ENGLISH GLASS OF THE SIXTEENTH AND SEVENTEENTH CENTURIES
In an English work treating of glass, or rather of certain descriptions
of glass, and that chiefly from the artistic point of view, what
position in the book and what relative amount of space should be given
to the glass of England?
The position is, indeed, readily defined, for our country has but
slight claims to recognition as a producer of artistic glass until the
commencement of the eighteenth century—indeed we may perhaps say until
that century was well advanced. The consideration, then, of the glass
of this country must be kept back until that of all the other European
States—Italy, France, Spain, Germany, and the Netherlands—that have
at one time or another produced glass of artistic importance has been
dealt with.
As to the relative importance of our English glass and the amount of
space to be allotted to it, this is a question difficult to answer. For
a moment, no doubt, towards the end of the eighteenth century, it held
the premier place in Europe, on the ground, above all, of the
excellence of the material. Advantage was taken of certain exceptional
qualities in the English flint or lead glass to produce a deeply cut,
facetted ware, solid and brilliant, something undoubtedly _sui generis_
and suitable to its place on the sideboard, or on the well-polished
mahogany table when the cloth was removed. The flashing fire of the
lights cast back from the skilfully arranged facets of the decanters
and glasses, combined with the softer reflections from the silver plate
to give an undeniable charm and an individual stamp to these late
Georgian dinner-tables. This play of lights has appealed to, and has
been not unsuccessfully reproduced by, more than one painter of the
present day. But this facetted ware, the one glory of our English
glass, came late into vogue, at a time when the prevailing fashions
allowed little room for any freedom of treatment, so that it is only
rarely that we can find any merit in the forms and decorations of
individual examples.
It is, however, to a somewhat earlier period that the modern enthusiast
turns. His interest lies in the air-twisted stems, the folded feet, and
the bell-shaped bowls of the drinking-glasses of the eighteenth
century. Now these, though made of flint glass, belong mostly to a time
before full advantage had been taken of the dispersive power of that
material upon the rays of light. Here the question may well be
asked—putting aside all matter of historical or sentimental
interest—what can we say of these endless rows of glasses, classified
and sub-classified on the ground of variety of stem or bowl, as
_objects of art_? But this is a point upon which I should prefer not to
deliver a definite judgment; I have said enough to indicate my personal
standpoint. I can only refer the reader to the copiously illustrated
work of Mr. Hartshorne on English glass, of which the larger part is
occupied with this branch of the subject.[228]
It may be said that the history of English glass divides itself into
two periods. For the first we have abundant documentary
evidence—patents for new processes and petitions for or against these
patents, to say nothing of notices in contemporary journals and
memoirs—but against this an almost total absence of examples of the
glass actually made. This period extends from the early days of
Elizabeth almost to the end of the seventeenth century. In the second
period, on the other hand—and this includes nearly the whole of the
eighteenth century—the documentary evidence almost completely fails
us; but in its place a fairly rich material harvest is available—the
wine-glass, above all, so dear to the collector, now asserts itself.
When at the beginning of the reign of Elizabeth, or even a little
earlier, a few rays of light begin to be thrown upon the glass made in
England, we find the industry centred in a district on the borders of
Surrey and Sussex: we are here at the western extremity of the great
forest of the Weald, that was a little later to become for a time the
home of an important iron industry. Here the raw materials and the fuel
were at hand. Fuel from the oaks and beeches, and from trees of smaller
growth; the silica from the ‘Hastings sands,’ selected from spots where
the beds were tolerably free from iron; and finally the alkali, for the
most part from the ashes of the bracken that then as now grew so
abundantly in the glades of the woods. For this old English glass, like
that of France, was essentially a _verre à fougère_,[229] made in
districts remote from towns. At a somewhat later time the glass-workers
were indeed forbidden to set up their furnaces within twenty-two miles
of London, seven miles of Guildford, or within four miles ‘of the foot
of the hills called the Sussex downs.’
The little village of Chiddingfold, just within the boundary of Surrey,
may perhaps lay claim to be the original ‘metropolis of English glass,’
and a line measured from Hindhead to Petworth passes close to the
various places—Loxwood, Kirdford, Fernfold, Wisboro’ Green—where we
know that furnaces were already established early in the sixteenth
century. I have already referred to this district when speaking of the
English glass of mediæval times (see p. 139). Fragments of green glass
have been found on the site of a glass-house at Chiddingfold. In the
Museum at Lewes are two bulbous flasks with long necks of this green
Weald-glass. There was another centre of the glass industry in East
Sussex, in the country to the north of Hastings. In a mediæval document
concerning Beckley, in this district, the name Glassye Borough occurs.
At these woodland glass-houses, for many generations, the wandering
pedlars, the ‘glass-men,’ had been wont to renew the stock of
‘vrynells, bottles, bowles, cuppis to drinck and such lyke,’ that they
hawked along the country-side. You may send, says Thomas Charnock in
his _Breviary of Philosophy_ (1557), to Chiddingfold, to the
‘glassemaker,’
‘And desire him in most humble wise
To blow thee a glass after thy devise.’
That is to say, that the glass-blower, as we have seen in other cases,
worked from the patterns provided by his customers.
Camden says of the Sussex glass that in his time it was only used ‘of
the common sort.’ Possibly the Sussex glass-blowers made quarrels and
bull’s-eyes for windows also;[230] this, however, was an industry that
centred rather in London, especially in Southwark. Now it was above all
the demand for larger and better made panes for use in the new mansions
with spacious windows—the ‘glass houses’ of the proverb about throwing
stones—that were now springing up on every side, that gave the most
powerful impulse to the introduction of the newer methods of working
glass that had already taken root in France and in the Low Countries.
It must be remembered that in the preparation of the stained glass for
church windows large pieces were not required. Considerable artistic
skill in this branch would be quite compatible with a very primitive
method of blowing and ‘flashing’ the glass. At this time the new
industry—the making of large sheets of broad-glass, that is to
say—was centred in Lorraine, in the country stretching from the Vosges
to the Ardennes; in a lesser degree in Normandy. It is uncertain in
what the superiority of the ‘_verre en tables quarrées_’ made by the
Lorrainers consisted; there is no positive proof that they had as yet
adopted the German cylinder process (see pp. 129 and 234 _note_),
though this is in every way probable.
The French glass-workers who came to England belonged, for the most
part, to the old noble families. We find in our English documents some
of the very names—Hennezel, for instance—that occur in the famous
_Charte des verriers_ granted by John of Calabria, son of King René, in
the year 1448 (see p. 230).[231] When these foreigners are mentioned in
our English documents they are invariably described as gentlemen or
esquires.
We must remember that in the sixteenth century Antwerp held a
commercial position something like that taken later by Amsterdam and
London: the town was, above all, the centre of the glass trade. It is
not surprising then to find that it was through the medium of an
Antwerp merchant, one Jean Carré, that the French glass-makers were now
introduced into England.[232] Carré, in association with a certain
Briot, brought over both Normans and Lorrainers, and the quarrels and
disputes that soon broke out appear to have had their origin in the
fact that the men to whom the first patents were granted were not
practical workers themselves, and that they were therefore dependent on
others.[233] In any case, before the year 1570, gentlemen of Lorraine
bearing the well-known names of Hennezel, Du Thisac, and Le Houx, as
well, probably, as representatives of the Le Vaillant and other Norman
families, were making glass in more than one spot in the Weald as well
as in London.
But these proud, hot-headed foreigners do not seem to have been popular
in Sussex. There were frequent petitions against the destruction of the
woods to supply the fuel for their glass-houses, and we hear of an
attempt made to rob the ‘outlandish men’ that made glass near Petworth
and to burn their houses. Before 1576, then, the Lorrainers were
already in search of forests where they could work without hindrance;
they began that long peregrination that took them by way of the
Hampshire woods to the Forest of Dean, and finally to Stourbridge and
Newcastle.[234]
Some remains of a glass-house at Buckholt Wood, on the line of the old
Roman road between Salisbury and Winchester, had long attracted the
attention of antiquaries before a satisfactory explanation of their
origin could be found. Large quantities of broken window-glass, as well
as fragments of glass of many other kinds, including some of distinctly
Venetian type, had at times been dug up. These remains, doubtless,
represent a store of ‘cullet’ or old broken glass destined to be
remelted, and therefore not necessarily all of it made on the spot.
Fragments, too, of the glass-pots were found, of a greyish-white clay
not of local origin. It is only quite recently that with these
discoveries have been associated certain entries in the registries of
the Walloon Church at Southampton (these were published a few years ago
by the Huguenot Society). Among those admitted to the Lord’s Supper, in
the years 1576 to 1579, we find the names of members of the Du Thisac,
Hennezel, and Le Houx families, all Lorrainers, as well as that of
Pierre Vaillant, a Norman. These communicants are described in the
registry as ‘_Ouvriers de verre a la verriere de boute haut_’
(elsewhere spelt _Bocquehaut_), a fairly good French rendering of the
word Buckholt. It is not every day that one comes across so neat and
conclusive an instance of documentary research supplementing and
completing the work of the ‘men of the spade.’
But here again, in spite of the attraction of the not far distant
Walloon Church, the Lorrainers made but a short stay. In 1599 one
‘Abraham Tysack, son of a frenchman at the glasse-house,’ was baptized
at Newent, in the Forest of Dean, where, at any rate, there can have
been no deficiency of fuel. But the wanderers made apparently no long
stay in the district, for we find that some at least of the number
after a few years settled at Stourbridge, in Worcestershire. The famous
clay of this district, still unsurpassed as a material for the
glass-pots, was, it would seem, already worked along with the beds of
coal which this clay underlies. Here, at King’s Swinford, in 1612, the
name of Tyzack occurs in local records, and a little later, at Old
Swinford, those of Henzey and Tittery. In this neighbourhood some
members of these families at length settled down, maintaining close
relations with certain of their relatives who pushed on as far as
Newcastle-on-Tyne. At this last town, in 1617, a Henzey was fain to
enter the service of Sir Robert Mansell, who was already bringing the
principal glass-workers of England within the net of his monopoly.
I have dwelt on the wanderings of these Lorrainers, who were above all
makers of window-glass, as to them rather than to the Venetians is due,
I think, the definite establishment of a glass industry in England. For
it must be borne in mind that the principal stimulus came from the
demand for better and larger panes for the windows of the new
renaissance houses,—somewhat later, perhaps, for the windows of
‘glass-coaches’ also.
Already early in the sixteenth century not a few examples of Venetian
and, perhaps, even of Oriental glass, may have found their way into the
houses of the wealthy. But we must regard as quite exceptional—the
result, probably, of some passing whim of the king—the collection of
371 pieces of glass that were in 1542 in the possession of Henry VIII.
These are described under the head of ‘Glasses and sundry other things
of erthe’ in an inventory of certain valuable effects in the Palace at
Westminster (_Archæological Journal_, vol. xviii., 1861). Among them
there is mention of flagons, basins, ewers, standing-cups, cruses,
layers, spice-plates, and even forks and spoons of glass. Many of these
pieces are described as ‘jasper-colour’—these were probably of a kind
of _schmelz_—and there is frequent reference in the list to ‘blue
glass’ and ‘glass of many colours.’ A ‘layer’ with the initials ‘H and
A engraven on the cover,’ as well as a cup with ‘Quene Annes sipher
engraven on it,’ had doubtless belonged to Anne Boleyn. The following
items are of some interest:—
‘One thicke glasse of christall with a case of lether lined with
crymson vellat.’
‘Three aulter Candlestickes of glasse.’
‘Oone Holly-water stocke of glasse with a bayle.’
‘Twelve bottles of glasse with oone cover to them all wrought with
diaper work white.’ By this last expression are we to understand some
kind of _vetro di trina_?
Finally, ‘One rounde Loking Glass sett in a frame of wood, vj cornered,
painted under glass with the armes of Ingland, Spayne, and Castile’
carries us back to the days when Catherine of Aragon was queen. Of this
method of decorating the frames of mirrors with inlay of glass painted
on the inner surface I have already spoken. I would again refer the
reader to the mirror in the Arnolfini Van Eyck at the National
Gallery.[235]
The earliest notice that we have of Venetian glass-workers in England
carries us back to the year 1550, and it takes a form that is
characteristic of the times. This is a petition to the Council of Ten,
that has been found among the Venetian state papers. It is signed by no
less than eight Muranese glass-workers, imprisoned in the Tower of
London: they declare that they are threatened with the gibbet if they
fail to work out their contract. These poor men were indeed between the
devil and the deep sea; for did they delay their return to their homes
they were liable, by a newly issued edict, to a long term in the
Venetian galleys. It was only by the personal intervention of the young
king that some arrangement was finally made that allowed of these
Muranese glass-workers returning unmolested after working off part of
their contract. One of these men indeed elected to remain behind, but
he before long made his way to the Low Countries, and this first influx
of Venetian workmen seems to have led to little as far as English glass
was concerned.
Cornelius de Lannoy, from whom Cecil hoped so much, was perhaps as much
an alchemist and a universal schemer as a worker in glass. He was set
to work at Somerset House in 1564, but with little result, it would
seem. He attributed his failure to the clumsiness of the English
workmen and to the want of a suitable clay for his glass-pots.
It is to Jacopo Verzelini, a man evidently of some energy and resource,
that we must give the credit of first successfully making the Venetian
_cristallo_ in England. When in 1575 he obtained a patent ‘for the
makinge of all manner of counterfayt Venyse drinkinge glasses’ (but
not, it would appear, of glass for windows), he was already established
in London. Stow, writing a little later, says: ‘The first making of
Venise glasses in England began at the Crotchet Friars, about the
beginning of the reign of Q. Elizabeth, by one Jacob Vessaline an
Italian.’ The Friars Hall, he tells us, ‘was made a glasse-house,
wherein was made glasse of divers sorts to drincken.’ It was in this
same hall probably that the unhappy craftsmen of Edward VI.’s time had
been set to work. Verzelini, like other glass-workers of the period,
reached England, it appears, by way of Antwerp. At any rate he was
married to a lady of that town, of good family, who bore him twelve
children. This we know from the monumental brass to his memory that may
still be seen in the little church of Down in Kent, where in the year
1606 he was buried.
We see, then, that before the death of Elizabeth the making of both
hollow ware and window-glass by the new methods was firmly established
in London and in the provinces. Great complaints had already arisen of
‘the making of glass by strangers and outlandish men,’ and we hear of
‘the timber and woods spoiled by the glass-houses.’[236] The same
difficulty arose as in France. It was argued that the foreigner should
be required to take native apprentices. But there is evidence that as
late as the first quarter of the seventeenth century, the making of the
better kinds of glass, the ‘Christalline Morana Glass,’ was still in
the hands of Italians. This we have seen was for long the case in
France as well. But we in England were in a measure dependent upon the
foreigner for our window-glass also, this time upon the Lorrainer.
Of glass made in England during Elizabeth’s reign I can point to a
goblet now in the British Museum. It is dated 1586, and bears an
inscription in capitals of somewhat Gothic character—IN : GOD : IS :
AL : MI : TRUST. The glass is engraved with the diamond, and is
decorated with stringings of white enamel.[237] The plain cylindrical
glass tankard in the Gold Room is remarkable only for the silver-gilt
mounting and for the arms of Cecil on the cover.[238]
We have seen that early in the seventeenth century the French
_gentilshommes de verre_ were firmly established at Stourbridge and at
Newcastle. Now by this time the outcry against the destruction of our
English forests, the source of the timber for the navy, was becoming
general. It was directed against the iron-smelters in the first place,
and then against the makers of glass, above all against foreigners. ‘It
were the less evil,’ says a proclamation of 1615, ‘to reduce the times
into the ancient manner of drinking in stone and of lattice windows
than to suffer the loss of such a treasure.’ It was in the Stourbridge
district that Bub Dudley[239] and others were occupied at this very
time with the problem of smelting iron by means of pit-coal. With them
was probably associated Thomas Percivall, to whom more than to any one
else is to be given the credit of the first successful employment of
coal in the glass-furnace.
Others were working on the same lines. To Sir William Slingsby and his
associates a licence was issued in 1610, but this was a very general
document, vaguely worded. More precise was the patent granted the next
year to Sir Edward Zouche, Thomas Percivall, and others. It was under
this patent that the process was perfected, probably at the glass-house
at Lambeth, under the charge of Percivall. Only a few years later, in
1616, English coal was brought into use at the glass-works of St.
Sever, near Rouen, very likely through the mediation of one of the
Norman glass-workers settled in England.
There were many difficulties to be overcome before this pit-coal could
be used with success. Greater care had to be taken in the selection of
the materials for the pots—perhaps without the Stourbridge clay
success would not have been attained—and it was found to be necessary
to ‘close the pots,’ that is to say, to use a covered crucible so as to
protect the glass from the smoky, sulphurous gases given off by the
coal. The credit of the invention of these closed pots, with the mouth
at the side facing the opening of the furnace, is also to be given to
Percivall.
I dwell on these practical details for a special reason. In the first
place, the use of coal and the consequent change in the form of the
crucibles mark the beginning of English glass as a distinct _genre_.
Again, this change is closely connected with a further and still more
important step—the use of lead as an essential constituent in a new
kind of ‘metal,’ the famous English flint-glass of later days. It is
these two novelties that form our contribution to the technique of
glass-making. Not that I can find any proof that lead-glass was made in
England at so early a date. But on the one hand the use of a covered
pot rendered it more difficult, at that time at least, thoroughly to
melt the contents, and therefore favoured the use of a more fusible
mixture; on the other, in the case of a glass containing lead, it is
above all essential to protect the ‘metal’ from the fire.
The history of the progress of glass-making in England from the early
days of Elizabeth to the outbreak of the Civil War in the next century,
is chiefly concerned with the licences and patents granted to a
succession of English and foreign ‘adventurers.’[240] No doubt there
were many abuses in this system; but it is impossible to overlook the
fact that the Cecils and the other advisers of the Queen were enabled
by such means to encourage the foundation of many industries, and this
chiefly by the help of foreigners. For at the beginning of Elizabeth’s
reign we had fallen sadly behind in the matter of the industrial arts.
Not only France and Italy, but Germany too and the Netherlands, had
much to teach us.
Already, however, before the death of the Queen and still more in the
next reign, there arose, as I have said, a great popular outcry against
the monopolists, and this feeling of indignation found an echo in more
than one of James’s parliaments. It is the more strange, therefore, to
find that it was during this reign that the whole glass industry of the
country fell for the first and last time into the hands of one man. But
this was no other than Sir Robert Mansell, Admiral of the Fleet, a man
of exceptional energy and a born fighter, one who had in early life had
more than one brush with the Spaniards. King James, when approached on
the subject of Mansell’s glass monopoly, marvelled that ‘Robin Mansell
being a seaman, whereby he hath got so much honour, should fall from
water to tamper with fire.’
The first we hear of Mansell in this connection is in the year 1615,
when we find him associated with Sir Edward Zouche, Thelwell,
Percivall, and others in a patent for making glass with sea-coal. But
before this he had probably for some time been interested in certain
London glass-works. And now before two years had elapsed he had bought
out all his partners[241] and commenced his reign as ‘glass-king.’ This
monopoly, in spite of frequently renewed opposition, Mansell succeeded
in maintaining up to the time of his death in the days of the
Protectorate. He hunted down the local glass-houses where wood, now
forbidden by law, was still employed. He granted licences to some of
the Lorrainers working at Stourbridge and elsewhere, while—as at
Newcastle, where he had glass-works under his direct management—he
took others of these foreigners into his employ. In London, on the
other hand, at the glass-furnaces of Winchester House, which he now
took over, Sir Robert employed Italians.
We here come into contact with another and not less interesting man,
James Howell, like his master Mansell, a Welshman.[242] Howell was in
1618 ‘steward of the glasse-house’ in Southwark, but he was glad to
change this position for that of traveller for Mansell in Spain and
Italy; for, so he writes to his father, ‘I should in a short time have
melted away to nothing among these hot Venetians.’ His duties were now
to obtain workmen from Italy, and the raw materials, especially the
‘barillia,’ from Spain. In the following year he brought over one of
the famous Miotti family from Middelburg, and not long afterwards we
find him writing from Alicante an interesting account of the ‘Barillia,
a strange kind of vegetable that grows nowhere upon the surface of the
Earth, in that perfection as here.’ ‘The Venetians have it hence,’ he
continues, and he proceeds to give a detailed account of the method of
preparation (Book I. section I. xxv.). Howell’s letters from Venice are
most interesting, and have provided many ‘elegant extracts’ for later
writers. For instance, there is a passage in which he speaks of ‘lasses
and glasses,’ and of the brittleness that beauty shares with the
mirrors of Venice[243]—the rest of the passage is, however, rather too
outspoken for our present taste.
The contention between Mansell and the anti-monopolists was above all
warm about the year 1623, on the occasion of the renewal of his patent
for another fifteen years, and the ‘New Patent,’ the ‘Reasons against
the same,’ Mansell’s ‘Defence’ and his ‘Motives and Reasons,’ and
finally the ‘Answer’ to this last, followed in quick succession. All
these documents and pamphlets are reproduced by Mr. Hartshorne; they
form indeed an important source of information for the history of
English glass. From them we learn that Mansell, after many failures
elsewhere and the expenditure of many thousand pounds, first at
Newcastle successfully made window-glass with the native coal; that the
clay for the pots was at the commencement brought from Staffordshire,
but that as the English clay proved unsatisfactory, he obtained a
better material at infinite cost ‘from beyond Roan in France,’ and
finally from ‘Spawe in Germany.’ At the time he was writing he indeed
protests that he had already sunk £24,000 in his ventures.
The precise position of Mansell after the expiration in 1638 of the
second term of his patent is somewhat obscure, but he seems to have
steered well among the troubles of the time and to have maintained his
monopoly. At the period in question, he tells us he was producing
‘Ordinary Drinking Glasses’ for wine and for beer at four shillings and
half a crown a dozen respectively, as well as mortar-glasses[244] at
one-and-fourpence a dozen. He was at the same time making beer and wine
glasses of crystal (these were from two to three times as dear as the
last), beside looking-glasses and spectacle-glass plates in rivalry
with the Venetians; finally, with English materials, window-glass and
‘green-glasses.’
There is nothing in all this, or indeed in any of these patents and
petitions, to point to the existence of lead-glass at this time. The
use of barilla, I may add, is incompatible with the preparation of a
lead-glass; in such a glass it is essential that the alkali should be
potash. On the whole, during the long period of the Mansell monopoly
(from 1615 to, say, 1655) little progress appears to have been made in
the manufacture of glass, but of course we must make allowance for the
times of civil strife that filled the latter part of this period.
After the Restoration the issue of patents began again. Everything
points at this time to a renewal of interest in Venetian glass. When,
however, in 1663 the Duke of Buckingham obtained his licence, his claim
was based upon the improvements he had made in the looking-glass plates
and in the plates for the glass-coaches. As in France, sheets of large
size and good material were now in demand for both purposes. It was
somewhat later, it would seem, that he turned his attention to making
hollow ware in the Venetian fashion. Although nitre, a salt of
potash,[245] played an important part in the glass made by the duke,
there is no proof that any use was made of red lead or of litharge.
Evelyn, who in 1673 visited the duke’s ‘Italian glass-house at
Greenwich where glasse was blown of finer metal than that of Murano at
Venice,’ says nothing about such substances being employed.
But in spite of this progress in the home industry, the importation of
chests of glass from Venice was at its height in the reign of Charles
II. This we see from the correspondence of a London glass merchant, one
John Greene (1667-1672), with a Venetian firm, which has fortunately
been preserved.[246] Along with these letters were found the ‘office
copies’ of the patterns which Greene sent out to Venice as a guide to
the glass-blowers. Here we have mention of ‘clouded calsedonia glasses’
for beer, claret, and sack, ‘creuits with or without feet, brandj
tumblers,’ and ‘glasse floure potts.’ Not the least interesting item is
the ‘Rhenish wine glasse,’ which is illustrated by a typical roemer
with prunts on the stem, almost our only evidence of the use of these
goblets in England. Greene advises his Venetian correspondent that the
looking-glasses and the coach-glasses are to be packed at the bottom of
the cases to escape if possible the search of the custom-house
officials. What especially strikes one in examining the patterns of the
drinking-glasses, which form the bulk of the orders (Hartshorne, Plates
30-32), is the fact that the stem or shank, so important a part of the
eighteenth-century glass, is not yet developed; the conical bowl is
separated from the foot by a simple or fluted bulb, or sometimes by two
such bulbs or knops.
But this Venetian trade had now seen its best days; there are some
hints of a falling off in Greene’s last two letters (1671-1672). On the
other hand, during all this period the enterprising glass firms of the
Netherlands kept up a close intercourse with England. As early as 1662
a patent for making various kinds of glass was obtained by one John
Colenet, whom Mr. Hartshorne has very plausibly claimed as a member of
the great glass-making family of Ghent and Namur, the De Colnets, so
often mentioned in the letters of M. Schuermans. A few years later the
tables were turned, for now the De Colnet firm was fain to engage an
Englishman to produce ‘_verre à l’Angleterre_.’ In 1680 the great rival
firm of Liége, the De Bonhommes, according to a document quoted by M.
Schuermans (Letter vii.), was already making ‘_flint-glass à
l’Anglaise_.’
Now this statement brings me face to face with what is the great crux
in the history of English glass—the question, namely, when and where
lead-glass was first applied to the manufacture of hollow ware.
But first I must say a word of a little book published in 1662. This is
the already-mentioned translation by Christopher Merret of the _Arte
Vetraria_ of Antonio Neri (see p. 7). Merret, who was a man well
abreast of the science of his day and an early, if not an original,
member of the newly founded Royal Society, has supplemented Neri’s
series of recipes with certain ‘Observations’ of his own. Here may be
found some curious information concerning the materials used in the
manufacture of the _cristallo_, for it is with this glass that the
author is chiefly concerned. Merret does not appear to have had much
acquaintance with the glass made in England in his day. For the
practical details of the furnace and for the processes of glass-blowing
he takes us back to Agricola. Both Neri and his translator are indeed
for the most part occupied with the nature and preparation of the
materials, and with the various methods by which glass may be
coloured.[247] Neri, like all the old writers, knew of the merits of
lead-glass in the preparation of pastes for the manufacture of
artificial gems; in his sixty-first section he tells us: ‘Glass of
lead, known to few in this art, as to colour is the finest and noblest
glass at this day made in the furnace. For in this glass the colours
imitate the Oriental gems, which cannot be done in crystal. But unless
diligence be used all sorts of pots will be broken, and the metal will
run into the furnace.’ Upon this passage Merret observes: ‘Glass of
Lead! ’Tis a thing unpractised in our furnaces, and the reason is
because of the exceeding brittleness thereof.’ Lead, he continues, is
indeed the principal ingredient in the glaze of the potter, ‘and could
this glass be made as tough as Crystalline, ’twould far surpass it in
the glory and beauty of its colours.’ Thus we see, with Merret as with
Neri, the great merit of lead-glass is the capacity possessed by it of
bringing out the colours of metallic oxides. They still regard the
material from the mediæval point of view. The bad working qualities of
this glass of which Merret complains may very probably have been due to
the fact that, starting from the basis of their _cristallo_, the
glass-workers continued to use the soda-holding barilla instead of
employing a potash salt.
The Venetians in the preparation of their _cristallo_ laid great stress
on the hard white pebbles, the _cogoli_, from the bed of the Po or of
the Ticino; these they regarded as an essential constituent of a good
glass. We in England, during the reign of Charles II., succeeded in
replacing these pebbles by our native flints; and this English
flint-glass,[248] properly so-called, early acquired a good reputation
on the Continent. The ingenious Mr. John Houghton, writing in 1683
(_Letters for the Improvement of Husbandry and Trade_), after speaking
of our dependence upon the Venetians some years since, goes on to say:
‘Now by the fashion of using glasses in coaches and other good means we
easily enough serve our neighbours.’ In 1682 he tells us there were
exported from England two thousand five hundred and seventy-two
drinking-glasses, besides some looking-glasses and ‘window chests.’
This confirms what I have said of the date when English flint-glass
became well known in the Low Countries. Now it is generally taken for
granted that by this time the term flint-glass had come to mean
lead-glass. Certainly soon after the beginning of the next century
lead-glass was already recognised as essentially a substance of English
origin; but, as I have said, there is unfortunately not a word of
evidence, documentary or otherwise, to show when or where this glass
was first made, nor is it possible, I think, to point to any example of
this lead-glass to which an earlier date than the first or second
decade of the eighteenth century can be attributed. Indeed everything
points to the English flint-glass of the last quarter of the
seventeenth century being a form of the Venetian _cristallo_.
In any case it is essential to bear in mind that both in chemical
composition and in physical properties no two things could be more
unlike than the _cristallo_ on which the early flint-glass, properly so
called, was founded, and the lead-glass which afterwards usurped the
name.[249] The one is a typical soda-lime, the other an equally
definite potash-lead glass, and the materials had to be sought for from
entirely different sources.
The above-mentioned Mr. John Houghton, who every week, in the
commercial paper edited by him, published an article on some technical
or scientific subject, in the spring of 1696 devoted a series of these
‘leaders’ to the subject of glass. After some general reflections on
the substance, when we are told, among other things, that
‘Vitrification is the last mutation of bodies of which Nature is
capable and from which there is no going back,’ in his issue of May 2
he takes up the main subject. ‘According to my information,’ he tells
us, ‘we are of late greatly improved in the art of _Glass-making_. For
I remember the time when the Duke of _Buckingham_ first encouraged
_glass-plates_, and _Mr. Ravenscroft_ first made _Flint-glass_.[250]
Since then we have mended our Window-glass and outdo all abroad. And
what e’er may be said against _Stock-Jobbery_, yet it has been the
Means to raise great Summs of Money to improve this Art.’ Again, on May
16 we are given a carefully classified list of ninety glass-houses
existing in England. Of these, twenty-four were in London, nine at
Bristol, seventeen at Stourbridge, and eleven at Newcastle. These
glass-houses he divides into those for looking-glass plates, for
bottles and for ‘_Flint, Green, and Ordinary_.’ Now the rational
inference from all this seems to me to be that Houghton, _who was in a
position to know_, knew nothing about lead-glass. The flint-glass
houses are classed together with the ‘green’ and ‘ordinary,’ and
flint-glass for him was glass made from flints.
So, as we have seen, Haudicquer de Blancourt, writing in France a few
years earlier, knew nothing of lead-glass other than that used for
objects of _verroterie_. It is at least evident that if our own
glass-makers had mastered the art before the end of the century, the
secret was well kept.[251]
But before proceeding further, it may be well to form some definite
idea of the composition of lead-glass and of the physical properties
that led to its replacing in great measure the soda-lime glass of
Venetian type. In the first place, as I have said, it is essential that
the alkali in this glass (in the manufacture of hollow ware, at least)
should be potash, and it was, perhaps, the fact that the lead was at
first used along with soda that so long delayed the production of a
‘metal’ suitable for the manufacture of blown-glass. Again, the potash
in the case of lead-glass must be something quite different from the
impure material employed for the old green glass; this crude alkali
contained, among other bases, a large percentage of lime. Saltpetre
appears to have been used in the first place, and then a more carefully
lixiviated form of vegetable ashes known as pearl-ash. The amount of
lead oxide may vary from 28 to 40 per cent., and the specific gravity
of the resultant glass from 2·8 to 3·6.
The great merit of lead-glass lies in its absolute transparency and
brilliancy, combined with a certain darkness in the shadows. This
brilliancy and fire, it is well to point out, are only indirectly
dependent upon the refractive power exercised by the glass upon the
rays of light that pass through it; in this respect lead-glass differs
little from rock crystal or from the Venetian _cristallo_. But one
quality it has which distinguishes it from all other kinds of glass as
well as from nearly all transparent natural stones, the diamond, of
course, excepted. This is the power possessed by it of _dispersing_ the
rays of white light: the elements of which this light is composed in
passing through lead-glass are bent aside in _different degrees_, so
that the issuing ray is broken up into its component colours. This it
is that gives fire, but this fire is only fully brought out by means of
facetted or angular surfaces. On this point—the distinction between
refraction and dispersion—a good deal of confusion exists. The
following table, which I borrow from a little book on gems by Professor
Church, may help to clear up this point:—
Refractive Index. Comparative Dispersing
Power.
Diamond, 2·75 44
Flint-glass, 1·57 36
Rock-crystal, 1·55 14
Plate and crown glass, 1·52 15
We here see that lead-glass or flint-glass has little greater
refractive power on light than rock crystal or the ordinary plate and
crown glass of commerce which belongs to the same family as the
_cristallo_ of the Venetians. In dispersive power, on the other hand,
it stands apart from both these substances and rivals the diamond in
scattering the component rays of white light.