Chapter VII: Part 7

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.

Having secured the first object--an arch of reduced pressure--the second, viz., the abutment of an increased resistance, was attained by the systematic development of the buttress--a feature very much neglected by the Romanesque builders; and, as the vaulting of a lofty nave could not be directly supported by the ordinary buttress, the arched or flying buttress was introduced, spanning the aisles and conveying the pressure to the buttresses beyond. That this was introduced for utility only, and not from taste, is proved by the attempts in early instances to conceal it; so that we may with certainty conclude that all these beautiful features of Gothic architecture originated not from taste or caprice, but from reasoning upon practical and urgently pressing constructional requirements, and that the beauties to which they gave rise proceeded from the application to them of the great principle of Gothic architecture, the decoration of constructive or useful features.

Let us, however, suppose for a moment that our building is not vaulted, but has timber roofs; there still remains an advantage in the use of the pointed arch. If it has, for instance, a central tower, the demand for an arch of reduced thrust is still greater than if the church had been vaulted, for the arms of the cross, from their reduced weight, are less effective as abutments.

The chancel arch, again, demands height, and the more so if it be wide, as in our own day is necessary. The nave arcades are better pointed than round, as are any others carrying any considerable weight. Buttresses remain necessary at the ends of the arcades, and are desirable as a steadiment to the outer walls, particularly where roofs without a direct tie are made use of, and are further useful as permitting the introduction of larger windows than might be safe without them. In all cases, indeed, where roofs or floors are so constructed as to concentrate pressure upon points, it is clear that buttresses are desirable; and when the efficient size cannot be given them without inconvenience or dissight, it is equally clear that the deficiency may be readily compensated by loading them with lofty pinnacles. It is wrong to use buttresses without any object but appearance, but there are numbers of cases where they are of great advantage, besides those in which we know them to be indispensable. If so many of our arched and vaulted buildings in these days were not mere pretences in lath and plaster, we should have more practical experience of the need of the buttress and of the pointed arch. I was once told by the English Commissioner in Scinde that the European engineers had difficulty in making the native builders there believe that any but a pointed arch will stand.

Let us now inquire as briefly as may be into the _rationale_ of _ribbed_ vaulting as distinguished from the _arris_ vaulting of the Roman and earlier Romanesque builders.

A groined vault does not of absolute necessity demand the use of ribs any more than the plain waggon-head vault. Even the latter was from an early period frequently divided into compartments or bays by transverse ribs, which were useful as a means of giving it rigidity; but in _groined_ vaulting these were of nearly constant use, both for the same reason, and because the vault, being reduced at its springing to so narrow a footing, required this additional strength. The arrises, however, or diagonal lines of intersection, were always left without ribs.

Why, then, was the custom changed? For two important reasons. The first was this: that the intersection forms naturally a feeble line, both from the difficulty, particularly with the rough materials usually employed, of making its construction sound; from its forming an arch of greatly increased width without corresponding increase of height: and from its reduction at the springing level to a pin’s point.

The second was of a more intricate nature, and requires to be explained more in detail. When the two intersecting vaults of a groin are similar and equal in their section, or when the section of one is the mathematical resultant of that of the other, the line of intersection falls in a _plane_. When vaulting, however, became general, all sorts of irregularly-formed spaces would have to be so covered, and would present problems of considerable difficulty, in which it would be impossible in all cases that the vaulting surfaces should be portions of cylinders or regular cylindroids, and in which the intersecting lines could not, without much twisting of the surfaces, be brought to fall into planes.

The introduction of the diagonal rib met both of these difficulties. It strengthened the weak angle and gave it a substantial footing; and it at the same time gave to the lines of intersection a certain degree of independence of the vaulting surfaces; so that, instead of the surfaces governing the intersection, they were thenceforth governed by the ribs, and the latter could be made to fall into planes, and to avoid unsightly forms even in vaulting spaces of the most irregular and abnormal forms.

The substitution of the rib for the arris worked as great a revolution in the principles of vaulted construction as did the pointed arch itself. Nothing in the way of vaulting was now impracticable or unsightly; the architect was absolutely master of his work, and could do what he liked with it. The facilities it offers are quite marvellous in the eyes of the modern practical man when once they are opened to them. I have myself found one of the most practical men I ever met with, who had for years taken the leading management of the business of the greatest builder of our day, though hitherto uninitiated in Gothic construction, almost in ecstasies at finding a difficult problem in vaulting he had been puzzled over for days and making models of in vain, solved in an instant by seeing the absolute liberty of action exercised in a similar case in Westminster Abbey. The old builders themselves perfectly luxuriated in their newly-discovered liberty: not only could they vault spaces of any conceivable plan, every dimension of it varying, and the difficulties increased by the necessity of pushing up windows in its sides in all kinds of difficult positions, but they could make the result so pleasing and apparently so straightforward and natural, that not one observer out of a thousand ever finds out that there was any difficulty to be got over at all. Sometimes, indeed, we find them rejoicing so much in their freedom as to set themselves needless puzzles for the very luxury of solving them. There is a most remarkable instance of this in the crypt under Glasgow Cathedral, where the pillars which support the floor have been placed in a variety of intricate positions for no reason, apparently, but to produce curious perplexities in the vaulting and create strange problems, for the mere pleasure to be derived from their solution and the beauty of the puzzle when solved.[59]

It has been argued that the Gothic vault is less refined than some of the previous forms, because less strictly mathematical; that a refined system of construction should in all cases possess an exact mathematical solution, though the builder may, when once master of the true theory, depart from it in execution; that the work, in short, though irregular in execution, should be perfect and mathematically accurate in its theoretical type.

I agree with this doctrine in the main; but I hold that the Gothic vault complies with its conditions.

The square groined vault, with semicircular arches, is perfect in its theory, and gives elliptical arches for its arris lines. The same, if vaulted with the pointed arch, is equally true in theory, for the diagonal ribs may be pointed arches, formed each of portions of two ellipses. The oblong vault, again, is perfect if the wide arch is a semicircle, the narrow one a vertical semi-ellipse, and the arrises horizontal semi-ellipses of the same height; but the ancients generally chose to stilt the narrow arch instead of using the vertical ellipse, and by doing so threw the diagonal arris out of the plane and out of shape; but the theoretical form remained, nevertheless, perfect. In like manner, if the same figure be vaulted across its widest span by a pointed vault, and if the narrow vault have a pointed arch composed of two portions of ellipses, and the intersections be of the same figure as resulting geometrically from the intersection of the two vaults, the theoretical form is perfect. Now, if in either case the architect thinks the elliptical pointed arches inferior in beauty to those composed of parts of circles, and by using ribs finds himself enabled to throw the error resulting from the substitution of the latter form into the vaulted surfaces where it will be invisible, surely he is only using that discretionary power of introducing irregularities upon a perfect theory which is claimed as his right; and this is exactly what the Gothic architects introduced.

The fact is that, besides its unpleasing form, especially when the major axis is vertical, the use of the ellipse entails such an annoying series of difficulties as greatly to increase the trouble and consequent cost of execution. The constant change of curvature, the troublesome methods of striking it, and of finding the true lines of the arch-joints, not to mention the mathematical fact that the same joint line is never true both for the extrados and intrados, and that, if the rib-mould remains unchanged in depth, the extrados and intrados cannot be both true ellipses at all; all these furnish quite sufficient practical reasons for its rejection in cases where not only is there no necessity but an abstract mathematical idea to be satisfied by its use, but the beauty of the work is greatly improved by dispensing with it.

Though the pointed arch was introduced from purely constructive reasons, there was another of a more æsthetical nature, which rendered its adoption more general when once introduced. It was a double one; not only did the general tendency towards lofty proportions render it necessary to make use of an arch more in harmony with the general feeling of the architecture, but the rejection of a fixed code of proportions for pillars and other parts demanded for the arch an equal power of varying its own proportions. The semicircular arch is absolute and invariable, and though the use of smaller segments would meet the case in one direction, there were no means of proportioning it to features of _increasing_ height. This was attempted both in Romanesque and Byzantine works by the expedient of _stilting_, but this is, after all, more a semblance than a reality. As in cases already cited, the mathematical solution of the problem is the ellipse; but only imagine anything so unpleasing as a series of elliptical arches placed the length-way upwards! Good taste would not suffer it. But the pointed arch at once met the difficulty. To illustrate my meaning, I will beg you to take an internal bay of a Norman cathedral (Fig. 146), and to suppose yourselves to have to increase its height throughout in the ratio of one-third (Fig. 147).

You first, after setting out your widths as in the original, increase the whole height and that of each storey by one-third; you then increase the pillars and the jambs of the triforium and clerestory windows in the same proportion: this brings you to a stand, for the arches, being semicircles, are invariable. Either you must leave them unaltered and throw all the extra height into the wall above them, or you must stilt them each to the extent of one-third of their height unless you can make use of an elastic arch which will change its proportion at pleasure. The ellipse occurs and meets the case, but it offends your eye. At length, however, the pointed arch suggests itself, and gets rid of the whole difficulty. So similar are a Romanesque and an Early Pointed bay in all other respects, that the change of proportion which I have described seems at once to effect the whole change in style.

Had the constructional motive alone existed, the pointed form would have been confined to arches of considerable span; but the demand for a variable arch adding æsthetic to the constructional claim, caused its speedy adoption in positions where strength alone would not have demanded it, though the semicircle, the plain segment, and the segmental pointed arch, were, at all subsequent periods of the style, used side by side with the true pointed form.

I have been the more particular in showing the true reasons for the change in the form of the arch, because the great majority of writers treat it purely as a matter of taste and of altered fashion; indeed, some excellent writers on the history of Mediæval architecture have strangely imagined that the pointed arch had a greater outward thrust than the round, and that the increased projection of the buttresses was necessitated by its use, instead of the two being simultaneously introduced as a double means of avoiding the evils experienced from the great thrust of the round arch and the small buttresses by which it had, during the Romanesque period, been accompanied.

I will now close my present lecture, but hope in the next to carry on the same inquiry into a number of other details, as well as into the general spirit and principles of the architecture of which I am treating, and to add some practical remarks on the application of the _rationale_ thus traced out to our present revival of the style, and such developments as it may give rise to.

LECTURE VII.

The Rationale of Gothic Architecture--_Continued_.

The bases of a thirteenth century church indicate the plan and
construction of the vaulting--The system of mouldings--Windows,
their development--Rationale of stained glass--A general principle
of ornamentation common to all good architecture--The roof--Secular
buildings--Cloth market Yprès--Warehouses, Nuremburg--Windows in
secular and ecclesiastical buildings--Trabeated architecture in its
truest forms--Fireplaces--Chimney-shafts--Oriel and Dormer
windows--Ceilings--Subordination of external design to internal
requirements--Designs adapted to the materials most readily
obtained--Conditions demanded of our future architecture--Gothic
architecture well fitted to unite these conditions.

In my last lecture I traced out the _rationale_ of a number of the leading features, both of Romanesque as distinguished from Roman architecture, and subsequently of Gothic as distinguished from Romanesque. I will endeavour to avoid wearying you by carrying the inquiry into too great a multiplicity of details, but I must, nevertheless, ask your indulgence while I pursue them somewhat further than I have yet done.

Nothing would, perhaps, do more to show the reasonableness of the various developments in question than to trace out the details of the vaulting system; to show the varieties it exhibited in different countries and provinces and at different periods, the various modes adopted for effecting a given purpose and the many mechanical and other difficulties to be contended with, and the methods adopted of meeting them. This is, however, so extensive and so intricate a subject, that, if I had devoted these two lectures exclusively to it, I could barely have done it justice. I will, therefore, at present content myself with referring those of you who are anxious to make yourselves acquainted with it, to an admirable and elaborate essay on the subject by Professor Willis, in the Transactions of the Institute of British Architects, and to the article “Construction,” in the fourth volume of Viollet le Duc’s Dictionary. No one who has not gone carefully and practically into the subject can have any idea of the amount of forethought which it demands; so much so that, as Viollet le Duc says, the design for a vaulted building has to be commenced at the top and worked downwards; and we may often form a pretty correct idea, from the bases of a thirteenth century church, of what was the plan and construction of its vaulting.

This principle of designing each part from the first with reference to its ultimate intention is very strongly marked in French works of the twelfth and thirteenth centuries, and in those of the transitional period in England. The form, not only of the capital, but even of the base of each shaft, usually indicates the direction of the arched rib or order which it is destined to carry.

This was, however, lost in English works on the introduction of the circular abacus, and I must say that much expression and emphasis was lost with it. Not only, indeed, did the abacus in French work face or point in the direction of the arched rib, but its plan was often made to fit to it in the most direct manner, and even the direction of the principal stalks of the foliage had reference to the supported rib (Fig. 148).

The system of moulding, again, follows out the same laws of reason. An arch-moulding, for instance, is founded on what is supposed to be the original section of the order or rib. Thus, if the normal section of the rib be square, the section of the mouldings is made to fit to that figure (Fig. 149); if chamfered or a part of an octagon, the mouldings, again, fit to it (Fig. 150); the abacus in each case taking the normal plan of the ribs.

As to æsthetical forms, the mouldings were studiously arranged so as to produce in some parts the greatest contrasts, in others the most elegant gradations of light and shade. The heaviness of large roll mouldings was often relieved by fillets or by raised edges or “keels,” by which diversity was gained without loss of mass (Fig. 151).

Hollows, again, were relieved by the insertion of sparkling ornaments, such as the toothed ornament, the rosette, the ball-flower, the four-leaved flower, and many others; and in other instances by the introduction of bands of foliage. The sections of moulding differed entirely from those of Roman architecture, being far more free and less mechanical, and at once more delicate in feeling and more carefully studied with reference to light and shade. They resembled Greek mouldings, in fact, far more than Roman.

Enriched mouldings differed from the usual practice in antique work in this respect, that the enrichment was added to instead of being cut out of the original moulding; its practical use being to strengthen the hollows rather then to enrich the rounds. In this respect the practice of the Romanesque builder had been different; and perhaps a union of the two systems would be better than a close adherence to either.

Mouldings which receive much rain, as copings, cills, tops of cornices etc., were very much more sloped than in Classic work, so as to throw off the wet more rapidly. The custom in modern Classic buildings, where the stone is not very hard, of putting lead on the upper surface, as well as the damage often sustained when this is neglected, show the reasonableness of this increased slope. They had to do with a more rainy climate, and generally with softer stone, than the ancients, and they designed their work accordingly. The under sides, again, of projecting mouldings, as string-courses, drip-stones, water-tables, cills, etc., were carefully designed so as to prevent the wet from running round them. Base mouldings round buildings were designed in such a manner as both really and apparently to give it a substantial footing, and at the same time to add greatly to its beauty; many of them are as noble combinations as could easily be conceived.[60]

In short, it may be asserted, without fear of contradiction, that in no style of architecture has a system of moulding been generated so full of variety and so capable of suiting itself to every position; and not only to provide for the practical demands of each position, but to give to each just that kind of effect which it most demanded.

Let us now proceed to consider the _window_. In the days of ancient Greece, and in the earlier days of Rome, windows were necessarily kept in a very undeveloped form, through the non-existence of window glass; so much so, that in Classic architecture the window seems a thing shunned as an unhappy necessity; and the imperfect manufacture and dearness of this material, no doubt, influenced, in a considerable degree, the architecture of the later Roman and the immediately succeeding periods. In churches and other vaulted buildings, another cause would lead to the use, during the last-named (_i.e._, the Romanesque) period, of as small windows as would just answer the purpose. The unaided thickness and the whole length of the wall being relied on for the abutment of the vaulting, it naturally followed that perforations were as much avoided as possible, as tending to reduce the abutting mass. Accordingly, as buttresses increased in projection, greater and greater openings in the curtain wall were ventured on, simply because there was strength sufficient to admit of them, till, when Pointed architecture received its full development, and the pressure of the vaults was entirely concentrated upon the buttresses, the whole intervening space might, if needful, be converted into windows.

Simultaneously with this change, the increasing use of stained glass _necessitated_ a corresponding increase in the area of window opening, so that we have one development _facilitating_, and the other _rendering necessary_, the constant enlargement and multiplication of the windows.

The _primâ facie_ mode of obtaining increased window light would be by widening the openings; but as this, if carried too far, would at once injure the beauty of the window and cause inconvenience in glazing it, the more usual course adopted was to increase the number. Hence the couplets, triplets, and more numerous groups of the Early English windows. These groups, when placed in a side wall and under a level roof-plate, would naturally assume the form of arcades of equal height; but when under a gable, an arched roof, or a vaulted bay, they increased in height towards the centre,--thus giving us the two most familiar forms of grouping. The sections of the jambs were arranged (as in the earlier period) in the manner best suited to the admission of light--care being taken externally to avoid deep shadows upon the glass, and internally, to disperse the light as readily as possible through the building.

In domestic buildings, where windows have to serve the double purpose of admitting the light and facilitating external view, they were not usually grouped as above described, but were made wider in their openings, the unpleasant effect which might otherwise arise from it being obviated, and the glazing and opening of the window rendered more easy by the use of thin mullions or pillars dividing the window into two or more lights. This system offered advantages so obvious that it was very soon adopted for churches also; so that, instead of obtaining increased light, as heretofore, by the indefinite multiplication of comparatively small windows, it became customary now, _for the first time in the history of architecture_, to make windows of _any_ size which their position or utility might dictate; the whole end of a church and the entire bays of its flanks being occupied, if need be, by single windows.

Now, nothing could be more rational than this development. The mode of glazing in use was most conveniently applicable to spaces of moderate width. It is true that by the more extended use of iron it was then, as it has often been in modern times, applied to openings of 6, 8, or even 10 feet in width; but narrower spaces were much more convenient. The lights, however, at Westminster Abbey (which is one of the earlier buildings in which this kind of window is systematically used in this country), are 4½ feet wide, and in France they are generally much more. The prevailing practice of placing a massive pier between each of such lights was obviously imperfect. The concentration of pressure upon the buttresses now allowed of openings of almost any size; what, then, was more reasonable than to make extensive openings, and then to subdivide them by light mullions into compartments at once sightly and convenient? That this practice has sometimes, from caprice, been carried to a vicious excess in no degree militates against its _rationale_; indeed, with all our modern facilities for glazing and opening our windows, we continually find the same expedient resorted to for convenience, and invariably so when any extraordinary amount of light, and consequent width of window, is needed.

The next question which would arise is, how is the arch to be filled in? This we find done at first by a plate or tympanum of stone as thick as the depth of the mullions, each light being arched, and the tympanum pierced at pleasure with such openings as suited the builder’s taste; and, later on, we find these piercings connected together into those systematic groups which we call tracery; thus converting the window into a perfectly novel and most beautiful architectural feature.

As I shall have more to say on the subject of windows when we come to secular architecture, I will limit myself to two remarks. One is this; that in positions in which there is not much height, where there is no great load to be sustained, and where the termination of the wall internally and externally is horizontal, the Mediæval architects by no means held themselves bound to the arched form, but reserved perfect liberty to put square heads to their windows; the other is a passing remark on the _rationale of stained glass_. I do not conceive it to be simply a decoration or a means of adding rich colouring, but that it also arose from an unconscious feeling that it was necessary to the perfect effect of an architectural interior that it should be _self-inclosed_. In a living-room one wishes not only for admission of light, but for facility of looking out at the windows; and this necessity prevents us from seeing the windows well as architectural features, because the focus of the eye has constantly to be changed in passing from the window itself to the view beyond. In a church, on the contrary, you do not wish to look out at the window, and it is better that it should be filled with a medium only semi-transparent, and which, being at about the same distance from the eye with the surrounding architecture, at once does away with the necessity of a change of focus, and supplies a beautiful decoration to the medium by which that object is effected.

I have not yet noticed one of the leading features of the style, and one in which it assumes a character most peculiarly its own: I mean the _roof_.

All previous styles of architecture with which we are acquainted, having originated in Southern countries, had roofs of a low pitch. I have no doubt that in many of those countries there were occasions in which a higher pitch would have answered better; but as the lower line harmonised better with the generally horizontal lines of their architecture, and was found to answer, they naturally adopted it. The Romanesque architecture of Southern Europe had also somewhat low roofs, and when first imported into Germany the roofs were by no means high. Gradually, however, as men forgot its connection with Italy, and viewed it as belonging to themselves, they would naturally use with it the form of roof they had found most serviceable and were most accustomed to in their ordinary buildings; and thus the high roof of the North became engrafted upon the Romanesque style, and became conspicuous feature in external architecture. Happily this change harmonised well with its general character. The arch seemed to suggest a higher pitch of roof than did trabeated construction, and when greater height was generally introduced, and the pointed arch took the place of the round, the high pitch of the roof would be found better to harmonise with it.

I view, then, the high roof as partly the result of climate and partly of the æsthetic tendency of the style. But is it to be considered as an essential characteristic of Gothic architecture? By no means. The true characteristic of the style is _liberty_; and in the roof, as in every other feature, perfect freedom is reserved; so that we find roofs varying from almost perfect flatness to a very high pitch, a preference being given, _cæteris paribus_, to the high roof where there was not some decided objection to its use.

In internal construction also the roof was founded on rational principles, good construction being always considered before beauty, but the latter made very generally to result from it.

Gothic timber roofs would form a subject which could hardly be done justice to under one or two lectures, so I will not go farther into them now. Modern carpentry has shown us how to construct roofs with less timber than was used in these structures (there was then less necessity for the economy of timber), but we have never done anything to compete with the noble pieces of ornamented carpentering bequeathed to us by our Mediæval forefathers. As to covering of roofs, I may just mention, in passing, that though the Mediæval builders made use of every material which it is customary to use for this purpose, there are several which cannot be made use of with any but a high pitch, and are therefore unusable with low roofs such as are used in other styles, as, for instance, plain tiles, ordinary stone slate, shingle, and thatch.

The next point in the _rationale_ of Gothic architecture is one which I by no means claim as its peculiar property, inasmuch as it is common to all _good_ architecture, though certainly our style is somewhat pre-eminent in its adoption of it. I refer to that general principle of ornamentation which trusts mainly for beauty to the useful and constructive features of the building, rather than to those which are introduced directly for appearance.

Thus, in a noble Gothic building, the ornamental character arises from a greater or less richness in the _doorways_, in the _windows_, the _buttresses_, the _cornices_, _parapets_, or other parts needful for the uses or construction of the building. This belongs to all noble architecture, but is more thoroughly, I think, carried out in Gothic than in other styles, and perhaps less so in modern Italian, especially in what is commonly called Paladian, than in any other. I do not lay claim to it as an argument in favour of one style above another, for all _ought_ to possess it alike; but the absence of it in a very great deal of modern architecture is at least a proof that much reformation is needed among ourselves; and the strong degree in which it was adopted as a maxim by the Gothic architects is a proof of the reasonableness of the principles on which they acted.

There are, of course, in all styles of architecture decorations of a merely gratuitous kind, and when largeness of means leads to profusion, they are likely to be carried to excess; but in Gothic architecture of the best periods the beauty of a building (after good proportion, outline, etc., are secured) depends not on this deliberate ornamentation, but on the artistic treatment of the necessary features. Whatever parts were dictated by practical necessity were the chief objects on which decoration was expended, and to which the architect trusted for the beauty of his building.

More especially was it, _par eminence_, a _window_ style. Of all the objects provided for, the _admission of light_ was the first and chiefest; accordingly, the window was made, both within and without, the leading source of beauty. It is by the design of the _windows_ that we define the gradations of style. It is chiefly by the _windows_ that we describe a building, and the first question asked about a Gothic building generally relates to its _windows_. On them, therefore, was expended a large portion of the architectural decoration. How marvellous, then, is the inconsistency which we meet with!--people with one breath objecting to Gothic architecture--the offspring of Northern climes--as not admitting light enough, and urging the use of Southern architecture to obviate the imagined defect; and then telling you of the beauties of a modern building,[61] the great characteristic of which is, that its principal façade has no windows at all!

Next to the windows, the _doorways_ claim the most careful attention. Indeed, in some respects, they had the precedence, inasmuch as of all parts of a building the doorway is that which challenges the closest inspection. The decorations, consequently, of doorways are those which contain the greatest amount of actual sculptured art. It is a great principle to place sculpture where it will be best seen; and as every one who enters a building must of necessity obtain a close view of the doorways, they were naturally made the great vehicles for sculpture. In France especially, every part of the doorway frequently is sculptured. Take, for example, the western portals of Amiens: the pedestal or basement of the jambs is decorated with medallions, illustrating Bible history by bas-reliefs; the jambs contain colossal statues of saints; the central pillar of the great double doorway contains the chief statue; the tympanum is filled with subjects, and the orders of the arch with angelic figures; so that the entire doorways are alive with sculpture.

The buttresses, again, those naturally uncouth projections--mere inert masses to resist the pressure from within--are rendered beautiful by their stately proportions and architectural details, the niches and statues which adorn their receding stages, and the aspiring pinnacles by which they are crowned.

The stone roof-plate, enriched with mouldings and foliage, and, perhaps, supported on sculptured corbels, becomes the crowning horizontal feature; and the parapet--the defence of the workmen engaged on the roofs--is pierced into tracery, or forms a miniature arcade, giving delicacy and lightness of effect to the generally massive structure; while the bell-tower, raised high to make its voice heard from afar, becomes the culminating ornament of the whole exterior. So completely was it the recognised principle of the architecture to render the useful and constructive parts sources of decoration, that, where any deliberate decoration was made use of, it was often formed of imitations of constructional features, such as window tracery, arcades, gables, pinnacles, columns, etc.

I am not prepared to say that this is in itself to be applauded; indeed, I think it ought, at the least, to be kept within moderate limits; but it nevertheless owed its origin to the firm hold which the principle of rendering construction the leading source of decoration had upon the architects. Being accustomed to decorate construction, they got into the habit of using constructive forms as decorations.