The Stones of Venice, Volume 1 (of 3)

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 leaves, a course of living rock, of quartz as white as the snow that encircles it, and harder than a bed of steel.

§ V. It is one only of a thousand iron bands that knit the strength of the mighty mountain. Through the buttress and the wall alike, the courses of its varied masonry are seen in their successive order, smooth and true as if laid by line and plummet,34 but of thickness and strength continually varying, and with silver cornices glittering along the edge of each, laid by the snowy winds and carved by the sunshine,—stainless ornaments of the eternal temple, by which “neither the hammer nor the axe, nor any tool, was heard while it was in building.”

§ VI. I do not, however, bring this forward as an instance of any universal law of natural building; there are solid as well as coursed masses of precipice, but it is somewhat curious that the most noble cliff in Europe, which this eastern front of the Cervin is, I believe, without dispute, should be to us an example of the utmost possible stability of precipitousness attained with materials of imperfect and variable character; and, what is more, there are very few cliffs which do not display alternations between compact and friable conditions of their material, marked in their contours by bevelled slopes when the bricks are soft, and vertical steps when they are harder. And, although we are not hence to conclude that it is well to introduce courses of bad materials when we can get perfect material, I believe we may conclude with great certainty that it is better and easier to strengthen a wall necessarily of imperfect substance, as of brick, by introducing carefully laid courses of stone, than by adding to its thickness; and the first impression we receive from the unbroken aspect of a wall veil, unless it be of hewn stone throughout, is that it must be both thicker and weaker than it would have been, had it been properly coursed. The decorative reasons for adopting the coursed arrangement, which we shall notice hereafter, are so weighty, that they would alone be almost sufficient to enforce it; and the constructive ones will apply universally, except in the rare cases in which the choice of perfect or imperfect material is entirely open to us, or where the general system of the decoration of the building requires absolute unity in its surface.

Fig. III.

§ VII. As regards the arrangement of the intermediate parts themselves, it is regulated by certain conditions of bonding and fitting the stones or bricks, which the reader need hardly be troubled to consider, and which I wish that bricklayers themselves were always honest enough to observe. But I hardly know whether to note under the head of æsthetic or constructive law, this important principle, that masonry is always bad which appears to have arrested the attention of the architect more than absolute conditions of strength require. Nothing is more contemptible in any work than an appearance of the slightest desire on the part of the builder to direct attention to the way its stones are put together, or of any trouble taken either to show or to conceal it more than was rigidly necessary: it may sometimes, on the one hand, be necessary to conceal it as far as may be, by delicate and close fitting, when the joints would interfere with lines of sculpture or of mouldings; and it may often, on the other hand, be delightful to show it, as it is delightful in places to show the anatomy even of the most delicate human frame: but studiously to conceal it is the error of vulgar painters, who are afraid to show that their figures have bones; and studiously to display it is the error of the base pupils of Michael Angelo, who turned heroes’ limbs into surgeons’ diagrams,—but with less excuse than theirs, for there is less interest in the anatomy displayed. Exhibited masonry is in most cases the expedient of architects who do not know how to fill up blank spaces, and many a building, which would have been decent enough if let alone, has been scrawled over with straight lines, as in Fig. III., on exactly the same principles, and with just the same amount of intelligence as a boy’s in scrawling his copy-book when he cannot write. The device was thought ingenious at one period of architectural history; St. Paul’s and Whitehall are covered with it, and it is in this I imagine that some of our modern architects suppose the great merit of those buildings to consist. There is, however, no excuse for errors in disposition of masonry, for there is but one law upon the subject, and that easily complied with, to avoid all affectation and all unnecessary expense, either in showing or concealing. Every one knows a building is built of separate stones; nobody will ever object to seeing that it is so, but nobody wants to count them. The divisions of a church are much like the divisions of a sermon; they are always right so long as they are necessary to edification, and always wrong when they are thrust upon the attention as divisions only. There may be neatness in carving when there is richness in feasting; but I have heard many a discourse, and seen many a church wall, in which it was all carving and no meat.

CHAPTER VI.

THE WALL CORNICE

§ I. We have lastly to consider the close of the wall’s existence, or its cornice. It was above stated, that a cornice has one of two offices: if the wall have nothing to carry, the cornice is its roof, and defends it from the weather; if there is weight to be carried above the wall, the cornice is its hand, and is expanded to carry the said weight.

There are several ways of roofing or protecting independent walls, according to the means nearest at hand: sometimes the wall has a true roof all to itself; sometimes it terminates in a small gabled ridge, made of bricks set slanting, as constantly in the suburbs of London; or of hewn stone, in stronger work; or in a single sloping face, inclined to the outside. We need not trouble ourselves at present about these small roofings, which are merely the diminutions of large ones; but we must examine the important and constant member of the wall structure, which prepares it either for these small roofs or for weights above, and is its true cornice.

§ II. The reader will, perhaps, as heretofore, be kind enough to think for himself, how, having carried up his wall veil as high as it may be needed, he will set about protecting it from weather, or preparing it for weight. Let him imagine the top of the unfinished wall, as it would be seen from above with all the joints, perhaps uncemented, or imperfectly filled up with cement, open to the sky; and small broken materials filling gaps between large ones, and leaving cavities ready for the rain to soak into, and loosen and dissolve the cement, and split, as it froze, the whole to pieces. I am much mistaken if his first impulse would not be to take a great flat stone and lay it on the top; or rather a series of such, side by side, projecting well over the edge of the wall veil. If, also, he proposed to lay a weight (as, for instance, the end of a beam) on the wall, he would feel at once that the pressure of this beam on, or rather among, the small stones of the wall veil, might very possibly dislodge or disarrange some of them; and the first impulse would be, in this case, also to lay a large flat stone on the top of all to receive the beam, or any other weight, and distribute it equally among the small stones below, as at a, Fig. IV.

Fig. IV.

§ III. We must therefore have our flat stone in either case; and let b, Fig. IV., be the section or side of it, as it is set across the wall. Now, evidently, if by any chance this weight happen to be thrown more on the edges of this stone than the centre, there will be a chance of these edges breaking off. Had we not better, therefore, put another stone, sloped off to the wall, beneath the projecting one, as at c. But now our cornice looks somewhat too heavy for the wall; and as the upper stone is evidently of needless thickness, we will thin it somewhat, and we have the form d. Now observe: the lower or bevelled stone here at d corresponds to d in the base (Fig. II., page 59). That was the foot of the wall; this is its hand. And the top stone here, which is a constant member of cornices, corresponds to the under stone c, in Fig. II., which is a constant member of bases. The reader has no idea at present of the enormous importance of these members; but as we shall have to refer to them perpetually, I must ask him to compare them, and fix their relations well in his mind: and, for convenience, I shall call the bevelled or sloping stone, X, and the upright edged stone, Y. The reader may remember easily which is which; for X is an intersection of two slopes, and may therefore properly mean either of the two sloping stones; and Y is a figure with a perpendicular line and two slopes, and may therefore fitly stand for the upright stone in relation to each of the sloping ones; and as we shall have to say much more about cornices than about bases, let X and Y stand for the stones of the cornice, and Xb and Yb for those of the base, when distinction is needed.

§ IV. Now the form at d, Fig. IV., is the great root and primal type of all cornices whatsoever. In order to see what forms may be developed from it, let us take its profile a little larger—a, Fig. V., with X and Y duly marked. Now this form, being the root of all cornices, may either have to finish the wall and so keep off rain; or, as so often stated, to carry weight. If the former, it is evident that, in its present profile, the rain will run back down the slope of X; and if the latter, that the sharp angle or edge of X, at k, may be a little too weak for its work, and run a chance of giving way. To avoid the evil in the first case, suppose we hollow the slope of X inwards, as at b; and to avoid it in the second case, suppose we strengthen X by letting it bulge outwards, as at c.

Fig. V.

§ V. These (b and c) are the profiles of two vast families of cornices, springing from the same root, which, with a third arising from their combination (owing its origin to æsthetic considerations, and inclining sometimes to the one, sometimes to the other), have been employed, each on its third part of the architecture of the whole world throughout all ages, and must continue to be so employed through such time as is yet to come. We do not at present speak of the third or combined group; but the relation of the two main branches to each other, and to the line of origin, is given at e, Fig. V.; where the dotted lines are the representatives of the two families, and the straight line of the root. The slope of this right line, as well as the nature of the curves, here drawn as segments of circles, we leave undetermined: the slope, as well as the proportion of the depths of X and Y to each other, vary according to the weight to be carried, the strength of the stone, the size of the cornice, and a thousand other accidents; and the nature of the curves according to æsthetic laws. It is in these infinite fields that the invention of the architect is permitted to expatiate, but not in the alteration of primitive forms.

§ VI. But to proceed. It will doubtless appear to the reader, that, even allowing for some of these permissible variations in the curve or slope of X, neither the form at b, nor any approximation to that form, would be sufficiently undercut to keep the rain from running back upon it. This is true; but we have to consider that the cornice, as the close of the wall’s life, is of all its features that which is best fitted for honor and ornament. It has been esteemed so by almost all builders, and has been lavishly decorated in modes hereafter to be considered. But it is evident that, as it is high above the eye, the fittest place to receive the decoration is the slope of X, which is inclined towards the spectator; and if we cut away or hollow out this slope more than we have done at b, all decoration will be hid in the shadow. If, therefore, the climate be fine, and rain of long continuance not to be dreaded, we shall not hollow the stone X further, adopting the curve at b merely as the most protective in our power. But if the climate be one in which rain is frequent and dangerous, as in alternations with frost, we may be compelled to consider the cornice in a character distinctly protective, and to hollow out X farther, so as to enable it thoroughly to accomplish its purpose. A cornice thus treated loses its character as the crown or honor of the wall, takes the office of its protector, and is called a DRIPSTONE. The dripstone is naturally the attribute of Northern buildings, and therefore especially of Gothic architecture; the true cornice is the attribute of Southern buildings, and therefore of Greek and Italian architecture; and it is one of their peculiar beauties, and eminent features of superiority.

§ VII. Before passing to the dripstone, however, let us examine a little farther into the nature of the true cornice. We cannot, indeed, render either of the forms b or c, Fig. V., perfectly protective from rain, but we can help them a little in their duty by a slight advance of their upper ledge. This, with the form b, we can best manage by cutting off the sharp upper point of its curve, which is evidently weak and useless; and we shall have the form f. By a slight advance of the upper stone c, we shall have the parallel form g.

These two cornices, f and g, are characteristic of early Byzantine work, and are found on all the most lovely examples of it in Venice. The type a is rarer, but occurs pure in the most exquisite piece of composition in Venice—the northern portico of St. Mark’s; and will be given in due time.

§ VIII. Now the reader has doubtless noticed that these forms of cornice result, from considerations of fitness and necessity, far more neatly and decisively than the forms of the base, which we left only very generally determined. The reason is, that there are many ways of building foundations, and many good ways, dependent upon the peculiar accidents of the ground and nature of accessible materials. There is also room to spare in width, and a chance of a part of the arrangement being concealed by the ground, so as to modify height. But we have no room to spare in width on the top of a wall, and all that we do must be thoroughly visible; and we can but have to deal with bricks, or stones of a certain degree of fineness, and not with mere gravel, or sand, or clay,—so that as the conditions are limited, the forms become determined; and our steps will be more clear and certain the farther we advance. The sources of a river are usually half lost among moss and pebbles, and its first movements doubtful in direction; but, as the current gathers force, its banks are determined, and its branches are numbered.

§ IX. So far of the true cornice: we have still to determine the form of the dripstone.

Fig. VI.

We go back to our primal type or root of cornice, a of Fig. V. We take this at a in Fig. VI., and we are to consider it entirely as a protection against rain. Now the only way in which the rain can be kept from running back on the slope of X is by a bold hollowing out of it upwards, b. But clearly, by thus doing, we shall so weaken the projecting part of it that the least shock would break it at the neck, c; we must therefore cut the whole out of one stone, which will give us the form d. That the water may not lodge on the upper ledge of this, we had better round it off; and it will better protect the joint at the bottom of the slope if we let the stone project over it in a roll, cutting the recess deeper above. These two changes are made in e: e is the type of dripstones; the projecting part being, however, more or less rounded into an approximation to the shape of a falcon’s beak, and often reaching it completely. But the essential part of the arrangement is the up and under cutting of the curve. Wherever we find this, we are sure that the climate is wet, or that the builders have been bred in a wet country, and that the rest of the building will be prepared for rough weather. The up cutting of the curve is sometimes all the distinction between the mouldings of far-distant countries and utterly strange nations.

Fig. VII.

Fig. VII. representing a moulding with an outer and inner curve, the latter undercut. Take the outer line, and this moulding is one constant in Venice, in architecture traceable to Arabian types, and chiefly to the early mosques of Cairo. But take the inner line; it is a dripstone at Salisbury. In that narrow interval between the curves there is, when we read it rightly, an expression of another and mightier curve,—the orbed sweep of the earth and sea, between the desert of the Pyramids, and the green and level fields through which the clear streams of Sarum wind so slowly.

Fig. VIII.

And so delicate is the test, that though pure cornices are often found in the north,—borrowed from classical models,—so surely as we find a true dripstone moulding in the South, the influence of Northern builders has been at work; and this will be one of the principal evidences which I shall use in detecting Lombard influence on Arab work; for the true Byzantine and Arab mouldings are all open to the sky and light, but the Lombards brought with them from the North the fear of rain, and in all the Lombardic Gothic we instantly recognize the shadowy dripstone: a, Fig. VIII., is from a noble fragment at Milan, in the Piazza dei Mercanti; b, from the Broletto of Como. Compare them with c and d; both from Salisbury; e and f from Lisieux, Normandy; g and h from Wenlock Abbey, Shropshire.

§ X. The reader is now master of all that he need know about the construction of the general wall cornice, fitted either to become a crown of the wall, or to carry weight above. If, however, the weight above become considerable, it may be necessary to support the cornice at intervals with brackets; especially if it be required to project far, as well as to carry weight; as, for instance, if there be a gallery on top of the wall. This kind of bracket-cornice, deep or shallow, forms a separate family, essentially connected with roofs and galleries; for if there be no superincumbent weight, it is evidently absurd to put brackets to a plain cornice or dripstone (though this is sometimes done in carrying out a style); so that, as soon as we see a bracket put to a cornice, it implies, or should imply, that there is a roof or gallery above it. Hence this family of cornices I shall consider in connection with roofing, calling them “roof cornices,” while what we have hitherto examined are proper “wall cornices.” The roof cornice and wall cornice are therefore treated in division D.

We are not, however, as yet nearly ready for our roof. We have only obtained that which was to be the object of our first division (A); we have got, that is to say, a general idea of a wall and of the three essential parts of a wall; and we have next, it will be remembered, to get an idea of a pier and the essential parts of a pier, which were to be the subjects of our second division (B).

CHAPTER VII.

THE PIER BASE

§ I. In § III. of Chap. III., it was stated that when a wall had to sustain an addition of vertical pressure, it was first fitted to sustain it by some addition to its own thickness; but if the pressure became very great, by being gathered up into Piers.

I must first make the reader understand what I mean by a wall’s being gathered up. Take a piece of tolerably thick drawing-paper, or thin Bristol board, five or six inches square. Set it on its edge on the table, and put a small octavo book on the edge or top of it, and it will bend instantly. Tear it into four strips all across, and roll up each strip tightly. Set these rolls on end on the table, and they will carry the small octavo perfectly well. Now the thickness or substance of the paper employed to carry the weight is exactly the same as it was before, only it is differently arranged, that is to say, “gathered up.”35 If therefore a wall be gathered up like the Bristol board, it will bear greater weight than it would if it remained a wall veil. The sticks into which you gather it are called Piers. A pier is a coagulated wall.

§ II. Now you cannot quite treat the wall as you did the Bristol board, and twist it up at once; but let us see how you can treat it. Let A, Fig. IX., be the plan of a wall which you have made inconveniently and expensively thick, and which still appears to be slightly too weak for what it must carry: divide it, as at B, into equal spaces, a, b, a, b, &c. Cut out a thin slice of it at every a on each side, and put the slices you cut out on at every b on each side, and you will have the plan at B, with exactly the same quantity of bricks. But your wall is now so much concentrated, that, if it was only slightly too weak before, it will be stronger now than it need be; so you may spare some of your space as well as your bricks by cutting off the corners of the thicker parts, as suppose c, c, c, c, at C: and you have now a series of square piers connected by a wall veil, which, on less space and with less materials, will do the work of the wall at A perfectly well.