And gradually, as you let the eye follow the sweep of the vaulting arches, from the small central keystone-boss, with the Lamp carved on it, to the broad capitals of the hexagonal pillars at the angles,—there will form itself in your mind, I think, some impression not only of vastness in the building, but of great daring in the builder; and at last, after closely following out the lines of a fresco or two, and looking up and up again to the coloured vaults, it will become to you literally one of the grandest places you ever entered, roofed without a central pillar. You will begin to wonder that human daring ever achieved anything so magnificent.

But just go out again into the cloister, and recover knowledge of the facts. It is nothing like so large as the blank arch which at home we filled with brickbats or leased for a gin-shop under the last railway we made to carry coals to Newcastle. And if you pace the floor it covers, you will find it is three feet less one way, and thirty feet less the other, than that single square of the Cathedral which was roofed like a tailor's loft,—accurately, for I did measure here, myself, the floor of the Spanish chapel is fifty-seven feet by thirty-two.

I hope, after this experience, that you will need no farther conviction of the first law of noble building, that grandeur depends on proportion and design—not, except in a quite secondary degree, on magnitude. Mere size has, indeed, under all disadvantage, some definite value; and so has mere splendour. Disappointed as you may be, or at least ought to be, at first, by St. Peter's, in the end you will feel its size,—and its brightness. These are all you can feel in it—it is nothing more than the pump-room at Leamington built bigger;—but the bigness tells at last: and Corinthian pillars whose capitals alone are ten feet high, and their acanthus leaves, three feet six long, give you a serious conviction of the infallibility of the Pope, and the fallibility of the wretched Corinthians, who invented the style indeed, but built with capitals no bigger than hand-baskets.

Vastness has thus its value. But the glory of architecture is to be—whatever you wish it to be,—lovely, or grand, or comfortable,—on such terms as it can easily obtain. Grand, by proportion—lovely, by imagination—comfortable, by ingenuity—secure, by honesty: with such materials and in such space as you have got to give it.

Grand—by proportion, I said; but ought to have said by disproportion. Beauty is given by the relation of parts—size, by their comparison. The first secret in getting the impression of size in this chapel is the disproportion between pillar and arch. You take the pillar for granted,—it is thick, strong, and fairly high above your head. You look to the vault springing from it—and it soars away, nobody knows where.

Another great, but more subtle secret is in the inequality and immeasurability of the curved lines; and the hiding of the form by the colour.

To begin, the room, I said, is fifty-seven feet wide, and only thirty-two deep. It is thus nearly one-third larger in the direction across the line of entrance, which gives to every arch, pointed and round, throughout the roof, a different spring from its neighbours.

The vaulting ribs have the simplest of all profiles—that of a chamfered beam. I call it simpler than even that of a square beam; for in barking a log you cheaply get your chamfer, and nobody cares whether the level is alike on each side: but you must take a larger tree, and use much more work to get a square. And it is the same with stone.

And this profile is—fix the conditions of it, therefore, in your mind,—venerable in the history of mankind as the origin of all Gothic tracery-mouldings; venerable in the history of the Christian Church as that of the roof ribs, both of the lower church of Assisi, bearing the scroll of the precepts of St. Francis, and here at Florence, bearing the scroll of the faith of St. Dominic. If you cut it out in paper, and cut the corners off farther and farther, at every cut, you will produce a sharper profile of rib, connected in architectural use with differently treated styles. But the entirely venerable form is the massive one in which the angle of the beam is merely, as it were, secured and completed in stability by removing its too sharp edge.

Well, the vaulting ribs, as in Giotto's vault, then, have here, under their painting, this rude profile: but do not suppose the vaults are simply the shells cast over them. Look how the ornamental borders fall on the capitals! The plaster receives all sorts of indescribably accommodating shapes—the painter contracting and stopping his design upon it as it happens to be convenient. You can't measure anything; you can't exhaust; you can't grasp,—except one simple ruling idea, which a child can grasp, if it is interested and intelligent: namely, that the room has four sides with four tales told upon them; and the roof four quarters, with another four tales told on those. And each history in the sides has its correspondent history in the roof. Generally, in good Italian decoration, the roof represents constant, or essential facts; the walls, consecutive histories arising out of them, or leading up to them. Thus here, the roof represents in front of you, in its main quarter, the Resurrection—the cardinal fact of Christianity; opposite (above, behind you), the Ascension; on your left hand, the descent of the Holy Spirit; on your right, Christ's perpetual presence with His Church, symbolized by His appearance on the Sea of Galilee to the disciples in the storm.