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CHAPTER XIX.
SUPERIMPOSITION.
Оглавление§ I. The reader has now some knowledge of every feature of all possible architecture. Whatever the nature of the building which may be submitted to his criticism, if it be an edifice at all, if it be anything else than a mere heap of stones like a pyramid or breakwater, or than a large stone hewn into shape, like an obelisk, it will be instantly and easily resolvable into some of the parts which we have been hitherto considering: its pinnacles will separate themselves into their small shafts and roofs; its supporting members into shafts and arches, or walls penetrated by apertures of various shape, and supported by various kinds of buttresses. Respecting each of these several features I am certain that the reader feels himself prepared, by understanding their plain function, to form something like a reasonable and definite judgment, whether they be good or bad; and this right judgment of parts will, in most cases, lead him to just reverence or condemnation of the whole.
§ II. The various modes in which these parts are capable of combination, and the merits of buildings of different form and expression, are evidently not reducible into lists, nor to be estimated by general laws. The nobility of each building depends on its special fitness for its own purposes; and these purposes vary with every climate, every soil, and every national custom: nay, there were never, probably, two edifices erected in which some accidental difference of condition did not require some difference of plan or of structure; so that, respecting plan and distribution of parts, I do not hope to collect any universal law of right; but there are a few points necessary to be noticed respecting the means by which height is attained in buildings of various plans, and the expediency and methods of superimposition of one story or tier of architecture above another.
§ III. For, in the preceding inquiry, I have always supposed either that a single shaft would reach to the top of the building, or that the farther height required might be added in plain wall above the heads of the arches; whereas it may often be rather expedient to complete the entire lower series of arches, or finish the lower wall, with a bold string course or cornice, and build another series of shafts, or another wall, on the top of it.
§ IV. This superimposition is seen in its simplest form in the interior shafts of a Greek temple; and it has been largely used in nearly all countries where buildings have been meant for real service. Outcry has often been raised against it, but the thing is so sternly necessary that it has always forced itself into acceptance; and it would, therefore, be merely losing time to refute the arguments of those who have attempted its disparagement. Thus far, however, they have reason on their side, that if a building can be kept in one grand mass, without sacrificing either its visible or real adaptation to its objects, it is not well to divide it into stories until it has reached proportions too large to be justly measured by the eye. It ought then to be divided in order to mark its bulk; and decorative divisions are often possible, which rather increase than destroy the expression of general unity.
§ V. Superimposition, wisely practised, is of two kinds, directly contrary to each other, of weight on lightness, and of lightness on weight; while the superimposition of weight on weight, or lightness on lightness, is nearly always wrong.
1. Weight on lightness: I do not say weight on weakness. The superimposition of the human body on its limbs I call weight on lightness: the superimposition of the branches on a tree trunk I call lightness on weight: in both cases the support is fully adequate to the work, the form of support being regulated by the differences of requirement. Nothing in architecture is half so painful as the apparent want of sufficient support when the weight above is visibly passive: for all buildings are not passive; some seem to rise by their own strength, or float by their own buoyancy; a dome requires no visibility of support, one fancies it supported by the air. But passive architecture without help for its passiveness is unendurable. In a lately built house, No. 86, in Oxford Street, three huge stone pillars in the second story are carried apparently by the edges of three sheets of plate glass in the first. I hardly know anything to match the painfulness of this and some other of our shop structures, in which the iron-work is concealed; nor, even when it is apparent, can the eye ever feel satisfied of their security, when built, as at present, with fifty or sixty feet of wall above a rod of iron not the width of this page.
§ VI. The proper forms of this superimposition of weight on lightness have arisen, for the most part, from the necessity or desirableness, in many situations, of elevating the inhabited portions of buildings considerably above the ground level, especially those exposed to damp or inundation, and the consequent abandonment of the ground story as unserviceable, or else the surrender of it to public purposes. Thus, in many market and town houses, the ground story is left open as a general place of sheltered resort, and the enclosed apartments raised on pillars. In almost all warm countries the luxury, almost the necessity, of arcades to protect the passengers from the sun, and the desirableness of large space in the rooms above, lead to the same construction. Throughout the Venetian islet group, the houses seem to have been thus, in the first instance, universally built, all the older palaces appearing to have had the rez de chaussée perfectly open, the upper parts of the palace being sustained on magnificent arches, and the smaller houses sustained in the same manner on wooden piers, still retained in many of the cortiles, and exhibited characteristically throughout the main street of Murano. As ground became more valuable and house-room more scarce, these ground-floors were enclosed with wall veils between the original shafts, and so remain; but the type of the structure of the entire city is given in the Ducal Palace.
§ VII. To this kind of superimposition we owe the most picturesque street effects throughout the world, and the most graceful, as well as the most grotesque, buildings, from the many-shafted fantasy of the Alhambra (a building as beautiful in disposition as it is base in ornamentation) to the four-legged stolidity of the Swiss Chalet:60 nor these only, but great part of the effect of our cathedrals, in which, necessarily, the close triforium and clerestory walls are superimposed on the nave piers; perhaps with most majesty where with greatest simplicity, as in the old basilican types, and the noble cathedral of Pisa.
§ VIII. In order to the delightfulness and security of all such arrangements, this law must be observed:—that in proportion to the height of wall above them, the shafts are to be short. You may take your given height of wall, and turn any quantity of that wall into shaft that you like; but you must not turn it all into tall shafts, and then put more wall above. Thus, having a house five stories high, you may turn the lower story into shafts, and leave the four stories in wall; or the two lower stories into shafts, and leave three in wall; but, whatever you add to the shaft, you must take from the wall. Then also, of course, the shorter the shaft the thicker will be its proportionate, if not its actual, diameter. In the Ducal Palace of Venice the shortest shafts are always the thickest.61
§ IX. The second kind of superimposition, lightness on weight, is, in its most necessary use, of stories of houses one upon another, where, of course, wall veil is required in the lower ones, and has to support wall veil above, aided by as much of shaft structure as is attainable within the given limits. The greatest, if not the only, merit of the Roman and Renaissance Venetian architects is their graceful management of this kind of superimposition; sometimes of complete courses of external arches and shafts one above the other; sometimes of apertures with intermediate cornices at the levels of the floors, and large shafts from top to bottom of the building; always observing that the upper stories shall be at once lighter and richer than the lower ones. The entire value of such buildings depends upon the perfect and easy expression of the relative strength of the stories, and the unity obtained by the varieties of their proportions, while yet the fact of superimposition and separation by floors is frankly told.
§ X. In churches and other buildings in which there is no separation by floors, another kind of pure shaft superimposition is often used, in order to enable the builder to avail himself of short and slender shafts. It has been noted that these are often easily attainable, and of precious materials, when shafts large enough and strong enough to do the work at once, could not be obtained except at unjustifiable expense, and of coarse stone. The architect has then no choice but to arrange his work in successive stories; either frankly completing the arch work and cornice of each, and beginning a new story above it, which is the honester and nobler way, or else tying the stories together by supplementary shafts from floor to roof—the general practice of the Northern Gothic, and one which, unless most gracefully managed, gives the look of a scaffolding, with cross-poles tied to its uprights, to the whole clerestory wall. The best method is that which avoids all chance of the upright shafts being supposed continuous, by increasing their number and changing their places in the upper stories, so that the whole work branches from the ground like a tree. This is the superimposition of the Byzantine and the Pisan Romanesque; the most beautiful examples of it being, I think, the Southern portico of St. Mark’s, the church of S. Giovanni at Pistoja, and the apse of the cathedral of Pisa. In Renaissance work the two principles are equally distinct, though the shafts are (I think) always one above the other. The reader may see one of the best examples of the separately superimposed story in Whitehall (and another far inferior in St. Paul’s), and by turning himself round at Whitehall may compare with it the system of connecting shafts in the Treasury; though this is a singularly bad example, the window cornices of the first floor being like shelves in a cupboard, and cutting the mass of the building in two, in spite of the pillars.
§ XI. But this superimposition of lightness on weight is still more distinctly the system of many buildings of the kind which I have above called Architecture of Position, that is to say, architecture of which the greater part is intended merely to keep something in a peculiar position; as in light-houses, and many towers and belfries. The subject of spire and tower architecture, however, is so interesting and extensive, that I have thoughts of writing a detached essay upon it, and, at all events, cannot enter upon it here: but this much is enough for the reader to note for our present purpose, that, although many towers do in reality stand on piers or shafts, as the central towers of cathedrals, yet the expression of all of them, and the real structure of the best and strongest, are the elevation of gradually diminishing weight on massy or even solid foundation. Nevertheless, since the tower is in its origin a building for strength of defence, and faithfulness of watch, rather than splendor of aspect, its true expression is of just so much diminution of weight upwards as may be necessary to its fully balanced strength, not a jot more. There must be no light-headedness in your noble tower: impregnable foundation, wrathful crest, with the vizor down, and the dark vigilance seen through the clefts of it; not the filigree crown or embroidered cap. No towers are so grand as the square-browed ones, with massy cornices and rent battlements: next to these come the fantastic towers, with their various forms of steep roof; the best, not the cone, but the plain gable thrown very high; last of all in my mind (of good towers), those with spires or crowns, though these, of course, are fittest for ecclesiastical purposes, and capable of the richest ornament. The paltry four or eight pinnacled things we call towers in England (as in York Minster), are mere confectioner’s Gothic, and not worth classing.
§ XII. But, in all of them, this I believe to be a point of chief necessity—that they shall seem to stand, and shall verily stand, in their own strength; not by help of buttresses nor artful balancings on this side and on that. Your noble tower must need no help, must be sustained by no crutches, must give place to no suspicion of decrepitude. Its office may be to withstand war, look forth for tidings, or to point to heaven: but it must have in its own walls the strength to do this; it is to be itself a bulwark, not to be sustained by other bulwarks; to rise and look forth, “the tower of Lebanon that looketh toward Damascus,” like a stern sentinel, not like a child held up in its nurse’s arms. A tower may, indeed, have a kind of buttress, a projection, or subordinate tower at each of its angles; but these are to its main body like the satellites to a shaft, joined with its strength, and associated in its uprightness, part of the tower itself: exactly in the proportion in which they lose their massive unity with its body and assume the form of true buttress walls set on its angles, the tower loses its dignity.
§ XIII. These two characters, then, are common to all noble towers, however otherwise different in purpose or feature—the first, that they rise from massy foundation to lighter summits, frowning with battlements perhaps, but yet evidently more pierced and thinner in wall than beneath, and, in most ecclesiastical examples, divided into rich open work: the second, that whatever the form of the tower, it shall not appear to stand by help of buttresses. It follows from the first condition, as indeed it would have followed from ordinary æsthetic requirements, that we shall have continual variation in the arrangements of the stories, and the larger number of apertures towards the top—a condition exquisitely carried out in the old Lombardic towers, in which, however small they may be, the number of apertures is always regularly increased towards the summit; generally one window in the lowest stories, two in the second, then three, five, and six; often, also, one, two, four, and six, with beautiful symmetries of placing, not at present to our purpose. We may sufficiently exemplify the general laws of tower building by placing side by side, drawn to the same scale, a mediæval tower, in which most of them are simply and unaffectedly observed, and one of our own modern towers, in which every one of them is violated, in small space, convenient for comparison. (Plate VI.)
VI.
TYPES OF TOWERS.
BRITISH VENETIAN
§ XIV. The old tower is that of St. Mark’s at Venice, not a very perfect example, for its top is Renaissance, but as good Renaissance as there is in Venice; and it is fit for our present purpose, because it owes none of its effect to ornament. It is built as simply as it well can be to answer its purpose: no buttresses; no external features whatever, except some huts at the base, and the loggia, afterwards built, which, on purpose, I have not drawn; one bold square mass of brickwork; double walls, with an ascending inclined plane between them, with apertures as small as possible, and these only in necessary places, giving just the light required for ascending the stair or slope, not a ray more; and the weight of the whole relieved only by the double pilasters on the sides, sustaining small arches at the top of the mass, each decorated with the scallop or cockle shell, presently to be noticed as frequent in Renaissance ornament, and here, for once, thoroughly well applied. Then, when the necessary height is reached, the belfry is left open, as in the ordinary Romanesque campanile, only the shafts more slender, but severe and simple, and the whole crowned by as much spire as the tower would carry, to render it more serviceable as a landmark. The arrangement is repeated in numberless campaniles throughout Italy.
§ XV. The one beside it is one of those of the lately built college at Edinburgh. I have not taken it as worse than many others (just as I have not taken the St. Mark’s tower as better than many others); but it happens to compress our British system of tower building into small space. The Venetian tower rises 350 feet,62 and has no buttresses, though built of brick; the British tower rises 121 feet, and is built of stone, but is supposed to be incapable of standing without two huge buttresses on each angle. The St. Mark’s tower has a high sloping roof, but carries it simply, requiring no pinnacles at its angles; the British tower has no visible roof, but has four pinnacles for mere ornament. The Venetian tower has its lightest part at the top, and is massy at the base; the British tower has its lightest part at the base, and shuts up its windows into a mere arrowslit at the top. What the tower was built for at all must therefore, it seems to me, remain a mystery to every beholder; for surely no studious inhabitant of its upper chambers will be conceived to be pursuing his employments by the light of the single chink on each side; and, had it been intended for a belfry, the sound of its bells would have been as effectually prevented from getting out as the light from getting in.
§ XVI. In connexion with the subject of towers and of superimposition, one other feature, not conveniently to be omitted from our house-building, requires a moment’s notice—the staircase.
In modern houses it can hardly be considered an architectural feature, and is nearly always an ugly one, from its being apparently without support. And here I may not unfitly note the important distinction, which perhaps ought to have been dwelt upon in some places before now, between the marvellous and the perilous in apparent construction. There are many edifices which are awful or admirable in their height, and lightness, and boldness of form, respecting which, nevertheless, we have no fear that they should fall. Many a mighty dome and aërial aisle and arch may seem to stand, as I said, by miracle, but by steadfast miracle notwithstanding; there is no fear that the miracle should cease. We have a sense of inherent power in them, or, at all events, of concealed and mysterious provision for their safety. But in leaning towers, as of Pisa or Bologna, and in much minor architecture, passive architecture, of modern times, we feel that there is but a chance between the building and destruction; that there is no miraculous life in it, which animates it into security, but an obstinate, perhaps vain, resistance to immediate danger. The appearance of this is often as strong in small things as in large; in the sounding-boards of pulpits, for instance, when sustained by a single pillar behind them, so that one is in dread, during the whole sermon, of the preacher being crushed if a single nail should give way; and again, the modern geometrical unsupported staircase. There is great disadvantage, also, in the arrangement of this latter, when room is of value; and excessive ungracefulness in its awkward divisions of the passage walls, or windows. In mediæval architecture, where there was need of room, the staircase was spiral, and enclosed generally in an exterior tower, which added infinitely to the picturesque effect of the building; nor was the stair itself steeper nor less commodious than the ordinary compressed straight staircase of a modern dwelling-house. Many of the richest towers of domestic architecture owe their origin to this arrangement. In Italy the staircase is often in the open air, surrounding the interior court of the house, and giving access to its various galleries or loggias: in this case it is almost always supported by bold shafts and arches, and forms a most interesting additional feature of the cortile, but presents no peculiarity of construction requiring our present examination.
We may here, therefore, close our inquiries into the subject of construction; nor must the reader be dissatisfied with the simplicity or apparent barrenness of their present results. He will find, when he begins to apply them, that they are of more value than they now seem; but I have studiously avoided letting myself be drawn into any intricate question, because I wished to ask from the reader only so much attention as it seemed that even the most indifferent would not be unwilling to pay to a subject which is hourly becoming of greater practical interest. Evidently it would have been altogether beside the purpose of this essay to have entered deeply into the abstract science, or closely into the mechanical detail, of construction: both have been illustrated by writers far more capable of doing so than I, and may be studied at the reader’s discretion; all that has been here endeavored was the leading him to appeal to something like definite principle, and refer to the easily intelligible laws of convenience and necessity, whenever he found his judgment likely to be overborne by authority on the one hand, or dazzled by novelty on the other. If he has time to do more, and to follow out in all their brilliancy the mechanical inventions of the great engineers and architects of the day, I, in some sort, envy him, but must part company with him: for my way lies not along the viaduct, but down the quiet valley which its arches cross, nor through the tunnel, but up the hill-side which its cavern darkens, to see what gifts Nature will give us, and with what imagery she will fill our thoughts, that the stones we have ranged in rude order may now be touched with life; nor lose for ever, in their hewn nakedness, the voices they had of old, when the valley streamlet eddied round them in palpitating light, and the winds of the hill-side shook over them the shadows of the fern.
60 I have spent much of my life among the Alps; but I never pass, without some feeling of new surprise, the Chalet, standing on its four pegs (each topped with a flat stone), balanced in the fury of Alpine winds. It is not, perhaps, generally known that the chief use of the arrangement is not so much to raise the building above the snow, as to get a draught of wind beneath it, which may prevent the drift from rising against its sides.
61 Appendix 20, “Shafts of the Ducal Palace.”
62 I have taken Professor Willis’s estimate; there being discrepancy among various statements. I did not take the trouble to measure the height myself, the building being one which does not come within the range of our future inquiries; and its exact dimensions, even here, are of no importance as respects the question at issue.