of small _tori_ and _scotiæ_, and by sumptuously carved _modillions_ or brackets enriching the cornice and supporting the corona above a denticulated bed-mould (Fig. 44). Though the first designers of the modillion were probably Greeks, it must, nevertheless, be taken as really a Roman