Glass has properties peculiarly its own; one of which is that it is of
no greater bulk when hot, or in the melted state, than when cold. Some
writers state that it is (contrary to the analogy of all other metals)
of greater bulk when cold than when hot.
It is transparent in itself; but the materials of which it is composed
are opaque. It is not malleable, but in ductility ranks next to gold.
Its flexibility, also, is so great that when hot it can be drawn out,
like elastic thread, miles in length, in a moment, and to a minuteness
equal to that of the silk-worm. Brittle, also, to a proverb, it is so
elastic that it can be blown to a gauze-like thinness, so as easily to
float upon the air. Its elasticity is also shown by the fact that a
globe, hermetically sealed, if dropped upon a polished anvil, will
recoil two thirds the distance of its fall, and remain entire until the
second or third rebound. (The force with which solid balls strike each
other may be estimated at ten, and the reaction, by reason of the
elastic property, at nine.) Vessels, called bursting-glasses, are made
of sufficient strength to be drawn about a floor; a bullet may be
dropped into one without fracture of the glass; even the stroke of a
mallet sufficiently heavy to drive a nail has failed to break such
glasses. In a word, ordinary blows fail to produce an impression upon
articles of this kind. If, however, a piece of flint, cornelian,
diamond, or other hard stone, fall into one of these glasses, or be
shaken therein a few moments, the vessel will fly into a myriad of
pieces.
Glass of the class called Prince Rupert Drops exhibits another striking
property. Let the small point be broken, and the whole flies with a
shock into powder. Writers have endeavored to solve the philosophy of
this phenomenon; some by attributing it to percussion putting in motion
some subtle fluid with which the essential substance of glass is
permeated, and thus the attraction of cohesion being overcome. Some
denominate the fluid electricity, and assert that it exists in glass in
great quantities, and is capable of breaking glass when well annealed.
These writers do not appear to have formed any conclusion satisfactory
to themselves, and fail to afford any well-defined solution to the
mystery.
Another phenomenon in connection with glass tubes is recorded in the
"Philosophical Transactions," No. 476:--
"Place a tube, say two feet long, before a fire, in a horizontal
position, having the position properly supported, say by putting in a
cork at each end supported by pins for an axis; the rod will acquire a
rotary motion round the axis, and also a progressive motion towards the
fire, even if the supporters are declined from the fire. When the
progressive motion of the tube towards the fire is stopped by any
obstacle, the rotation is still continued. When the tubes are placed in
nearly an upright position, leaning to the right hand, the motion will
be from east to west; but if they lean to the left hand, their motion
will be from west to east; and the nearer they are placed to an upright
position the less will be their motion either way. If the tubes be
placed on a sheet of glass, instead of moving towards the fire they
will move from it, and about the axis in a contrary direction from what
they did before; nay, they will recede from the fire, and move a little
upwards when the plane inclines towards the fire."
Glass is used for pendulums, as not being subject to affections from
heat or cold. It is, as is well known, a non-conductor. No metallic
condenser possesses an equal power with one of glass. In summer, when
moisture fails to collect on a metallic surface, open glass will gather
it on the exterior; the slightest breath of air evidently affecting the
glass with moisture. Dew will affect the surface of glass while
apparently uninfluential upon other surfaces.
The properties of so-called "musical glasses" are strikingly singular.
Glass bowls, partly filled with water, in various quantity, will, as is
well known, emit musical sounds, varying with the thickness of their
edges or lips. When rubbed, too, with a wet finger, gently, the water
in the glass is plainly seen to tremble and vibrate.
Bells manufactured of glass have been found the clearest and most
sonorous; the vibration of sound extending to a greater degree than in
metallic bells.
Glass resists the action of all acids except the "fluoric." It loses
nothing in weight by use or age. It is more capable than all other
substances of receiving the highest degree of polish. If melted seven
times over and properly cooled in the furnace, it will receive a polish
rivalling almost the diamond in brilliancy. It is capable of receiving
the richest colors procured from gold or other metallic coloring, and
will retain its original brilliancy of hue for ages. Medals, too,
embedded in glass, can be made to retain forever their original purity
and appearance.
Another singular property of glass is shown in the fact, that when the
furnace, as the workmen term it, is settled, the metal is perfectly
plain and clear; but if by accident the metal becomes too cool to work,
and the furnace heat required to be raised, the glass, which had before
remained in the open pots perfectly calm and plain, immediately becomes
agitated or boiling. The glass rises in a mass of spongy matter and
bubbles, and is rendered worthless. A change is however immediately
effected by throwing a tumbler of water upon the metal, when the
agitation immediately ceases, and the glass assumes its original quiet
and clearness.
All writers upon the subject of glass manufacture fail to show anything
decisive upon the precise period of its invention. Some suppose it to
have been invented before the flood. Nervi traces its antiquity to the
yet problematical time of Job.
It seems clear, however, that the art was known to the Egyptians
thirty-five hundred years since; for records handed down to us in the
form of paintings, hieroglyphics, &c., demonstrate its existence in the
reign of the first Osirtasen, and existing relics in glass, taken from
the ruins of Thebes, with hieroglyphical data, clearly place its
antiquity at a point fifteen centuries prior to the time of Christ.
Mr. Kennett Loftus, the first European who has visited the ancient
ruins of Warka, in Mesopotamia, writes thus: "Warka is no doubt the
Erech of Scripture, the second city of Nimrod, and it is the Orchoe of
the Chaldees. The mounds within the walls afford subjects of high
interest to the historian; they are filled, or I may say composed, of
coffins piled upon each other to the height of forty-five feet."
"The coffins are of baked clay, covered with green glaze, and embossed
with the figures of warriors, &c., and within are ornaments of gold,
silver, iron, copper, and _glass_."
Layard, in his discoveries among the ruins of Nineveh and Babylon, in
chapter 8th, says: "In this chamber were found two entire glass bowls,
with fragments of others. The glass, like all others that come from the
ruins, is covered with pearly scales, which, on being removed, leave
prismatic, opal-like colors of the greatest brilliancy, showing, under
different lights, the most varied tints. This is a well-known effect of
age arising from the decomposition of certain component parts of the
glass. These bowls are probably of the same period as the small bottle
found in the ruins of the northwest palace during the previous
excavations, and now in the British Museum. On this highly interesting
relic is the name of Sargon, with his title of King of Assyria, in
cuneiform characters, and the figure of a lion. We are therefore able
to fix its date to the latter part of the seventh century B.C. It is
consequently the most ancient known specimen of _transparent_ glass."
In chapters 22d and 25th, he gives us the form of many glass vessels
from the mound of Babel, similar in form to the modern fish-globes,
flower-vases and table water-bottles of the present day--the latter
being reeded must have been formed in metallic moulds--and pieces of
glass tubes, the exterior impression exactly like our modern patch
diamond figure.
Of the several specimens of glass brought to England by Mr. Layard,
one, the fragment of a vase, when examined, was of a dull green color,
as though incrusted with carbonate of copper. This color was quite
superficial, and the glass itself was opaque and of a vermilion tint,
attributed to suboxide of copper. The outer green covering was due to
the action of the atmosphere on the surface of the glass, and the
consequent change of the suboxide into green carbonate of copper. This
specimen is interesting, as showing the early use and knowledge of
suboxide of copper as a stain or coloring agent for glass. The ancients
employed several substances in their glass, and colored glazes for
bricks and pottery, but of which there remains no published record. But
these glasses and other ancient works of art prove that they were
familiar with the use of oxide of lead as a flux in their vitreous
glasses, and with stannic acid and Naples yellow as stains or pigments.
Other writers believe that glass was in more general use in the ancient
than in comparatively modern times, and affirm that among the Egyptians
it was used even as material for coffins. It is certainly true that so
well did the Egyptians understand the art, that they excelled in the
imitation of precious stones, and were well acquainted with the
metallic oxides used in coloring glass; and the specimens of their
skill, still preserved in the British Museum and in private
collections, prove the great skill and ingenuity of their workmen in
mosaic similar in appearance to the modern paper-weights. Among the
specimens of Egyptian glass still existing is a fragment representing a
lion in bas-relief, well executed and anatomically correct. Other
specimens are found inscribed with Arabic characters.
All writers agree that the glass-houses in Alexandria, in Egypt, were
highly celebrated for the ingenuity and skill of their workmen, and the
extent of their manufactures.
Strabo relates that the Emperor Hadrian received from an Egyptian
priest a number of glass cups in mosaic, sparkling with every color,
and deemed of such rare value that they were used only on great
festivals.
The tombs at Thebes, the ruins of Pompeii and Herculaneum, and the
remains of the villa of the Emperor Tiberius, go not only incidentally
to establish the antiquity of the art, but also prove the exquisite
taste and skill of the artists of their various periods.
The first glass-houses, well authenticated, were erected in the city of
Tyre. Modern writers upon the subject generally refer to Pliny in
establishing the fact that the Phoenicians were the inventors of the
art of glass-making. The tradition is that the art was originally
brought to light under the following circumstances. A vessel being
driven by a storm to take shelter at the mouth of the river Belus, the
crew were obliged to remain there some length of time. In the process
of cooking, a fire was made upon the ground, whereon was abundance of
the herb "kale." That plant burning to ashes, the saline properties
became incorporated with the sand. This causing vitrification, the
compound now called glass was the result. The fact becoming known, the
inhabitants of Tyre and Sidon essayed the work, and brought the new
invention into practical use. This is the tradition: but modern science
demonstrates the false philosophy, if not the incorrectness, of Pliny's
account; and modern manufacturers will readily detect the error, from
the impossibility of melting silex and soda by the heat necessary for
the ordinary boiling purposes.
It is a well-authenticated fact, however, that there were whole streets
in Tyre entirely occupied by glass-works; and history makes no mention
of any works of this character at an earlier period than the time
mentioned by Pliny.
That Tyre possessed peculiar advantages for the manufacture, is very
clear from geographical and geological data, the sand upon the shore at
the mouth of the river Belus being pure silica, and well adapted to the
manufacture. The extensive range of Tyrian commerce, too, gave ample
facilities for the exportation and sale of the staple; and for some
ages it must have constituted almost the only article, or at least the
prominent article, of trade. Doubtless the rich freights of "the ships
of Tyre," mentioned in Scripture, may in part have been composed of a
material now as common as any of its original elements.
From Tyre and Sidon the art was transferred to Rome. Pliny states it
flourished most extensively during the reign of Tiberius, entire
streets of the city being then occupied by the glass manufactories.
From the period of Tiberius the progress of the art seems more definite
and marked, both as relates to the quantity and mode of manufacture.
It was during the reign of Nero, so far as we can discover, that the
first perfectly clear glass, resembling crystal, was manufactured.
Pliny states that Nero, for two cups of ordinary size, with handles,
gave six thousand sestertia, equal in our currency to about two hundred
and fifty thousand dollars; and that rich articles of glass were in
such general use among the wealthy Romans as almost to supersede
articles of gold and silver. The art, however, at that period, seems to
have been entirely devoted to articles of luxury, and from the great
price paid, supported many establishments,--all however evidently upon
a comparatively small scale, and confined, as it would appear, to
families.
Up to this period, no evidence appears to prove that any other than
colored articles in glass-ware were made. It is clear, too, that the
furnaces and melting-pots then in use were of very limited capacity,
the latter being of crucible shape; and it was not until the time of
Nero that the discovery was made that muffled crucibles or pots, as at
the present day, were required in order to make crystal glass. (Without
them, it is well known, crystal glass cannot be perfected.) It appears,
further, that a definite street in the city of Rome was assigned to the
manufacturers of this article; and that in the reign of Severus they
had attained such a position, and accumulated wealth to such a degree,
that a formal tax was levied upon them. Some writers take the ground
that this assessment was the primary cause of the transfer of the
manufacture to other places.
That the peculiar property of the manufacture at this period was its
clear and crystal appearance is abundantly evident; and this, and the
great degree of perfection to which the manufacture of white or
crystal-like glass was carried, are by many writers thought to have
been proved from classical sources,--Horace and Virgil both referring
to it, the one speaking of its beautiful lustre and brilliancy, the
other comparing it to the clearness of the waters of the Fucine Lake.
The decline of this art in Rome is clearly defined by various writers;
and its gradual introduction into Bohemia and Venice is plainly marked
out. At this latter place the art flourished to a remarkable degree,
and being marked by constant progress and improvement, enabled Venice
to supply the world without a rival, and with the beautiful manufacture
called "Venice drinking-cups." The beauty and value of these are
abundantly testified to by many authors, among whom is Holinshed,
referred to previously. The manufacture of these and similar articles
were located, as stated in the "Chronicles," at Murano, a place about
one mile from the city, where the business was carried on, and assumed
a high position in the order of the arts. And from thence we are
enabled to date its future progress and gradual introduction into
Europe, Germany, England, and the Western World.
It is not strange that the strict secrecy with which the business was
conducted in these times, should have invested the art with an air of
romance; and legends, probably invented for the purpose, created a
maximum of wonder among the uninitiated. The government of Venice also
added, by its course, to the popular notions regarding the high mystery
of the art, conferring, as it did, the title of "Gentleman" (no idle
title in those days) on all who became accomplished in the manufacture.
Howell, in his "Familiar Letters," dated from Venice in 1621, says:
"Not without reason, it being a rare kind of knowledge and chemistry,
to transmute the dull bodies of dust and sand, for they are the only
ingredients, to such pellucid, dainty body, as we see crystal glass
is."
That the art had greatly improved in the hands of the Venetian artisans
cannot be doubted. The manufacture was carried to a degree far beyond
any previous period; and the more so, because sustained by the
governmental protection and patronage. Venice being then in the height
of her commercial glory, she herself being "Queen of the Sea," ample
facilities existed for the exportation of her manufactures to every
part of the known world; and for a long period she held the monopoly of
supplying the cities of Europe with crystal glass in its various
departments of ornament and utility.
A French writer, who published an elaborate work in twelve books upon
the subject of glass manufacture, after it had been introduced into
France, gives an interesting account of the rise and progress of the
art in that country, the encouragement it received, and the high
estimation in which it was held. After stating that it was introduced
into France from Venice, he says:--
"The workmen who are employed in this noble art are all gentlemen, for
they admit none but such. They have obtained many large privileges, the
principal whereof is to work themselves, without derogating from their
nobility. Those who obtained these privileges first were gentlemen by
birth; and their privilege running, that they may exercise this art
without derogating from their nobility, as a sufficient proof of it,
which has been confirmed by all our kings; and in all inquiries that
have been made into counterfeit nobilities, never was any one attainted
who enjoyed these privileges, having always maintained their honor down
to their posterity."
Baron Von Lowhen states, in his "Analysis of Nobility in its Origin,"
that, "So useful were the glass-makers at one period in Venice, and so
considerable the revenue accruing to the republic from their
manufacture, that, to encourage the men engaged in it to remain in
Murano, the Senate made them all Burgesses of Venice, and allowed
nobles to marry their daughters; whereas, if a nobleman marries the
daughter of any other tradesman, the issue is not reputed noble."
From this statement a valuable lesson can be drawn, viz., that a strict
parallel is constantly observable between the progress of this art and
the intellectual and social elevation of its possessors.
Those engaged in it now do not indeed occupy the same social position;
still it is probable that in foreign lands the blood of noble ancestors
still runs in their veins; and even in our own democratical land, with
all the tendencies of its institutions, workers in glass claim a
distinctive rank and character among the trades; and in the prices of
labor, and the estimate of the comparative skill involved, are not
controlled by those laws of labor and compensation which govern most
other mechanical professions; and similarity of taste and habit is in a
degree characteristic of the modern artisan in this department, as in
the case of those who, for their accomplishment in the art, were
ennobled in the more remote period of its progress. The same writer
says:--
"It must be owned those great and continual heats, which those
gentlemen are exposed to from their furnaces, are prejudicial to their
health; for, coming in at their mouths, it attacks their lungs and
dries them up, whence most part are pale and short-lived, by reason of
the diseases of the heart and breast, which the fire causes; which
makes Libarius say, 'they were of weak and infirm bodies, thirsty, and
easily made drunk,'--this writer says, this is their true character:
but I will say this in their favor, that this character is not general,
having known several without this fault."
Such was the character and habits of noble glass-makers four hundred
years since; and whether their descendants still retain their blood or
not, the habit of drinking, believed at that time necessary as
consequent upon the nature of the employment, is, at the present day,
confined to the ignorant, dissolute, and unambitious workmen. The habit
will, doubtless, ere long be done away. Still, so long as the workmen
of the present day cling to their conventional rules,--act as one body,
the lazy controlling the efforts of the more intelligent and
industrious,--so long will the conduct of the dissolute few affect the
moral reputation of the entire body. They must not forget the old
adage, that "One bad sheep taints the whole flock." The spirit of the
age in no degree tends to sustain the old saying, that "Live horses
must draw the dead ones."
The writer already referred to, dwelling with great interest upon the
social position of those then engaged in the art, goes on to say:--
"Anthony de Brossard, Lord of St. Martin and St. Brice, gentleman to
Charles d'Artois, Count of Eu, a prince of noble blood royal, finding
this art so considerable, that understanding it did not derogate from
their nobility, obtained a grant in the year 1453 to establish a
glass-house in his country, with prohibition of any other, and several
other privileges he had annexed to it. The family and extraction of
this Sieur de Brossard was considerable enough to bring him here as an
example. The right of making glass being so honorable, since the elder
sons of the family of Brossard left it off, the younger have taken it
up, and continue it to this day. Messieurs de Caqueray, also gentlemen
of ancient extraction, obtained a right of glass-making, which one of
their ancestors contracted by marriage in the year 1468 with a daughter
of Anthony de Brossard, Lord of St. Martin, that gentleman giving half
of his right for part of her fortune, which was afterwards confirmed in
the Chamber of Accounts. Messieurs Valliant, an ancient family of
gentlemen, also obtained a grant of a glass-house for recompense of
their services, and for arms a Poignard d'Or on azure, which agrees
with their name and tried valor. Besides these families, who still
continue to exercise this art, there are the Messieurs de Virgille, who
have a grant for a little glass-house. Messieurs de la Mairie, de
Suqrie, de Bougard, and several others, have been confirmed in their
nobility during the late search in the year 1667.
"We have, moreover, in France, several great families, sprung from
gentlemen glass-makers who have left the trade, among whom some have
been honored with the purple and the highest dignities and offices."
Enough is recorded to show in what estimation the art was held in
France by the government and people of that period; and it is in nowise
wonderful that an art invested with so much distinction, conducted with
so much secrecy, and characterized with so great a degree of romantic
interest, should have given rise to strange reports and legends,
hereafter to be referred to.
The writer referred to above states that there were two modes of
manufacturing glass. One he denominates that of the "Great
Glass-Houses," the other the "Small Glass-Houses." In the large houses
the manufacture of window-glass, and bottles for wine or other liquors,
was carried on. He states:--
"The gentlemen of the Great Glass-Houses work only twelve hours, but
that without resting, as in the little ones, and always standing and
naked. The work passes through three hands. First, the gentlemen
apprentices gather the glass and prepare the same. It is then handed to
the second gentlemen, who are more advanced in the art. Then the master
gentleman takes it, and makes it perfect by blowing it. In the little
glass-houses, where they make coach-glasses, drinking-glasses,
crystals, dishes, cups, bottles, and such like sort of vessels, the
gentlemen labor but six hours together, and then more come and take
their places, and after they have labored the same time they give
places to the first; and thus they work night and day, the same workmen
successively, as long as the furnace is in a good condition."
Every glass-maker will perceive, from the foregoing description, that
the same system prevails at the present time, as to the division of
labor and period of labor, so far at least as "blown articles" are
concerned. The names, too, then given to glass-makers' tools are
retained to the present day, and, with slight difference, the shapes of
the various tools are the same.
At the best, the manufacturers of glass in France were for a long
period much inferior to the Venetians and Bohemians; but after the
introduction of window-glass, from Venice, the making of crystal glass
greatly extended and correspondingly improved.
In the year 1665 the government of France, desirous of introducing the
manufacture of window-glass, offered sufficient inducement in money and
privileges to a number of French artists (who had acquired the process
at Murano, at Venice) to establish works at Tourtanville. At these
works the same system of blowing was followed as that used in the
Venetian glass-works. A workman, under this system, named Thevart,
discovered the art of casting plate-glass, and obtained from the
government a patent for the term of thirty years. He erected extensive
works in Paris, and succeeded in what was then deemed an extraordinary
feat, casting plates eighty-four inches by fifty inches, thereby
exciting unbounded admiration.
The credit of the invention of casting plates of glass belongs to
France, and the mode then adopted exists at the present day, with but
slight variation. France monopolized the manufacture over one hundred
years before it was introduced into any other country.
Writers generally agree that the manufacture of glass was introduced
into England in the year 1557. "Friars' Hall," as stated by one writer,
was converted into a manufactory of window-glass,--other writers say,
for crystal glass, (called by the English "flint," from the fact of the
use of flint-stones, which, by great labor, they burnt and ground.) In
1575 Friars' Hall Glass-Works, with forty thousand billets of wood,
were destroyed by fire.
In 1635, seventy-eight years after the art was introduced into England,
Sir Robert Mansell introduced the use of coal fuel instead of wood, and
obtained from the English government the monopoly of importing the fine
Venetian drinking-glasses, an evidence that the art in England was
confined as yet to the coarser articles. Indeed, it was not until the
reign of William III. that the art of making Venetian drinking-vessels
was brought into perfection,--quite a century after the art was
introduced into England; an evidence of the slow progress made by the
art in that country.
As France was indebted to Venice for her workmen, so also was England
indebted to the same source. Howell, in one of his "Familiar Letters,"
directed to Sir Robert Mansell, Vice-Admiral of England, says: "Soon as
I came to Venice, I applied myself to dispatch your business according
to instruction, and Mr. Seymour was ready to contribute his best
furtherance. These two Italians are the best gentlemen workmen that
ever blew crystal. One is allied to Antonio Miotte, the other is cousin
to Maralao."
Although Sir Robert procured workmen from Venice, they were probably of
an inferior character, and a space of fifty years elapsed before the
English manufactories equalled the Venetian and French in the quality
of their articles.
Evelyn, in his "Diary," states: "On the proclamation of James II., in
the market-place of Bromley, by the sheriff of Kent, the commander of
the Kentish troops, two of the King's trumpeters, and other officers,
drank the King's health in a flint wine-glass three feet tall."
In the year 1670, the Duke of Buckingham became the patron of the art
in England, and greatly improved the quality and style of the
flint-glass, by procuring, at great personal expense, a number of
Venetian artists, whom he persuaded to settle in London. From this
period, _i.e._, about the commencement of the eighteenth century,
the English glass manufactories, aided by the liberal bounties granted
them in cash upon all glass exported by them or sold for export, became
powerful and successful rivals of the Venetian and the French
manufactories in foreign markets. The clear bounty granted on each
pound of glass exported from England, which the government paid to the
manufacturer, was not derived from any tax by impost or excise
previously laid, for all such were returned to the manufacturer,
together with the bounty referred to; thereby lessening the actual cost
of the manufacture from twenty-five to fifty per cent., and enabling
the English exporters to drive off all competition in foreign markets.
This bounty provision was annulled during the Premiership of Sir Robert
Peel, together with all the excise duty on the home consumption.
In 1673 the first plate-glass was manufactured at Lambeth, under a
royal charter; but no great progress was made at that time, and the
works for the purpose were doubtless very limited. One hundred years
later, _i.e._ 1773, a Company was formed, under a royal charter,
called the "Governor and Company of the British Cast Plate-Glass
Manufactory," with a capital of eighty shares of five hundred pounds
each, their works being at Ravenshead, in Lancashire. These works have
been very successfully conducted, and, according to a late writer, are
rivalled by none, excepting those at "St. Gobain," in France. Since the
excise duty on plate-glass has been repealed, its manufacture has
increased to a wonderful extent; the quantity used in the construction
of the Crystal Palace, for the World's Fair, being probably many times
larger than that manufactured twenty years since in the kingdom of
Great Britain in any one year.
An English paper states that Roger Bacon, at sixty-four years of age,
was imprisoned ten years for making concave and convex glasses, and
camera-obscura and burning-glasses.
It is to many persons matter of great surprise that the manufacture of
plate-glass has never been introduced into this country. The whole
process is a simple one. The materials are as cheap here as in England
or in France. Machinery for the polishing of the surface is as easily
procured, and water-power quite as abundant, as in either country. The
manufacture, with the materials so ready to the hand, and these
together with the skill, labor, and demand, increasing every year, is
most certain to realize a fair remunerating profit and steady sale.
Besseman has lately introduced a new method of casting plate-glass,
which, should it equal the inventor's expectation, will reduce the
cost, supersede the old plan, and eventually, of course, increase the
consumption.