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.
[Illustration: Fig. 1.]
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).
[Illustration: Fig. 2.]
[Illustration: Fig. 3.]
[Illustration: 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).
[Illustration: 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.
[Illustration: Fig. 6.]
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.
[Illustration: Fig. 7.]
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:--1st, 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_.”
[Illustration: Fig. 8.]
[Illustration: Fig. 9.]
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).
[Illustration: 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.
[Illustration: Fig. 11.]
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.
[Illustration: Fig. 12.]
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.
[Illustration: Fig. 13.]
[Illustration: Fig. 14.]
On this plain and practical result M. Viollet le Duc (of whose admirable
essay on vaulting, together with those of Dr. Whewell and Professor
Willis, I have made free use) makes the following striking remarks:--
“It had required fifty years for the architects of the end of the
twelfth century to arrive, from the still Romanesque vaults of Autun and
Vezelay, at this great result; and from this moment the entire
construction of religious edifices was derived from the disposition of
the vaults; the form and dimension of the pillars--their spacing; the
window-openings--their width and height; the position and direction of
the buttresses--the importance of their pinnacler; the strength, the
number, and curvature of the arched buttresses; the disposing and the
carrying off the rain water; the system of covering,--all proceed from
the combination of the vaulting. The vaults govern the _ossature_ of the
monument to a point to which it would be impossible to raise it
otherwise than by commencing rigorously to plan them previously to
laying the first courses of the structure. This rule is so well
established that if we see a church of the thirteenth century destroyed
to the level of the bases, and of which the plan alone remains, we can
with certainty trace the plan of the vaults, and indicate the direction
of all the arches and their thickness. At the end of the fourteenth
century the rigour of the system is still more absolute; we can trace,
in examining the base of an edifice, not only the number and direction
of the arches of the vaults, and know their strength, but the number of
their mouldings and even their profiles. In the fifteenth century it is
the arches (mouldings) themselves which descend to the floor, and the
pillars are only vertical _fasces_ formed of all the members of these
arches. After this, we demand how is it that serious men have been able
to repulse, and still do repulse, the study of the architecture of the
Middle Ages as having been only produced by chance?”
It will be seen from what I have above stated that the order in which
the pointed arch was successively adopted for different parts of a
building, and the motives which led to its adoption, may be roughly
classified under the heads of _Statical_, _Geometrical_, and
_Æsthetical_, or positions in which it was demanded for soundness of
construction, for the mathematical agreement of parts, and for harmony
and beauty of effect.