=The Marble Flooring.=--Before leaving the Vestibule, the visitor may be interested to notice the design of the marble flooring. The body of it is white Italian, with bands and geometric patterns of brown Tennessee, and edgings of yellow mosaic. It will be seen at once that the design is harmonious with the lines of the arcade and the ceiling. These are not slavishly mimicked, but are developed, varied, and extended. Sometimes a circle is used to draw together two opposite arches; sometimes a square echoes the pattern of the ceiling; lines of beaming--as they may be called in an easy metaphor--connect opposite piers; and finally the boundaries of the corridor are outlined in a broad border enclosing the whole. It has been said that in hardly any other building in the country has so much pains been taken by the architect to make the lines of his floor designs consistent with those of the architecture and the general decorative scheme. Throughout the Library, wherever marble or mosaic is used for this purpose, the visitor will find this phase of the ornamentation of the building of the highest interest and importance. [Illustration: THE MAIN VESTIBULE.] =The Staircase Hall.=--The floor of the Staircase Hall, into which one passes next, is an excellent example of this point. Besides the marble, the pattern contains a number of modelled and incised brass inlays. The one in the centre is a large rayed disc, or conventional sun, on which are noted the four cardinal points of the compass, which coincide with the direction of the main axes of the Library. The disc thus performs the same service for the building--only more picturesquely and vividly--as an arrow-head cross for a chart or plan. From the sun as a centre proceeds a great circular glory--or “scale pattern,” as it is technically, and more descriptively, called--of alternate red and yellow Italian marble, the former from Verona and the latter from Sienna. Other inlays are arranged in a hollow square, enclosing the sun as a centrepiece. Twelve represent the signs of the zodiac; the others are in the form of rosettes, in two patterns. They are embedded in blocks of dark red, richly mottled, French marble, around which are borders of pure white Italian marble. =The Commemorative Arch.=--On the easterly side of the Staircase Hall, on the way to the Reading Room, the regularity of the arcade is interrupted by a portico of equal height, which does duty as a sort of miniature triumphal arch, commemorating the erection of the Library. The spandrels contain two sculptured figures in marble by the late Olin L. Warner, the sculptor of the bronze doors previously described. Along the frieze are the words LIBRARY OF CONGRESS, inscribed in tall gilt letters. A second inscription, giving the names of those concerned in the erection of the Library, is cut upon the marble tablet which forms part of the parapet above. It is flanked by lictors’ axes and eagles, sculptured in marble, and reads as follows: