IN the introductory lecture which I had the honour of reading before you last year, I endeavoured to give an outline of the varied claims of the architecture which was developed in our own and neighbouring countries during the Middle Ages, upon the study both of architects and lovers of art at the present day.

I will not recapitulate what I then said; but, presuming that by honouring me with your presence this evening you admit the subject to be well worthy of your attention, will crave your indulgence while I endeavour, at the risk of appearing to be going over a trite and almost exhausted subject, to give a brief outline of the rise and development of the architecture whose claims upon your study I then attempted to advocate.

My object is rather to trace out the re-awakening of art in the eleventh and following centuries from the slumber in which it had so long lain, than to chronicle its changes during the chaotic ages which followed the final catastrophe of the ancient world. Like the contemporary fable of the Seven Sleepers at Ephesus, its changes during this dreamy interval were but the turnings of the slumberer from the right side to the left, and little need is there to investigate such sluggish and disconnected movements. Our concern is rather with living and energetic art; and if we stop at all to inquire into its semi-dormant condition, it is rather for the sake of judging what were the elements of life which it retained, than from any really practical interest which attaches to its productions.

It is hardly possible to conceive of a state of things so utterly anomalous and contrary to all historical precedent as that of Western Europe after the deluge of Northern barbarism had annihilated the mightiest empire the world ever saw, and almost swept from the face of the earth the arts and literature which it had taken the whole period of human history to generate. Like the giant-slayers of old romance, the barbarous conquerors must have been filled with awe in contemplating the stupendous proportions of their now lifeless victim; and while wandering amidst the mighty monuments of the people they had overthrown, they must have been inspired with deep veneration for their intellectual power, and with ardent longings to inherit some portion of their skill—aspirations which, if we may judge from some of the structures erected by Theodoric, there can be little doubt would have been realised had not every wave as it subsided been succeeded by a fresh torrent of barbarism. The lamp of art was only saved from utter extinction by two surviving institutions—the Western Church and the Eastern Empire; the one seeming to absorb each succeeding wave of conquering barbarism, and the other to supply to each those elements of civilisation by which its fury was in its turn to be abated.

As might be expected from the circumstances of their position, the architectural efforts of the new races were founded on the basis of the Roman monuments, with whose vestiges they were on every hand surrounded, aided by friendly and continuous importations of the still living art of the Eastern Empire. Their elements were the Christianised Roman of the Western Basilica, and the newly-developed architecture of the Byzantine Church. Long, long, however, was it before any distinctive style was developed out of these elements. The efforts of Theodoric must be considered as rather Byzantine than Gothic; and for three centuries so little, if any, was the progress, that we find Charlemagne, the re-founder of the empire, actually despoiling the palace of the early Gothic king to use its architectural fragments in his own structures!

There can be no doubt, however, that the efforts made by Charlemagne for the revival of art would have soon produced some great results had he been followed by successors in any degree worthy of him; but so far from this, the nations he governed seem to have fallen back into almost worse barbarism than before, while the incursion of Northmen, Huns, and Saracens long repressed every effort after better things. We know little of the actual state of architecture during this melancholy period. The notion of Charlemagne having found a distinctive style of architecture in Lombardy, and having transplanted it to the banks of the Rhine, seems to be little more than a myth, though I think it not improbable that the Lombards had already taken some steps towards the formation of a new style.[2]

It is dubious whether a fragment of the structures erected by the Lombard kings now exists from which we may ascertain their style;[3], and though it is possible that the subsequent architecture may have been influenced by them in some degree, it is certain that the models which the Frankish emperor more especially followed were rather found in Byzantine Ravenna than in barbarous Lombardy, and the few remains of his architecture seem to be imitations of either Classic or Byzantine structures.

In England the works of this period were a very rude and unintelligible imitation of those of the same period at Rome, united with a strange translation into stone of their own timber structures, and occasionally enriched with that primitive kind of ornamentation which it is customary to call Runic.[4]

In the north of France it would not appear that the humbler class of churches were much better than those of which we find the remains in our own country. The remnants of one of the churches erected at that period on the site now occupied by Nôtre Dame at Paris, are debased Roman with Corinthian capitals; but the few remains of smaller churches—such as the old church at Beauvais—are not very unlike the Saxon structures in England. Of the latter it is but fair to state that the fragments which remain nearly all belong to merely rustic churches, and are hardly fair specimens of their style; they afford, however, sufficient proof of the rude state of art, though we have the witness of contemporary and succeeding historians to the fact that they were supposed and intended to be in the Roman style—meaning thereby, not that of ancient Rome, but that which prevailed at the period, and which we usually designate as the Basilican style.

The dawn of better things may be dated from the commencement of the tenth century, and may be mainly attributed to the consolidation of the German empire under the three first Othos (936-1002) and their immediate successors, and more especially to the fact of these emperors having had Lombardy equally with Germany, Switzerland, and portions of France under their sway, and thus in some degree uniting in one that vast expanse of country which extends from the banks of the Po to those of the Elbe.

Though Charlemagne had been the first to establish this mighty empire, and that on a yet grander scale, and may claim the title of the founder of modern civilisation, the seeds he had sown scarcely began to take root till the days of his German successors of the tenth and eleventh centuries. I say German successors, because the kings of France were his successors as Frankish kings, the others as German emperors; and from this time forward we find a sort of contest or competition ever going on, both in politics and arts, between those who represented him in those two capacities.

From the commencement of the tenth century we find one style of architecture for a time spreading over the plains of Lombardy, the valleys of Switzerland, and that of the Rhine, and extending itself over Saxony and all the civilised parts of Germany.

I do not say that the style was absolutely identical; but still it was essentially the same. It was promoted by the same all-pervading political influence; and there can be no doubt that the same ecclesiastics, and even the same artists, were engaged in carrying it out; and that even among those most remote from one another a constant interchange of views as to taste and construction was ever going on, while the differences which we observe would arise rather from those of climate, material, and proximity to the relics of ancient art, than from any essential or intended difference of style.

The force of the influence brought to bear at this period upon the furtherance of art may be judged of from the accounts we have of the schools of art and science established so far north as Hildesheim (in the neighbourhood of Brunswick and Hanover), by Bernward, Bishop of that see, at the close of the tenth and the commencement of the eleventh century. Bernward was tutor, and afterwards chancellor, to Otho III., and there are extant portions of an elaborate treatise on geometry from which he instructed that prince. He was himself skilled in many arts, as wall-painting, the illumination of MSS., mosaics, working in metals, cutting and setting precious stones, as well as in architecture itself; and it is said that “whenever he found a youth with a feeling for art, he took him into his laboratory, and instructed him with the greatest kindness in giving the required forms to stubborn metals, hard stone, wood, and ivory. The most artistic of these young men he always took with him when he travelled, especially when he went to Italy, that their taste might be improved by seeing masterly works of art, and hence be enabled to execute similar works at home.” Bernward rebuilt his cathedral and erected the church of St. Michael at Hildesheim (still existing); and of his works in metal there remain the gates and the spiral column (of which casts may be seen at the Crystal Palace), as well as the great corona, in the cathedral. I have dwelt the longer on these particulars because we happen to have more complete records of Bernward than of most of his contemporaries in art, and because the sphere of his operations was at a point so distant from the recognised centres of art; and when it is recollected that he was cotemporary with the erection of many of the great Romanesque cathedrals of Germany—as Mayence, Spire, and Bamberg, and of multitudes of less important churches (at the dedication of many of which he was present), and further, that he lived earlier than the erection of the Cathedral of Pisa, the Church of St. Mark at Venice, or St. Zeno at Verona—it will be seen at once how early and energetic was the architectural movement in Germany under those emperors who were also kings of Italy; and we need not wonder at the immense hold which the architecture, thus generated, had over the national mind of Germany.

It is probable that about the same period a style somewhat analogous to the Lombardo-Rhenish, though more strongly tinctured with Classic detail, was growing up in Provence and the other southern provinces of France, spreading itself northward, and thus meeting the German variety on the borders of Switzerland and in Burgundy. The dates, however, of buildings in those districts seem too indefinite to be argued upon with confidence, though it is certain that at a date somewhat later a very noble and refined variety of Romanesque, but with a strong Classic admixture, prevailed there.

About the same time the development of a distinctive style was promoted in the North by an apparently adverse cause. The Northmen, under Rollo, having ravaged and possessed themselves of an extensive province in the north of France, and having soon afterwards joined the Christian Church, set themselves vigorously about the task of repairing the sacrilege which, in the days of their ignorance, they had committed: nearly every ecclesiastical edifice in their new dominions had been destroyed, and never, perhaps, had a new and vigorous people a more perfect carte blanche for generating a new phase of architecture. We accordingly find that they soon covered their land with edifices; at first, it is true, rude and simple,[5] but subsequently possessing elements of dignity and massive grandeur of a very high order.

Of the central district of the Frankish monarchy at this period we have few architectural relics. The weakness of the Carlovingian monarchs, and the almost entire dismemberment of their dominions, left them, probably, little able to carry out great works; yet it cannot be doubted that the active genius of the race—surrounded as they were by the Romanesque developments of Lombardy, Provence, Rhineland, and Normandy—could not have failed to have produced works fully proportioned in merit to those of their neighbours, though during the period of subsequent greatness they were not deemed worthy to be retained.

We now arrive at the period at which the real subject of which I have undertaken to treat commences; and it may here be well to give a few moments’ consideration to the intrinsic nature of the art at this time being generated.

The early architecture of Rome,—locally occupying a position between the Greek colonies to the south and the Etruscan cities to the north,—partook, as it would seem probable, of the characteristics of both, and was more especially marked by the union of the Greek orders and their trabeated structure with the arched construction shadowed forth by the buildings of Etruria. The whole history of Roman architecture seems to evince a competition ever going on between these rival systems. It was at first an unequal contest, for the arcuated system had never, when first taken up by the Romans, had the advantage of being treated as the vehicle for architectural decoration—it was as yet mere construction; while the trabeated system had passed through a refining process of two thousand years’ duration, and had been brought by the Greeks to the highest pitch of beauty and perfection. The Roman structures display every step in this contest, some of their greatest structures being purely arcuated and merely constructive, others as purely trabeated—mere imitations of Grecian architecture; but the majority uniting both in different proportions, the Grecian element being very commonly little more than a decorative overlaying of the arched reality. As time moved on, the arched construction steadily gained ground: not only were openings arched over, but wide spaces vaulted both with domes, continuous cylindrical vaults, and those of the groined or intersecting form.

During the later ages of Pagan Rome, though architecture as a decorative art was on the wane, the triumph of arched construction became more and more complete. Columns hitherto used to support horizontal entablatures were employed directly to carry arches, the architrave being bent into a semicircle instead of lying horizontally upon the column; while spaces of gigantic span were covered with groined vaulting, some reaching to a width never since attempted.

In the Eastern empire the dome became subsequently the favourite form of vault, though, in each division of the empire, the arching over entire buildings in all its branches was practised with the greatest skill and success.

During the dark interval which followed the Gothic invasions, though constructive skill was immensely reduced, the preponderance of arcuated over trabeated architecture became yet more complete. The Greek element having during the later Roman period become merely decorative, and therefore no more than an artificial adjunct, it was natural that the overthrow of the ancient civilisation should at once sweep it away as a useless luxury, and that the real and useful portions of architecture should alone survive, though the actual skill in using them would be reduced. We find, accordingly, that during this interval architecture became purely arcuated, though in Western Europe the more difficult forms of arcuation, such as the vaulting over of large spaces, were usually avoided. This art, however, was never forgotten nor lost, but simply disused from diminution of skill, and the grand characteristic of the reawakening of architecture was the revival of these more difficult systems of construction; so much so, indeed, that nearly every structural change which we trace from the tenth to the thirteenth century arose, more or less, from the endeavour first to revive and then to carry on to higher and higher perfection the construction of arches and vaulting, and to elevate it from mere construction into the highest place among the means of producing beauty of decoration and sublimity of effect.

In the south of Italy the architecture continued all along to follow, in the main, the character of the Roman Basilica; and for a long period, it is probable, as I have before stated, that most of the Northern churches were rude imitations of this type; but gradually, in the countries north of the Po, a new form came over the architecture, which ever after distinguished Northern from Southern buildings, and which may be designated by the family name of Gothic, not only as being the progenitor of the style which has generally received that title, but as being actually in a great degree the style of the nations of Gothic extraction as distinguished from those of Roman parentage. This style has generally received the name of Romanesque, or Romane, to distinguish it from the pointed-arched style which succeeded it, but is by Mr. Fergusson more philosophically termed the round-arched Gothic, while he transfers the term Romanesque to the Christianised Roman or Basilican style. This is far more correct than the usual nomenclature; but as the latter is established by custom I shall not depart from it, but shall, for convenience, designate this round-arched Gothic style—as distinguished from the Christian Roman and from the Pointed style—by the customary name of Romanesque.

Of this style the following may be enumerated as the leading characteristics:—

1. Subordination of the arches.

2. Subdivision of piers to meet the subordination of arches.

3. Introduction of systems of moulding and decoration proper to subdivided arches.

4. The use of shafts or colonettes as means of decoration and accentuation.

5. The entire relinquishment of Classic proportions in the columns, which are henceforth proportioned in thickness to their load, irrespective of their height.

6. A system of decoration of its own, founded on Roman and Byzantine, but worked up into a new character, more or less independent of the original type, according to the locality, and to its removal from or proximity to antique monuments.

7. Great thickness of walls to resist the thrust of vaulting, aided by flat, pilaster-like buttresses in the principal planes of pressure.

8. In many cases—indeed, as a general rule—an air of gigantic massiveness in the entire construction.

9. The vaulting at first exactly accords with that of Roman buildings, embracing the barrel vault, the groined vault, and the dome, in nearly all the hitherto attained varieties. The arches always either semicircular or segmental.

The above characteristics are chiefly of a mechanical nature. The style possesses, however, sentiments of an infinitely nobler kind than anything which these mere material elements could impart. It possesses a sternness and dignity almost unearthly—a majestic severity of sentiment which seems, as it were, as if intended to rebuke the unpitying barbarity of the age, and to awe its rude and lawless spirits into obedience to the precepts of the Divine law. Its aspect is religious to the utmost extreme; but it expresses the stern uncompromising severity of religion rather than its more winning and elevating attributes—the asceticism of St. John the Baptist, the rebuker of sin and the preacher of repentance and of righteousness, rather than the spirituality of St. John the Evangelist, the preacher of Christian love, devotion, and praise. The sentiment they would express seems not so much “Worship the Lord in the beauty of holiness,” as “Fear before Him, all the earth;” and the task they prescribe to their ministers to be rather to proclaim “the day of vengeance” than “the acceptable year of the Lord”—less to “bind up the broken-hearted and comfort all that mourn,” than to “lift up their voice like a trumpet, and show the people their transgressions.”

This stern simplicity is not, however, universal, for from the first the Romanesque architects occasionally indulged in even rich ornamentation, and, at a later date, often carried it to profusion; yet, even in the richest decorations, they continued grave and severe—their lines were hard and precise, their foliage strong and harsh, and their figure sculpture (unless intended to be grotesque) was the very image of sternness—rude in art, but often of great dignity of expression; and though in an age like ours, of technical perfection and flippant criticism, it often provokes a smile, it was, in its own simple and untechnical age, well calculated to produce wholesome and solemnizing impressions.

This is the style of which we should first treat when attempting to trace the history of Mediæval architecture. It is a mistake to imagine Pointed architecture to be severed by a great gulf from the Romanesque—the Pointed Gothic from the Round: it is its legitimate offspring, or rather itself in a more advanced stage of its development. The change from the round-arched to the pointed-arched Gothic is no change of essential principles; it is but the carrying on to their inevitable results of the principles of refinement, purification, elevation, the perfecting of the construction, and the softening down of the asperity of expression, which were going on during the whole of the Romanesque period. Nearly every characteristic of Pointed architecture finds its type, or its perfected model, in the Romanesque. They are not two styles, but one—the earlier and the later phases of the same architecture; the latter being only the carrying on to perfection of the progression which had, during every moment of its dominion, and in every province of its empire, been uniformly going on in the former.

Though the refining process went unceasingly on during the whole history of Romanesque architecture and affected all its features, it would appear that the constant endeavours to bring to perfection its various systems of vaulting were among the greatest causes of the change from the Round to the Pointed style, I will, therefore, endeavour to give a concise outline of the changes in this branch of construction during the period under consideration.

The churches of Western Europe up to this time, like the early basilicas, were for the most part covered with timber roofs; and the task which the Romanesque builders proposed to themselves was to convert them into vaulted churches.

The most normal and readily invented vault is that of the continuous barrel or demi-cylindrical form, covering an oblong building from end to end, and the most readily conceived idea, where the building has to be roofed over such a vault, is to fill in the space between the arch and the triangle of the roof solid, and make it at once the ceiling of the room and the support of the roof covering. Such a vault, however, has considerable outward thrust, and, being heavily loaded at the crown, would require walls of great thickness to stand against it. Let us suppose it applied to the nave of a basilica in place of the timber roof, and it is obvious that, being balanced on two ranges of columns, it could not stand for a moment without some very effective contrivance in the construction of the aisles to buttress up the walls and pillars on which this barrel vault is to rest.

In the Baths of Diocletian, the Basilica of Maxentius, and other great Roman halls, this was met by cross walls pierced only by small archways, and placed at intervals, dividing the aisles into chambers, each of which was covered by a short barrel vault at right angles to that over the central space (Fig. 1). This, however, would be inconsistent with the uses of a church, and, indeed, applies to a groined rather than a barrel vault, though a very similar expedient was sometimes used by the Romanesque builders, by covering the aisles with cross barrel vaults, as those above described, supported by arches across the aisles, instead of by cross walls (Fig. 2). Another system was to cover the aisles by a half or little more than a half longitudinal barrel roof, forming a continuous arched buttress to the continuous central vault (Fig. 3). This gave them a perfectly vaulted building of trustworthy construction, provided only that the aisle walls were of sufficient strength. The barrel vaults were often both strengthened and their monotony relieved by arched ribs added to their thickness over each pillar of the nave, and repeated over the aisles, while these planes of extra strength were carried through to the exterior in the form of buttresses of small projection against the aisle walls (Fig. 4).

The builders of such churches were not, however, ignorant of the principles of the groined or intersecting vault formed by the inter-penetration of two demi-cylinders, and so largely used by the Romans. They did not use them in such buildings, because their main vault rising into the roof, they could not, under the same roof-plane, introduce the intersecting vaults,—though this had been effected in Roman structures by a series of cross gables over the cross vaults. In churches of the same kind, however, we find the groined vault used to carry a gallery in the aisles, all the rest remaining as before (Fig. 5).

It would appear that the obvious mechanical advantages it offered led at an early period, in the south of France, to the substitution of the pointed for the round arch in the great vault of churches of this construction; but I will suppose for the present the semicircle to be strictly adhered to. The great defect in such a church as I am supposing would be want of light in the nave from the absence of clerestory windows; and as such windows had been in use from the days of the earliest basilicas, this loss would be fully appreciated.

The first idea for obviating it was to lower the springing of the vault for the sake of bringing the thrust to bear upon a portion of the wall more capable of resisting it, and, by raising the nave relatively to its aisles, to obtain space for a range of small windows between the roof of the aisle and the springing of the main vault (Fig. 6). This, however, was a most unsatisfactory arrangement—it compromised the security of the structure, and gained but a very miserable range of lights.

This difficulty led to the somewhat unpalatable measure of lowering the springing of the main vault so much as to bring its crown below the level of the walls, and to convert it from a barrel into a groined vault. The springing being then level with the impinging line of the aisle roofs, a good abutment was obtained, while the cross vaults afforded ample space for clerestory windows (Fig. 7). I called this an unpalatable expedient for two reasons:—Ist, Because it involved the loss of the entire height of the roof as a part of the interior; and, secondly, because it led to the relinquishment of the incombustible construction, by rendering it impossible to make the vaulting to form the actual roof, and the consequent necessity for a timber roof above it. In a Northern climate, however, this was not an unmitigated loss, for a vault immediately under the roof-covering is always damp, and extremely difficult of repair; and we shall see that the loss of height was soon compensated for by a subsequent invention, while the substitution of a groined for a barrel vault not only introduced a beautiful in place of a comparatively dull form, but did away with the illogical characteristic of a continuous vault supported by detached pillars; the load being now collected together into points immediately over its supports. The same cause would naturally lead to the abandonment of the half-barrel vaulting of the aisles, the need of abutment being now not continuous, but in detached points. The aisles were consequently covered with groined vaults, a cross wall being raised upon their transverse arches, or arcs-doubleaux, which served as buttresses to the main vault, or would even carry external buttresses against the clerestory wall. The blank wall in the nave, caused by the space between the groining and roof of the aisles, was subsequently occupied by a gallery, so well known as the “triforium.”

A difficulty here presented itself, which I must state before proceeding further, as much stress had been laid upon it, and it unquestionably exercised a strong influence upon the subsequent arrangements. It is this: the simple groined vault being formed by the intersection of demi-cylinders, demanded that the space covered by it should be divided into perfect squares. Now, the aisles of a church being usually about half the width of the nave, it follows that the groining of both cannot be square. If those of the aisles are so, those of the main vault must be about twice as wide as they are long (Fig. 8); while if these are made square, those of the aisles will be twice as long as they are wide (Fig. 9). The first alternative was that most usually adopted north of the Alps, though the second was more frequent in Italy. The difficulty was how to groin these oblong bays. It was not, however, a new difficulty; it had occurred in Roman structures, where it was met by the simple expedient of raising the springing of the narrower vault so high, that its crown was level with that of the wider one. This answered the purpose, but it produced a most unpleasant line of intersection, reducing the vault, in fact, for a portion of its height, to a mere strip of the arc-doubleau, and giving a winding intersection for the remainder of the height, as two cylinders of unequal diameter do not intersect in a plane. The mathematical solution of the problem would have been to make the section of the narrower vault, an upright semi-ellipse; but this does not appear to have been at any period adopted, or, if at all, in exceptional cases only. The pointed arch would have been an approximate expedient, and its introduction has been very ingeniously attributed to this difficulty,—a theory to which I shall have again to allude.

Another solution of it would be to make all the arches semi-circles, but to raise up the crown of the vaults of a smaller diameter in a curve to meet the others, thus making it (roughly speaking) a portion of an annulus instead of a cylinder.

This had one great disadvantage: that it cut off a considerable portion of the space for the clerestory windows; or, if the level of the main vault was raised to obviate this, it became impossible to have a tiebeam to the roof. The system actually adopted in most instances would appear to have been a union of that last named with the Roman mode of stilting the narrow vaults, the difference of height being made up partly by raising its springing, and partly by elevating the crown (Fig. 10).

While these perplexities, however, were under consideration, several others arose, every one of which led to the introduction of features essential to the perfecting both of the style and construction. The first was the desire to elevate the central vault to a higher level, both for the sake of compensating for the loss sustained when it was brought down below the roof, and also to obtain a greater space for the clerestory windows. This involved, again, the difficulty as to abutment, through its raising the springing of the vault above the roof of the aisles. We have seen that, where reduced to a similar difficulty with the barrel vault, the architects of the south of France had at an earlier period resorted to the pointed vault as having less outward thrust: the same expedient was now had recourse to for groined vaulting, the main arches of which were now—towards the middle of the twelfth century—changed from the semicircle to the pointed arch. When the elevation of the clerestory above the aisles was but moderate, this was often found sufficient; but the construction was precarious, and in many instances failed, and a more perfect mode of meeting the case was required.

What was demanded was the power to elevate the clerestory with the main vault to any reasonable height above the aisle, without endangering the stability of the structure.

Here the recollection of an earlier expedient came to the rescue. It will be remembered that the early barrel vaults were buttressed by half barrel vaults over the aisles, thus doing away with the clerestory. A continuous vault demanded a continuous abutment; but, now that the pressure was concentrated into detached planes, it became sufficient that the abutment also should be in those planes; and though the continuous semi-vault would do away with clerestory windows, detached semi-arches would have no such effect. The thought accordingly occurred of erecting the arc-doubleau of the old semi-vault in open air as a buttress to the main vault of the groined church; and hence that much-admired, and, of course, also much-depreciated feature—the flying buttress. The pressure being concentrated upon points, it became also necessary to fortify those points by attached buttresses of considerable projection, such as we henceforth find to have become a leading external characteristic of Mediæval structures. The wall, in fact (where the system was carried to its extreme limits), became a mere curtain, needed rather for enclosure than for strength, and capable of being pierced with windows to any required extent; a liberty which the contemporaneous development of stained glass caused to be unhesitatingly taken advantage of.

I must, however, return to the vaulting, having overstepped my chronology by not yet noticing another most important invention. I mean the introduction of groin-ribs—those narrow arches erected under the lines of intersection of the vaults. The early groins had no ribs excepting the transverse ones, or arcs-doubleaux; the edges at which the vaults cut one another were left bare, and were the weakest parts of the construction; often but faintly marked, and not necessarily lying in planes. In more complicated vaults, such as now became necessary, this system could scarcely be continued; and the introduction of a stone rib, under every intersection, may be viewed as the crowning fact in the development of vaulting.

It is impossible to lay too much stress upon its importance, for it changed the entire geometrical system. Up to that time the construction of groining was wholly governed by the forms of the vaulting surfaces; the intersections being allowed to take their chance, and to present any irregularity of figure, while the wide surfaces of vaulting were apparently carried on mere pins’ points at the springing—correct enough as a mathematical figure, but ill calculated for strength. Now, however, the intersecting lines assumed the government of the construction, and the form of the surface was made to accommodate itself to them. They were always in planes,[6] and always true figures—usually arcs of circles; but the panels of vaulting became often irregular in their configuration, and could be twisted to meet contingent requirements without offending the eye; while the ribs, all meeting in a solid springer at the foot, brought down the pressure, and deposited it firmly upon the points of support.

It will be seen from the above that the pointed arch was not introduced into Mediæval structures from mere caprice—merely from seeing it elsewhere and taking a fancy to its form,—but from the necessities of construction, from its increased strength and diminished thrust. It was at first used for the main arch only of the greater vault. The same reason soon led to its introduction wherever great weight was to be carried, as under towers, etc.; but for all small arches the semicircle was long retained. I have alluded to the very beautiful theory that it was introduced for the side arches of oblong groins, simply as a means of obtaining arches of equal height with only half the span with those of the main vault. True it is, that, at a later date, it became most useful for this purpose. But a careful study of the monuments in which it is first systematically used clearly shows that its introduction was from statical, and neither geometrical nor merely æsthetical motives; for in the face of that theory we find the narrower arch or wall-rib remaining round long after the wider arch had become pointed (Fig. 11). Such is the case in nearly all the earlier of the French transitional churches, as at Noyon and at St. Germain des Pres, and we see the same at Canterbury. In most of these buildings the narrow arch is stilted and the crown of the cross vault raised up as before described, thus losing a part of the clerestory wall, a disadvantage obviated when the pointed arch became more frankly acknowledged.

Although, however, the pointed arch was actually adopted from simple necessities of construction, its advantages in all points of view soon became apparent. In an essentially arcuated style it becomes necessary not only to have the command of a form of arch capable of carrying the greatest weights and of requiring the least abutment, but it is essential to have at command an arch of variable proportions. It carries absurdity on the very face of it that, while able to give our piers a greater or a less degree of height at pleasure we should have no such power over the arch they sustain; not to mention the numerous cases in which we have to bring together arches of unequal span, and which nevertheless demand an equal height. The rules of harmony imperatively demand that the arch should be equally capable of modification in its proportions of height to width, with all other features of the architecture.

In the above outline of the history of vaulting I have, for the sake of simplicity, omitted two modes actually adopted to avoid the difficulty of oblong groining over naves. The first, which was common in German round-arched churches, was to make the vaulting of the nave simply to comprise two bays of the aisles, thus bringing the main vault equally into squares with those of the aisles. The second was the use of what Dr. Whewell has entitled sexpartite vaulting, and which is common both in France, Germany, and England (Fig. 12). It adopts the system last named, but subdivides the double bay by a triangular slip of vaulting (Figs. 13, 14). The real solution arose, however, from the free and simple use of the pointed arch, which gave the result which is seen at Westminster[7] and in nearly all the vaulted churches of the thirteenth century—the simple groined vault with arches of equal height, though the side arches are sometimes stilted, not from necessity, but merely to afford greater space for clerestory windows.