Lectures on the rise and development of medieval architecture; vol. 1

by Sir George Gilbert Scott

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.