Читать книгу The Stones of Venice - John Ruskin - Страница 8

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§ I. Our first business, then, is with Wall, and to find out wherein lies the true excellence of the “Wittiest Partition.” For it is rather strange that, often as we speak of a “dead” wall, and that with considerable disgust, we have not often, since Snout’s time, heard of a living one. But the common epithet of opprobrium is justly bestowed, and marks a right feeling. A wall has no business to be dead. It ought to have members in its make, and purposes in its existence, like an organized creature, and to answer its ends in a living and energetic way; and it is only when we do not choose to put any strength nor organization into it, that it offends us by its deadness. Every wall ought to be a “sweet and lovely wall.” I do not care about its having ears; but, for instruction and exhortation, I would often have it to “hold up its fingers.” What its necessary members and excellences are, it is our present business to discover.

§ II. A wall has been defined to be an even and united fence of wood, earth, stone, or metal. Metal fences, however, seldom, if ever, take the form of walls, but of railings; and, like all other metal constructions, must be left out of our present investigation; as may be also walls composed merely of light planks or laths for purposes of partition or inclosure. Substantial walls, whether of wood or earth (I use the word earth as including clay, baked or unbaked, and stone), have, in their perfect form, three distinct members;—the Foundation, Body or Veil, and Cornice.

§ III. The foundation is to the wall what the paw is to an animal. It is a long foot, wider than the wall, on which the wall is to stand, and which keeps it from settling into the ground. It is most necessary that this great element of security should be visible to the eye, and therefore made a part of the structure above ground. Sometimes, indeed, it becomes incorporated with the entire foundation of the building, a vast table on which walls or piers are alike set: but even then, the eye, taught by the reason, requires some additional preparation or foot for the wall, and the building is felt to be imperfect without it. This foundation we shall call the Base of the wall.

§ IV. The body of the wall is of course the principal mass of it, formed of mud or clay, of bricks or stones, of logs or hewn timber; the condition of structure being, that it is of equal thickness everywhere, below and above. It may be half a foot thick, or six feet thick, or fifty feet thick; but if of equal thickness everywhere, it is still a wall proper: if to its fifty feet of proper thickness there be added so much as an inch of thickness in particular parts, that added thickness is to be considered as some form of buttress or pier, or other appliance.33

In perfect architecture, however, the walls are generally kept of moderate thickness, and strengthened by piers or buttresses; and the part of the wall between these, being generally intended only to secure privacy, or keep out the slighter forces of weather, may be properly called a Wall Veil. I shall always use this word “Veil” to signify the even portion of a wall, it being more expressive than the term Body.

§ V. When the materials with which this veil is built are very loose, or of shapes which do not fit well together, it sometimes becomes necessary, or at least adds to security, to introduce courses of more solid material. Thus, bricks alternate with rolled pebbles in the old walls of Verona, and hewn stones with brick in its Lombard churches. A banded structure, almost a stratification of the wall, is thus produced; and the courses of more solid material are sometimes decorated with carving. Even when the wall is not thus banded through its whole height, it frequently becomes expedient to lay a course of stone, or at least of more carefully chosen materials, at regular heights; and such belts or bands we may call String courses. These are a kind of epochs in the wall’s existence; something like periods of rest and reflection in human life, before entering on a new career. Or else, in the building, they correspond to the divisions of its stories within, express its internal structure, and mark off some portion of the ends of its existence already attained.

§ VI. Finally, on the top of the wall some protection from the weather is necessary, or some preparation for the reception of superincumbent weight, called a coping, or Cornice. I shall use the word Cornice for both; for, in fact, a coping is a roof to the wall itself, and is carried by a small cornice as the roof of the building by a large one. In either case, the cornice, small or large, is the termination of the wall’s existence, the accomplishment of its work. When it is meant to carry some superincumbent weight, the cornice may be considered as its hand, opened to carry something above its head; as the base was considered its foot: and the three parts should grow out of each other and form one whole, like the root, stalk, and bell of a flower.

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.

33 Many walls are slightly sloped or curved towards their tops, and have buttresses added to them (that of the Queen’s Bench Prison is a curious instance of the vertical buttress and inclined wall); but in all such instances the slope of the wall is properly to be considered a condition of incorporated buttress.