their spring, but they were forced on Wren against his better judgment: internally the nave gains greatly; externally they are a mistake. One would perhaps have liked also that the screen-wall of the side aisles of the choir and transepts, instead of ending square, should have circled round in one vast majestic sweep, in harmony with the curving dome above, after the fashion of the fine cathedral of Como. The flatness, moreover, of the side-elevations gives but little room for play of light and shade. There are none of the pits of darkness that lurk between the buttresses and transepts of Beverley or Lincoln. Only in the recessed west front and behind the colonnade of the dome the shadows brood. Nature, however, or rather London smoke, has given St. Paul’s a chiaroscuro of its own—not to be washed off, as has been foolishly proposed, by Vandal fire-engines. Where the rain lashes the building, especially its angles and projections, the good Portland stone is white and clean; where sheltered by projecting cornices it is black as Erebus. [Illustration: FLYING-BUTTRESSES AND SCREEN-WALL.] Externally, it is a building of two stories. Wren designed it originally for one story, but was unable to get big enough blocks of stone to carry a single gigantic Order, as at St. Peter’s, up to the cornice; for which we may be thankful. The façade also is composed of two Orders of columns, and they are necessarily comparatively small columns. But all appearance of weakness is admirably removed by arranging them in couples; indeed, one would be sorry to have instead of this noble design Wren’s own one-story façade as shown in his model,—still more to have that of Inigo Jones. The harmony, too, of the noble design is delightful. The two stories of the columns of the façade become two stories of pilasters on the flanks of the nave; at the ends of the transepts they sweep round into lovely semicircular colonnades; colonnades form the central stages of the western steeples; the drum of the dome is encircled by a superb colonnade; the dome itself culminates in a colonnaded lantern. See, too, how the lantern, domical above and colonnaded below, sums up the composition of the dome beneath; and how the western steeples prepare the eye for the transition from the rectilinear colonnades of the great façade to the swelling curve of the dome,—itself reproduced in the north and south circular porches and in the apsidal choir. St. Paul’s is “a house at one with itself.”