Part 15

The two great defects in the _rationale_ of their architecture were--first, that, as the conquerors of the world, the resources at their command were so unlimited that economy of material seems to have been almost dismissed from their consideration, and their principle of statics seems to have been rather that of passive and inert resistance than of equilibrium of forces; and, secondly, that, having adopted the artistic features of Greek architecture, they attempted to unite them with their own totally different system of construction, in a manner which cannot always be said to be consistent with reason.

When the nations of modern Europe began to emerge from the chaos of centuries, and to generate for themselves a new civilisation, their aim, as regards architecture, seems rather to have been to recover that of ancient Rome, than to generate a new style for themselves; but their limited resources, and unfamiliarity with what is now denominated “Classic” art, freed them from the tendency to follow their great masters in the two defects which I have mentioned. True, they often built with needless massiveness; but this was not the result of profuseness, but of want of experience; and when they imitated or re-used the details of Roman architecture they applied them with more regard to practical utility then to Classic precedent.

At first the Romanesque builders were at a low level both as to constructive and artistic skill; but all their efforts being directed to practical improvement, they, in course of time, succeeded in generating a very consistent round-arched style, in which every feature may be said to have resulted, in a greater or less degree, from practical reasoning on immediate requirements and on their experience of preceding defects.

The observations I have to offer on the developments thus reasoned out are intended to apply mainly to those of the countries north of the Alps, but may in many points be found to be of general application.

One of the first practical principles aimed at throughout the whole range of Mediæval architecture was so to arrange their designs as to facilitate the use of small materials, and to render themselves independent of the accident of having quarries at command which would supply vast blocks of stone. It happened that in the great seats of early art this was of less consequence, for Egypt, Syria, Greece, and Italy contain such quarries in tolerable abundance, though even the Romans resorted to concealed arches for the security of their architraves; but in Northern Europe, though building-stone in most parts abounds, it is quite exceptional to find it at once in blocks of great dimensions and of strength which would render it a trustworthy covering to openings of any considerable bearing. With all our increased facilities at the present day, we never find the trabeated system carried out in its integrity when on a large scale; either the middle stones of architraves are suspended by concealed arched joints, as is the custom here, or are visibly arched-jointed, as in France, or the entire architraves consist of brick arches plastered over, to mimic the construction they affect but cannot follow. Even in our Gothic buildings, where every facility exists for the use of moderate-sized stone, it is often with much difficulty that blocks of a size suited to all purposes can be obtained. Thus with the Houses of Parliament, after the whole kingdom had been ransacked by a geological commission, not only was the quarry they recommended summarily rejected as incapable of furnishing stone of any reasonable size, but the second quarry, which was adopted in its place, and which produced an admirable material, was, after a time, abandoned, and a third selected, the productions of which have, in other respects than size, proved so lamentably inferior. The fact is that it is only here and there that we find quarries uniting _quality_ and _size_ which suit even our moderate requirements; and if such is the case now, with all our mechanical advantages and facilities of transit, how much more must it have been felt in days when the mechanical appliances of the ancients had been in a great measure lost, and the Roman roads broken up, while the means which were to supply these deficiencies were yet in their infancy.

While, then, _at all times_ and _everywhere_, it is a desideratum to a rational system of construction that it should offer every facility for the use of ordinary and easily-obtained material, such was the case in a more than usual degree in those early ages of modern art.

Though the universal use of the arch by the Romanesque builders obviously promoted this object, it would not of necessity lead to its fullest attainment. Arches may be, and often are, constructed of enormous blocks of stone; and it had to be studied how to make good construction with small materials.

The most obvious means of doing this was by building the arches in _rims_, as we do our brick arches--a deep arch, consisting of several distinct arches laid one over the other, each forming the centre on which the next is built (Fig. 136). By this mode of building an arch of any degree of strength may be built of stones of the most moderate dimensions. This system, consequently, became general in the Romanesque buildings.

Now, a deep arch so constructed, and built square through the wall, has a heavy clumsy appearance, and forms a dark and cavern-like recess. You may ornament the voussoirs and vary their colour as you please, but still it is heavy, wanting in play of light and shade, and obstructive to the free passage of the rays of light. This was early felt and early obviated.

In an arch built in several rims, it is not necessary that any but the outer rim should be of the full width of the wall. This suggested the system of _sub-ordinating_ the rims, or recessing them, one behind the other, so as to divide the arch into what are called _orders_ (Fig. 137).

This gives us at once a new and beautiful mode of arching, economical, and adapted to all varieties of material, giving great play of light and shade, offering the greatest freedom for the admission of light, and suggesting (as we shall see) a perfectly new system of decoration.

This division of the arch into receding orders necessitated a corresponding form in the piers which supported it.

The first means of relieving the plainness of this block form was the introduction of an impost at the springing, defining the line which separates the pier from the arch (Fig. 138). Afterwards the orders of the jamb would receive pilaster capitals (Fig. 139), and finally decorative columns would be inserted in their place (Fig. 140), thus completing the general idea of the pier and arch as made use of during the Romanesque period.

The arch itself was at the same time subjected to various systems of decoration suited to its _normal_ construction.

It is clear that the extreme angles of the orders contribute but slightly to their strength. These might, therefore, be rounded, chamfered, or moulded at pleasure. It became common to form them into large rolls between two hollows, and also to cut the order into various mechanical or other forms, as zigzag, etc. etc., according to the fancy of the architect, from which arose the whole system of Romanesque arch-decoration; and as the junction of the arch with the wall above was but slightly marked by the change in the direction of the joints, a small projecting moulding was introduced between them, which we call the dripstone or label, which not only drew the line more emphatically but also served to prevent the water which ran down the face of the walls from discolouring the arch-mouldings.

It will readily be seen that this logical and reasonable mode of constructing arched openings would, when applied to arches carried on pillars, lead to the clustered column.

If the wall was not thick, the arches might certainly continue to be of one order, and the most natural mode of supporting them would then, as heretofore, be single columns. Where, however, the wall was so thick as to give it a clumsy look if the arch ran square through it, it would be divided into two orders, and would assume at its springing a cruciform plan. The impost must break round this figure; and though the column might still remain (and often did remain) round (Figs. 141, 142), the abacus only assuming the cross form, the most natural thing would be to form a complex pillar composed of four shafts united in one, each apparently supporting its own order of the arch (Fig. 143).

If the arch were divided into three orders, a more complex form suggested itself, containing eight shafts; and as the system was carried out, many other combinations arose not necessary to enumerate.

Thus we see that the adoption of the arched system of construction, unbiassed by any pre-existing laws of art, but aided only by the very rational desire to utilise the materials most abundantly provided by nature, led to two of the most important characteristics common to Romanesque and Gothic architecture, viz., the sub-ordinated arch and the clustered column, with the whole system of decoration derived from them; than which no two features can be pointed out which have been more richly fruitful of architectural forms the most original and beautiful.

Again, in the mode of bringing down the arch upon columns, the Romanesque builders exercised a sound discretion. The Greeks and Romans in their trabeated construction, reasonably enough, made their architraves only as wide as the upper diameter of their columns, so that whatever projection the capitals had beyond the shaft, they had the same beyond the architrave also. When, however, you substitute two arches for two architraves, you bring down the weight by two opposite forces; its footing on the capital, therefore, requires as much steadiment as possible.

The Romans, as many of their modern followers, were for a time so inconsistent as not only to limit the arch, like the architrave, to the thickness of the upper diameter of the column, but actually interposed, without a shadow of use, a bit of entablature between the column and the arch; thus, instead of doing all they could to give steadiness to the spring of the arch, they made it as tottering in its construction as possible. This was corrected by the Romans of the Lower Empire, and the arch was placed by them, as reason would dictate, directly upon the capital, or (still more sensibly) on a strong flat impost laid on the capital; and for this most reasonable step they have in after ages been pronounced barbarous! The Romanesque architects, taught by common sense rather than by precedent, followed their example. If they imitated or re-used the Corinthian capital, they laid upon its fragile abacus a more trustworthy impost, and to give greater steadiment to the foot of the arch they made it somewhat wider than the diameter of the column--a practice which pervades Mediæval architecture, and contributes greatly both to its good construction and its beauty.

The system of constructing _doorways_ is directly derived from what I have already described--as many recesses being given to the jambs as the arch has rims, and these decorated with columns if thought good. The head is often filled in with a tympanum supported by corbels in the jambs, both as a field for sculptured decoration, and to make the door itself square instead of arch-formed. If this is not done, the inner arches are made to spring from a higher level, to allow the doors to open without catching against them.

The windows show the same regard to reason. The inside is nearly always widely splayed, to spread the light equally in the room. The external recess depended partly on the degree of architectural character aimed at, and partly on the depth required for the arch. Where the openings were but narrow, and the resources small, one arch-rim would suffice; and this would often be chamfered at the edges, to prevent obstruction to light.

If the opening were wider, and so required a deeper arch, or if the architectural effect aimed at were greater, we find two or more such orders as the above, with, perhaps, columns supporting the outer ones; the receding orders, in either case, doing away with undue obstruction of light or view; the sill always well sloped, to throw off the water, and having usually a string-course below, to prevent it from running down and discolouring the walls. In all this, strict regard to practical reason and utility is manifest; every step is argued out on the basis of construction and requirement, and every decoration is founded on, and results from, the conclusions come to on these practical grounds.

In domestic architecture, if a window were beyond the width of a single casement, a small pillar was often interposed, and the inner order of the window was divided into two arches, while the outer one, if there were any, was in one, the casements or shutters falling into rebates in the back of the column, by which a window of double width, which would not otherwise be conveniently attainable was produced. In window-like openings in which glazing was not needed--as in triforiums, cloisters, and screens--this system was used for beauty where not demanded for the same reasons as in windows, and the subdivisions were often increased to three or four under one comprising arch.

In other instances of the same kind, where light arcading was needed, as in cloisters, and the wall was too thick to rest upon a single capital, two small columns were placed one behind another, or a sort of bar or double corbel placed on the capital of a single pillar to support the springer of the arch, for the sake of avoiding the use of thick piers, which were not needed for strength, and would obstruct view and light; and all these practical contrivances were made elements of beauty and varied effect.

Another legitimate exercise of reason on the part of the Romanesque builders, was the rejection of the fixed rules of proportion observed by the ancients between the diameter and height of their columns. These rules were good in their place, but they had been worked out for a totally different system; and we know that the ancients themselves were anything but as slavish in their adherence to them as their modern imitators. In a purely arcuated system, however, it became clear that such rules were out of place and inconsistent with reason. Circumstances, in a majority of cases, prescribed the height of a column, from reasons wholly irrespective of the question of its load. It followed, then, that the diameter must be regulated rather by the load than the height, so that every variety of proportion became admissible. Take, as an example, the crypt under the choir of York minster. Its height being prescribed by circumstances, and the portion of it required for the vaulting being fixed by the width of the arched bays, it followed that the height of the columns was also rigorously defined; but some of these columns had to carry those of the church above, and with them the whole superstructure, while others had no load but the vaulting of the crypt and the floor of the church. Surely, then, the simplest exercise of reason dictated that their diameters should vary with their load, irrespective of their height. The system of clustering columns both helped to moderate the extremes of such variation in proportion, and, at the same time, introduced still wider liberty; for, though a pier destined to carry a vast load might be subdivided, and its apparent proportions thus lightened, the individual shafts of which it was composed, not having each its own proper load, might be viewed as decorative only, and be made exceedingly thin for their height. The use of such thin shafts did not, however, originate in the Middle Ages. Canina shows in his work on _Domestic Architecture Decorated with Ornaments of a Light Form_, that it was frequent among the ancients, though not often adopted by modern Classic architects. Even for really constructive pillars it is admissible where the material is of remarkable strength, as in the case of metal columns, and, in a less degree, with those of marble or granite where the load is very small; but it is especially so where the columns are of a decorative rather than a functional character, in which case it is not only lawful, but correct, to show this by making them of slender proportions. The liberty, however, which I here defend, must, as all other liberty, be kept within reasonable bounds, and must be regulated by a correct eye and sound judgment.

Another sound exercise, as I think, of reason and liberty, which was universal among the Romanesque and Byzantine architects, was the departure from the rule of the ancients that all capitals and other recurring objects of a like nature should be worked to one and the same pattern. It may be that the unity of a colonnade, united by a single and unbroken entablature, demanded this. I am not finding fault with it in Grecian or Roman architecture; but where the capitals are separated by arches, or did not form a continuous range at all, the effect would be most painfully monotonous if the sculptured capitals were all alike, as if cast in a mould by the hundred. We accordingly find it established as a universal law that, though moulded or other mechanically-formed capitals might, if you please, be alike, no such slavery should be imposed upon the sculptor; but that he should have the fullest scope, within the reasonable limits suggested by the requirements and the general balance and harmony of mass and outline, for the freest exercise of his own imagination.

Now, though these and other developments of the Romanesque period were founded on a thoroughly practical and logical course of reasoning, it by no means follows that a perfected form of arcuated architecture had yet been arrived at, any more than that the decorative system had been brought into a thoroughly refined or artistic form.

Towards the middle of the twelfth century the efforts of the architects were redoubled towards the attainment of these two objects; and the advancement made, both in correcting defects in construction and refining the decorative system, were most strenuously followed up, and all improvements made were founded strictly on reason. The great constructive difficulty met with arose from the powerful outward pressure of the round arch when of great span or carrying any great load, and especially so when used in situations where it was difficult to give it any very massive abutment.

The cases of failure from this cause were most frequent; so much so, that besides the numerous instances recorded of buildings wholly or in part falling from the failure of the arches, we find among the buildings still remaining abundant evidences of the insufficiency of the round arches for their load, and of the abutments to resist their pressure. In ordinary architecture we cannot, as in bridges, viaducts, etc., give our arches an unlimited abutment proportioned to the pressure, whatever it may be; we are limited in our means of doing this by innumerable causes: thus, in a central tower, if the arms of the cross have aisles, the natural abutments of the tower arches are reduced to the frail aid of a continuous arcade upon detached pillars; and even if there are no aisles, the abutting walls are perforated with windows. The abutments, again, of a chancel arch are perforated either by arches or windows, while the gable over the arch loads it heavily at its weakest point. The abutment of an arch, again, has often to impinge upon a pier at half its height, as in the case of a nave arcade abutting upon the detached piers of a central tower. In all such situations the undue pressure of the round arch was found to be most prejudicial. Still more strongly was it felt where the nave was spanned by stone vaulting. The Romans had got over this, as in the Baths of Diocletian, by breaking the continuity of the aisles by vast abutting walls across them. But in a church this was impracticable. Its uses demanded continuity of aisle and moderation in the size of the pillars. Failures often occurred from these adverse causes, and the ingenuity of the architects was naturally directed to obviating the defect.

I have, in a previous lecture, described the series of tentative experiments, all of them dictated by constructive and practical requirements, by which it was attempted to avoid these difficulties. I will not weary you by recapitulating them. The two obvious desiderata were an arch of less pressure and an abutment of greater resistance; and these were the two objects aimed at in most of the succeeding developments. The first demand was met by the pointed arch; the second by the systematised use of the buttress, whether of the solid or arched description. It was perfectly well known that the outward thrust of an arch diminished as its height increased; that the resisting power of an abutment depended mainly on its extension in the direction of the pressure; and that where sufficient extension of abutment could not be obtained without inconvenience or dissight, the deficiency might be compensated by loading it from above: and by arguing on these three facts the constructive characteristics which distinguish Gothic from Romanesque, or the pointed-arched from the round-arched Gothic, were logically worked out.

The strictly mathematical mode of increasing the height of an arch would, I suppose, be by using a semi-ellipse, its major axis being vertical. The form is, however, most unpleasing to the eye and troublesome in execution, from its constant variation of curvature, so that by far the most natural and practical means of effecting the object is the adoption of an arch of two centres, or what is commonly called the “pointed arch.” We accordingly find, as I have shown by ample evidence in a previous lecture, that this form was in the first instance used just in those situations in which a reduction of outward pressure or an increased power of bearing weight were of the greatest importance. I have shown that this form was not adopted at first as a matter of taste, of fashion, or of fancy; nor even, as has been suggested by a highly talented writer, as a means of meeting the difficulties arising from the varied heights of the arches of vaulting, but simply from _structural_ and _mechanical_ necessity. It matters not whether the form was new or old, whether it occurred to them without external suggestion, or whether they saw it in the East, in their own intersecting arcades, or in the first proposition of Euclid. It was not the seeing of it in any such manner which caused its introduction, but the simple fact that they had arrived in the course of their constructive development at a practical problem of vital importance, which _absolutely demanded_ the pointed arch for its solution.

The first situations in which the pointed arch was substituted for the semicircle are the wide spanning arches of vaulting and the arches carrying central towers and gables. We next find it in the wide arches of nave arcades; and it is not, as a general rule, till it became customary in those positions where it was demanded for practical reasons, that it began to be used as a matter of taste in other positions.