As the jambs of the doorways were generally built on an angle, the contiguous shafts and arches sometimes gave the effect of an arched passage in perspective. Such effects were frequently intentional in the churches in Southern France, for we find that the walls of the nave and vault of Notre Dame de Poitiers, and of other buildings, were purposely made to converge in order to give the appearance of greater length. It was not uncommon to give the doors square heads, supported by corbels and occasionally by a central shaft; in these cases the arch above relieved the lintel from the weight of the superstructure, and gave the character of the style to the whole. The tympanum, thus enclosed, offered a ground for rich sculpture, which was availed of to the fullest extent. The outer door of a porch was usually richer in design than the inner one; in England there are many examples of shallow porches with single deeply recessed doors. In Provence there are many beautiful examples, foremost amongst which must be mentioned the porch of St. Trophyme, at Arles (see frontispiece). Romanesque windows were but modifications of the doors; often having recessed shafts at their sides and being frequently divided by a central column. The bull’s-eye, or round window, of the early Christian basilicas continued to be used, but it had not as yet the richness of tracery which it attained in the Gothic period. Classical features of design still retained their hold upon many details, notably in the cornices, where the modillions or brackets of the Corinthian order were frequently employed, and but slightly altered in form, although of native composition. The corona of the cornice also differed but little from the Roman models, and was occasionally supported directly by engaged columns replacing buttresses, chiefly on the exterior of apsidal chapels. In the early Christian churches the apse had consisted of a central semicircular termination to the building, flanked occasionally by two smaller semicircular recesses containing altars. In the baptisteries and Byzantine churches these had been multiplied, and had come to be customary features in every new building. In England, the Norman architects generally ended their churches rectangularly, without even the original single apse, though there are a few examples in which it is used, as at Newhaven, Sussex. In Germany it was frequently the custom to affix apses to three sides of the square tower placed at the intersection of the nave and transept, and the result was generally satisfactory, as may be seen in St. Martin’s of Cologne, and in the Apostles’ Church in the same city. [Illustration: PLAN OF STRASBOURG CATHEDRAL (Compare with Basilica, page 89.)]