GLASS OF THE LATER MIDDLE AGES IN WESTERN EUROPE
One of the chief glories of the later Middle Ages in Western Europe is
undoubtedly to be found in the stained glass windows of the churches.
Theophilus early in the twelfth century had already made himself master
of this art, which he regarded as essentially a French one. The
preparation of these _vitraux_ involved a knowledge of the process
either of spinning the molten _paraison_ or of opening out the cylinder
of glass, both comparatively late developments of the art of
glass-blowing. In the staining of the glass we know from extant
specimens what splendid results were obtained.
The composition of the window-glass of the thirteenth century is in
some ways remarkable. It contained as much as from 8 to 10 per cent. of
alumina, which we must regard as replacing in a measure the silica, for
this constituent falls to as low as 56 per cent., and we can hardly
otherwise account for the high percentage of the other bases—14 per
cent. of lime, 17 per cent. of potash, and often 3 or 4 per cent. of
iron. The result was a tough, somewhat horny glass, hard to work in
consequence of the short duration of the viscous stage during the
cooling. This was one reason for the smallness of the gatherings, and
the modest dimensions of the resultant discs. On the other hand, such
glass resists the action of the atmosphere better than any made
nowadays, and the large amount of potash present probably promoted the
brilliancy of the colours. From the earliest times the blue colouring
was given by cobalt, and this was never of a richer and purer tint than
in the twelfth century; already in the thirteenth copper was added to
correct a tendency to purple. The famous ruby red, which became rarer
after the thirteenth century until in the seventeenth the secret was
entirely lost, was produced by the partial reduction of a small
quantity of suboxide of copper, but in this case the colour is only
developed on reheating the glass. The more purplish tint given by a
somewhat similar treatment with gold was not known to the mediæval
glass-maker.[95] Manganese was of course the source of the purple—the
colour was used for flesh-tints in the twelfth century! The green was
made by a mixture of the _æs ustum_ or copper scale with a native oxide
of iron, the latter often known as _ferretto_—of this the best came
from Spain. Finally, the yellow was given either by the sesqui-oxide of
iron kept well oxidised by the presence of bin-oxide of manganese, or
(where the surroundings favoured a reducing action) by a mixture of
sulphur and some sooty material which probably yielded an alkaline
sulphide. But in the older glass the yellow colour was never very
brilliant; at a later time a fine yellow was obtained by a cementation
process from silver, which was applied as a chloride or a sulphide to
the surface of the glass.
If I trespass beyond my limits to give this rapid summary of what is
known of the colours of mediæval window-glass, it is because much of it
will be found applicable to the contemporary Oriental enamelled ware
and to the later Venetian glass.
In view of the high technical skill thus shown in the colouring and
working of the material, nothing is more remarkable than the almost
total absence from our collections of any glass, using that word in the
narrower sense, that we can classify as Gothic. We know, indeed, that
during these centuries much glass was made in France, Germany, and
Italy. But for one reason or another the material was not in favour for
objects that had any claim to be regarded as works of art. And yet
during all this time the few rare specimens of sculptured glass brought
from Constantinople, or of enamelled glass from Egypt and Damascus,
were highly prized, and it might well be thought that the skill and
knowledge to rival these examples were not wanting in the West. Such
was not the case, however; the monasteries had ceased to be centres of
practical art industry,[96] and the glass-makers had retired from the
towns to the depths of the forests, where under the patronage of the
local _seigneur_ they built their glass-houses, moving on from one spot
to another as the fuel became scarce.
On the condition of delivering yearly to their feudal lord a specified
number of vessels, these glass masters appear to have been freed from
further imposts, and indeed they soon began to claim special
privileges. In France some of these grants or contracts have been
preserved in local archives, and in them we have a source of
information lacking in other Western countries. Perhaps the most
significant of these patents is that granted in 1338 to a certain
Guionet. The Dauphin of the Viennois conceded to this _maître de
verrerie_ the right of taking wood when it suited him from parts of the
forest of Chamborant, on condition that the said Guionet should furnish
him yearly, for the use of the prince’s household, with the following
pieces of glass:—240 beakers with feet, known as _hanaps_; 144
_amphoræ_, 432 _urinalia_, 144 large basins, 72 plates, 72 plates
without borders, 144 pots, 144 water vessels, 60 _gottefles_, 12
salt-cellars, 240 lamps, 72 chandeliers, 12 large cups, 12 small
_barils_, 6 large vessels for transporting wine, and one _nef_. This
was certainly an ample yearly supply even for a princely household. The
practical, not to say homely, nature of most of the objects
requisitioned is obvious. The _gottefle_, we should add, has been
thought to correspond with the later German _gutraf_; it was in that
case a vase with a long twisted neck, sometimes double, like a Persian
sprinkler; it was perhaps used for oil.[97] The _nef_, no doubt, was an
imitation in glass of the well-known centre-pieces of silver in the
form of a ship. The little _baril_ is a form handed down from Roman
times. In Provence, as early as the year 1316, we find mention in the
inventory of the property of the Countess Mahaut D’Artois of ‘_Grant
planté de pots de voirre et de voirres d’Aubigny et de Provence et
d’autres païs et de diverses couleurs et bocaux et bariz_’ (Hartshorne,
p. 88).
We see by this how little ground there is for giving the credit of the
introduction of the manufacture of glass into France to King René. We
shall find, however, later on, that this great patron of the arts was
one of the earliest to take an interest in the Venetian glass of the
early renaissance, and to bring the Italian workmen into France.
The word _verre_, or in the earlier form _voirre_ or _vouarre_, was
used vaguely in France even in mediæval times for any cup from which
wine was drunk. This usage alone might be brought forward as a proof of
the general prevalence of glass vessels at an early time. Modern French
writers on glass cannot always escape the awkward expression ‘_un verre
de verre_.’ In England, where the use of the word glass in this sense
probably came in somewhat later, we find more than once in inventories
of the fourteenth century the quaint combination, ‘_un verre de
glass_.’ In France, however, the more frequent expression was ‘_un
verre de fougère_,’ literally ‘a glass of bracken,’ and we have here a
double metonymy. This association of bracken and glass may be
frequently noticed in the old French writers.
Long after the introduction of the _cristallo_ from Italy, there were
many in France who preferred to drink from the old greenish glass; like
the Germans of to-day, they declared that the wine tasted better. Even
Boileau, late in the seventeenth century, talks of a man holding ‘_un
verre de vin qui rit dans la fougère_.’
We see then what an important place bracken, _feucheria ad faciendum
vitrum_, played in the old glass-works of France. Now glass made from
fern-ashes must of necessity be of a very inferior quality, more so
probably than that made from the beechwood ashes used from of old in
Germany. The passage to the new methods would here be much more
revolutionary than in the case of the latter country. This
consideration may help to explain the fact that while the manufacture
of potash glass survived and adapted itself to the new methods in
Germany, it became in time quite extinct in France.
The chronicles and romances of the thirteenth, fourteenth, and
fifteenth centuries have been carefully searched by French scholars to
find references to glass. Some ambiguity arises from the vague use of
the word _verre_, to which I have already referred. But when Joinville
tells us how the Comte d’Eu, in a moment of expansion, ‘_dressait sa
bible le long de nostre table et nous brissoit nos pots et nos
vouerres_,’ we can probably accept the latter vessels as _verres de
verre_.
[Illustration:
_PLATE XX_
GERMAN LATE MEDIÆVAL GLASS
1. PRUNTED CUP FOR HOLDING RELICS 2. WAX COVER TO THE SAME, WITH SEAL]
In the royal inventories of the fourteenth and fifteenth centuries,
above all in those of Charles V. and of his brothers the Dukes of
Anjou, Berry, and Burgundy, where there is any mention of vessels of
glass, it is almost without exception of _verre de Damas_ or of _verre
à la façon de Damas_ that we hear. Quite an exception is the _goblet de
voirre blanc de Flandre, garny d’argent_, that we find in an inventory
of the possessions of Charles V., taken in 1379. Notwithstanding this,
it is evident that the French kings at this time took much interest in
the manufacture of glass. When hunting in the forests around Paris,
they would turn aside to visit the furnace of one of these local makers
of _verre de fougère_ who already claimed the privileges of gentlemen.
Thus early in the reign of Charles VI. we find an entry of a payment
‘_pour don fait par lui aux voirriers, près de la forest de Chevreuse,
où le roy estait alez veoir faire les voirres_.’ This was at the
beginning of the fifteenth century; later on, as we shall see, both
King René and Louis XI. were patrons of the glass-makers; and yet it is
doubtful if we have in our collections any examples of French glass
which can be attributed to as early a period as the reign even of the
latter king.
[Illustration:
_PLATE XXI_
GERMAN LATE MEDIÆVAL GLASS
1. CUP WITH PRUNTS 2. CUP WITH CONICAL COVER, FOR RELICS]
Of glass made in Germany before, say, the end of the fifteenth century,
we know even less than of the contemporary production in France.
Theophilus, it is true, tells us of the manufacture of sheets of glass
from cylindrical _manchons_, and this was probably until the
seventeenth century a specially German process; he describes, too, the
manufacture of blown glass of simple forms. But from his time, or at
least from the time of the pseudo-Heraclius a little later, to that of
Georg Agricola in the sixteenth century, when we find the glass
industry taking an important place in many parts of Germany, there is
little direct evidence on the subject to bring forward.[98] Apart,
however, from a few insignificant little bottles, used as reliquaries
(Plates XX. and XXI.), nothing survives from this time. On the other
hand, when in the fifteenth century we come again upon evidences of
contemporary glass in Germany and Holland, as above all in the pictures
of the early Netherlandish and of the Cologne schools, we find a
distinct form of goblet already established, the prototype, it would
seem, of a famous shape that was able to hold its own at the time of
the invasion of Italian glass in the sixteenth century. There is
nothing in France, still less in England, corresponding to the _römer_
and its various kindred forms.
In one application of glass the Germans appear early to have acquired
some skill. We may perhaps regard the thirteenth century as the time
when the use of glass for mirrors of any size first became general;
this may account for the frequent references to them in the literature
of the time. As far back as 1250, the great Dominican encyclopædist,
Vincent de Beauvais, states that the best mirrors are made from glass
and lead (_ex vitro et plumbo_). A _spiegel-glas_ is mentioned by a
German writer as early as the end of the twelfth century, and by the
end of the next century the mirror provided a frequent metaphor for the
poets of the time. Thus Dante, in two passages in the _Divina
Commedia_, speaks of ‘a leaded mirror.’ In the _Paradiso_ (ii. 89)
Beatrice declares that the rays of the sun are reflected from the moon—
‘_Come color torna per vetro
Lo qual diretro a sè piombo nasconde_’;
and in the twenty-third book of the _Inferno_ (25-26) Virgil says to
the poet, ‘_S’io fossi d’impiombato vetro_—I should not more quickly
receive your image than now my mind receives your thoughts.’ This
double reference would seem to point to a recent discovery that had
attracted Dante’s attention.
In the thirteenth and fourteenth centuries it would appear that
although the German mirror-makers had to import the clear crystalline
‘metal’ from Venice, the Venetians attempted in vain to make mirrors on
the German system. The difficulty, perhaps, was to prepare flat and
even sheets of glass of any size, and this difficulty the Germans may
have surmounted by means of the cylinder process described by
Theophilus.
The Nuremberg mirrors, however, so famous at a later time, were of a
different type. They were of spherical outline, cut directly from the
_paraison_ of the glass-blower; into this _paraison_ a mixture of
‘_piombo, stagno, marchesita d’argento e tartaro_’ had been introduced
before the vesicle was quite cool—so at least a contemporary Italian
writer asserts. Such mirrors were set in painted wooden frames with
broad margins. An example of one of these may perhaps be seen in Jan
van Eyck’s famous interior in the National Gallery.
If now we turn to England, the record is even more meagre. Mr.
Hartshorne, who has industriously brought together every reference he
could find to glass[99] in this country during the Middle Ages, is fain
to confess that he cannot point to a single example of what is
undoubtedly English glass made between the Norman Conquest and the time
of our Tudor kings. References to its use in contemporary writers are
much rarer than in France. The _cuppa vitrea_, which in 1244 Henry III.
sent to his goldsmith, Edward of Westminster, directing him to remove
the glass foot, to replace it by one of silver, and to mount the whole
in silver-gilt, was probably of Oriental origin; nor can we even claim
for certain as English the two humbler vessels belonging at a later
time to his son, Edward I.[100]
As to the three ‘verrers’ of Colchester who paid taxes about the year
1300, the distinction between _vitrier_ and _verrier_ does not seem to
have been as sharp then as it is now; they may well have been makers of
glass windows. It is more significant to find in Henry III.’s day a
Laurence Vitrearius holding land at Chiddingfold in Surrey, still in
the time of Elizabeth a centre for the manufacture of the native glass
made of fern-ash and sand. Again, William le Verir of the same place is
mentioned in a deed of 1301. But perhaps the strongest case is that of
John Glasewrythe of Staffordshire, who in 1380 had a grant of house and
land at Shuerwode, Kirdford,[101] and there made ‘brodeglass and
vessel’—that is to say, window-glass and hollow ware (Nesbitt, _South
Kensington Catalogue_, and Hartshorne, p. 132, etc.).
I reserve what I have to say of the mediæval glass of Italy—of the
early Altarists and Muranists—until I have described the enamelled
Saracenic glass which in some measure influenced it.
But before turning again to the East, I must not omit to mention
certain applications of glass that found favour in Western Europe
during the later Middle Ages; indeed, apart from the coloured windows,
such objects constitute the only _genre_ of glass that can distinctly
be classed as Gothic. I group together here various devices by means of
which a design or pattern was applied to the back of a small sheet of
glass—in gold for the most part, but other colours were sometimes
used. The plaque thus decorated was either fixed into a piece of
furniture, or simply backed with some impervious material. In this
somewhat indefinite group is included, on the one hand, what is in fact
a kind of thin mosaic; on the other, something that passed into the
variety of painted glass known in later times as _verre églomisé_. What
distinguishes all this class of decoration is that neither the colour
nor the backing is fixed by any furnace process—it is scarcely to be
regarded as an _art du feu_, and thus lies somewhat outside our subject.
Of the so-called Cosmati mosaics, where the little triangular pieces of
glass are inlaid in marble or wood, we have a good example in the
thirteenth-century shrine of the Confessor in Westminster Abbey. At the
same period a more elaborate means of decoration was obtained by
painting the backs of little plaques of glass with gold and colours,
and fixing them on the panels of pulpits, on the frames of the painted
reredos, or even on secular furniture. I have seen examples of church
furniture thus decorated at Aachen and in the Norman churches of
Southern Italy—a pulpit at Bitonto in Apulia is a remarkable example.
But we need not go far to find a still finer specimen of such work: the
Gothic framework of the _retabulum_ that formerly was placed in front
of the high altar in Westminster Abbey[102] is decorated with bosses of
glass paste cut or cast _en cabochon_, with casts of antique gems, and,
above all, with little plaques of blue and purple glass backed with
silver foil. On the upper surface of these glass plaques a design in
gold, consisting of small medallions with animals and twining branches,
stands out in low relief. The pattern, says Viollet-Le Duc
(_Dictionnaire du Mobilier français_, i. 338), was first painted on the
glass with a mixture of red ochre, wax and turpentine, and over this,
before it was dry, gold leaf was laid, the gold adhering only to the
soft ground. The effect of this external decoration is heightened by
the shadow which it throws upon the silver foil beneath.
In other examples, the pattern is painted in various colours under the
glass, and a leaf of gold, pasted beneath the more or less transparent
pigments, shows through here and there. In all these instances the
crude colour of the gold is lowered in places by coatings of varnish.
But plates of glass, somewhat similarly decorated, may play an even
more important part in the decoration of the backs of altars,
especially on the spandrels in the lower arcades of the reredos. The
decoration now becomes pictorial, and is often most carefully executed.
Or, again, such a little glass picture may be detached and mounted in a
frame to form a pax or _baiser-de-paix_, a _bijou_ reliquary, or other
small devotional object. In such cases the gold is applied to the back
of the glass by weak gum, and the design traced with a pointed
instrument somewhat in the manner of the catacomb glasses. The effect
may be heightened in various ways by additional touches of pigment on
the draperies, or by a glazing of colour for the flesh-tints; the
colours are worked up with a resinous body, and silver foil in little
plates and spangles is added in places; finally, over the back is laid
a piece of tinfoil, and this is folded over the edges (M. Alfred André,
quoted by M. Molinier, _Spitzer Catalogue_, vol. iii. p. 54). The back
of the plate is generally found to be protected by a kind of pitchy
varnish; to fix this some application of heat was doubtless necessary,
but in no case, I think, is the gold design in this late mediæval work
enclosed between pieces of glass which have been subsequently fused
together.[103]
We are here concerned only with the Gothic examples of this class of
work, and of these the majority appear to come from the north of
Italy—they are probably of Milanese or Venetian origin. There is often
in these early Italian plaques a coloured backing under the gold,
generally of a bright red, but sometimes of green or black, and this
backing shows through in places. In the case of a very beautiful
example formerly in the Spitzer collection, the design was drawn upon
the central portion of a plate of flashed glass; although this
medallion is only 5-1/2 inches in diameter, there is a distinct boss in
the centre. That such a defective piece should have been chosen for
this delicate work would go to prove the rarity of sheets of glass with
even surface at this time.
In later days more colour was used in the decoration, but such work as
the magnificent _baiser-de-paix_ in the Louvre, which came from the
chapel of the order of the St. Esprit, does not fall within our present
limit of time.
The late Marquis Emanuele D’Azeglio devoted himself to collecting
specimens of gilt and painted glass of all ages and countries. This
collection, unique of its kind, he bequeathed to his native town of
Turin, where it is now exhibited in the Museo Civico. In some of the
earlier pieces, especially on one of Byzantine character—perhaps
Muranese work of the end of the thirteenth century—the gold is laid
down upon glass of very irregular thickness. There are a few examples
of Gothic work of this character in the British Museum, at South
Kensington, and in the collection of Mr. Salting.