These three parts we shall examine in succession; and, first, the Base.
§ VII. It may be sometimes in our power, and it is always expedient, to prepare for the whole building some settled foundation, level and firm, out of sight. But this has not been done in some of the noblest buildings in existence. It cannot always be done perfectly, except at enormous expense; and, in reasoning upon the superstructure, we shall never suppose it to be done. The mind of the spectator does not conceive it; and he estimates the merits of the edifice on the supposition of its being built upon the ground. Even if there be a vast table land of foundation elevated for the whole of it, accessible by steps all round, as at Pisa, the surface of this table is always conceived as capable of yielding somewhat to superincumbent weight, and generally is so; and we shall base all our arguments on the widest possible supposition, that is to say, that the building stands on a surface either of earth, or, at all events, capable of yielding in some degree to its weight.
Fig. II.
§ VIII. Now, let the reader simply ask himself how, on such a surface, he would set about building a substantial wall, that should be able to bear weight and to stand for ages. He would assuredly look about for the largest stones he had at his disposal, and, rudely levelling the ground, he would lay these well together over a considerably larger width than he required the wall to be (suppose as at a, Fig. II.), in order to equalise the pressure of the wall over a large surface, and form its foot. On the top of these he would perhaps lay a second tier of large stones, b, or even the third, c, making the breadth somewhat less each time, so as to prepare for the pressure of the wall on the centre, and, naturally or necessarily, using somewhat smaller stones above than below (since we supposed him to look about for the largest first), and cutting them more neatly. His third tier, if not his second, will probably appear a sufficiently secure foundation for finer work; for if the earth yield at all, it will probably yield pretty equally under the great mass of masonry now knit together over it. So he will prepare for the wall itself at once by sloping off the next tier of stones to the right diameter, as at d. If there be any joints in this tier within the wall, he may perhaps, for further security, lay a binding stone across them, e, and then begin the work of the wall veil itself, whether in bricks or stones.
§ IX. I have supposed the preparation here to be for a large wall, because such a preparation will give us the best general type. But it is evident that the essential features of the arrangement are only two, that is to say, one tier of massy work for foundation, suppose c, missing the first two; and the receding tier or real foot of the wall, d. The reader will find these members, though only of brick, in most of the considerable and independent walls in the suburbs of London.
§ X. It is evident, however, that the general type, Fig. II., will be subject to many different modifications in different circumstances. Sometimes the ledges of the tiers a and b may be of greater width; and when the building is in a secure place, and of finished masonry, these may be sloped off also like the main foot d. In Venetian buildings these lower ledges are exposed to the sea, and therefore left rough hewn; but in fine work and in important positions the lower ledges may be bevelled and decorated like the upper, or another added above d; and all these parts may be in different proportions, according to the disposition of the building above them. But we have nothing to do with any of these variations at present, they being all more or less dependent upon decorative considerations, except only one of very great importance, that is to say, the widening of the lower ledge into a stone seat, which may be often done in buildings of great size with most beautiful effect: it looks kind and hospitable, and preserves the work above from violence. In St. Mark’s at Venice, which is a small and low church, and needing no great foundation for the wall veils of it, we find only the three members, b, c, and d. Of these the first rises about a foot above the pavement of St. Mark’s Place, and forms an elevated dais in some of the recesses of the porches, chequered red and white; c forms a seat which follows the line of the walls, while its basic character is marked by its also carrying certain shafts with which we have here no concern; d is of white marble; and all are enriched and decorated in the simplest and most perfect manner possible, as we shall see in Chap. XXV. And thus much may serve to fix the type of wall bases, a type oftener followed in real practice than any other we shall hereafter be enabled to determine: for wall bases of necessity must be solidly built, and the architect is therefore driven into the adoption of the right form; or if he deviate from it, it is generally in meeting some necessity of peculiar circumstances, as in obtaining cellars and underground room, or in preparing for some grand features or particular parts of the wall, or in some mistaken idea of decoration,—into which errors we had better not pursue him until we understand something more of the rest of the building: let us therefore proceed to consider the wall veil.
CHAPTER V.
THE WALL VEIL
§ I. The summer of the year 1849 was spent by the writer in researches little bearing upon his present subject, and connected chiefly with proposed illustrations of the mountain forms in the works of J. M. W. Turner. But there are sometimes more valuable lessons to be learned in the school of nature than in that of Vitruvius, and a fragment of building among the Alps is singularly illustrative of the chief feature which I have at present to develope as necessary to the perfection of the wall veil.
It is a fragment of some size; a group of broken walls, one of them overhanging; crowned with a cornice, nodding some hundred and fifty feet over its massy flank, three thousand above its glacier base, and fourteen thousand above the sea,—a wall truly of some majesty, at once the most precipitous and the strongest mass in the whole chain of the Alps, the Mont Cervin.
§ II. It has been falsely represented as a peak or tower. It is a vast ridged promontory, connected at its western root with the Dent d’Erin, and lifting itself like a rearing horse with its face to the east. All the way along the flank of it, for half a day’s journey on the Zmutt glacier, the grim black terraces of its foundations range almost without a break; and the clouds, when their day’s work is done, and they are weary, lay themselves down on those foundation steps, and rest till dawn, each with his leagues of grey mantle stretched along the grisly ledge, and the cornice of the mighty wall gleaming in the moonlight, three thousand feet above.
§ III. The eastern face of the promontory is hewn down, as if by the single sweep of a sword, from the crest of it to the base; hewn concave and smooth, like the hollow of a wave: on each flank of it there is set a buttress, both of about equal height, their heads sloped out from the main wall about seven hundred feet below its summit. That on the north is the most important; it is as sharp as the frontal angle of a bastion, and sloped sheer away to the north-east, throwing out spur beyond spur, until it terminates in a long low curve of russet precipice, at whose foot a great bay of the glacier of the Col de Cervin lies as level as a lake. This spur is one of the few points from which the mass of the Mont Cervin is in anywise approachable. It is a continuation of the masonry of the mountain itself, and affords us the means of examining the character of its materials.
§ IV. Few architects would like to build with them. The slope of the rocks to the north-west is covered two feet deep with their ruins, a mass of loose and slaty shale, of a dull brick-red color, which yields beneath the foot like ashes, so that, in running down, you step one yard, and slide three. The rock is indeed hard beneath, but still disposed in thin courses of these cloven shales, so finely laid that they look in places more like a heap of crushed autumn leaves than a rock; and the first sensation is one of unmitigated surprise, as if the mountain were upheld by miracle; but surprise becomes more intelligent reverence for the great builder, when we find, in the middle of the mass of these dead