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.”
It is true that the dead wall from aisle windows to cornice is perhaps the “most unmitigated building sham upon the face of the earth.” It has absolutely nothing to do at all except to hide away some flying-buttresses—the very ugliest eye ever saw—which Sir Christopher might well be reluctant to expose to the jeers of the man in the street. It is true, too, that there is built up in this dead wall enough good stone to construct half a dozen parish churches. It has been urged that it was built to weight the foot of each flying-buttress after the manner of a Gothic pinnacle. But not even a Gothic baby would have provided continuous abutment for intermittent thrusts. The dead wall may perhaps be defended on artistic, but certainly not on constructional grounds.
INNER DOME, CONE, AND OUTER DOME.
In the dome, Wren had three conflicting ideals to realise: (1) to make the dome so lofty that it should be visible externally from base to summit; (2) to make it so low internally that it should range with the vaulting of nave, choir, and transepts; (3) to finish it with a stone lantern as lofty and heavy as an ordinary church spire. At St. Peter’s the dome externally squats down so low that from most directions one must walk a mile away to get a complete view of it; the internal dome is so lofty as to be invisible from most parts of the church; the lantern is much smaller and lighter than is required by so mighty a dome; and is in a condition of very unstable equilibrium, badly supported, cracked, and tied together in all directions. All these difficulties Wren triumphantly disposed of; nevertheless, for his triumph he has received little but censure and abuse. He made two domes; and brought the inner dome, which is of brick (see diagram), far lower than the outer one—though not low enough. Secondly, he mounted the outer dome, which is of wood covered with lead, on a lofty colonnaded drum, visible of all men even from the narrow street below. Thirdly, between the two domes (see diagram) he built a cone of brick, and on this cone he poised the lantern—which is as heavy as an ordinary church-spire—in perfect security. If the outer dome were removed—e.g., if it were burnt, as it may some day, being of wood—the lantern would still stand perfectly safe on its conical support. In the dome of St. Paul’s Wren’s engineering capacities culminate. But it is more than a piece of engineering. No tower, no spire, no group of towers or spires, impresses itself on the imagination like the dome of St. Paul’s. Lincoln and Salisbury, Lichfield and Durham, retire before the claims of this overwhelming younger pile,
“whose sky-like dome
Hath typified by reach of daring art