At S. Sophia the four main varieties of the new capital are all found. In the cistern the change of form is made by rounding away the angles at the bottom without reference apparently to any geometrical idea; but in other capitals which belong essentially to this type the method seems to have been that explained in Fig. 53 which represents the form of the caps of the lamp pillars on the front of the western gynaeceum. They are most delicately carved with a network of ornament, but the general form is undisturbed as we have explained. The plain capitals of the west window and the isolated sculptured capital Salzenberg found in the north aisle are also of this form, which we shall call the Impost Capital type I. The profile can be made convex or inflected, we are only speaking of the simplest method of changing the form from a circle to a square. [Illustration: FIG. 52.--Columns in Gallery.] Two capitals now used as mounting blocks outside the east porch, which we illustrate (Fig. 51), furnish us with a sculptured example of a similar capital in two stages of development, one of them never having been completed. We give here an outline of the blocked out capital, in which the method of workmanship may be plainly seen. First, the block was cut away below convexly to meet the circular shaft. In this state it exactly resembles the capitals of the cistern. Secondly, on this was marked a border all round the top; also centre lines running down each of the faces, about the centre point of each of which a circle of about seven inches diameter was drawn; and at the bottom the width for the necking was marked off. Thirdly, the intermediate spaces were sunk about two inches; the hollow of the abacus was formed; the necking, and edge of the circular discs were rounded. This brings the capital to the stage shown in the diagram, the point to be observed being that the abacus, boss, and necking lie in one surface, first obtained, and the rest in another face, sunk some two inches below the former. It cannot be doubted that the style of these capitals is contemporary with the work at S. Sophia, and the finished one bears a monogram which appears to read ΘΕΟΔΩΡΟΥ; it is, however, almost identical with that of Theodora, which occurs on the capitals of the interior. MM. Curtis and Aristarches,[358] who have written on these monograms, think it belonged to a portico, restored in 409 by an eparch called Theodoros. Work of this style was not done at that time, and these capitals possibly belonged to some of the outer courts of the church mentioned by Procopius. They resemble the great capitals so closely that they might almost be preliminary studies. The strips which are left down two sides of the capitals were customary in the capitals of a Byzantine colonnade, especially where screens were inserted between. [Illustration: FIG. 53.--Rudimentary Form of Capital. Type I.] [Illustration: FIG. 54.--Rudimentary Form of Capital. Type II.]