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CERAMICS, or KERAMICS (Gr. KEpapos, e...
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See also:CERAMICS, or KERAMICS (Gr. KEpapos, earthenware)
, a See also:general See also:term for the study of the See also:art of pottery
.
It is adopted for this purpose both in See also:French (ceramique) and in See also:German (Keramik), and thus has its convenience in See also:English as representing an inter-See also:national See also:form of description for a study which owes much to the art experts of all nations, though " ceramic " and " See also:ceramics " do not appear in English as technical terms till the See also:middle of the 19th See also:century
.
The word " pottery " (Fr. poterie) in its widest sense includes all See also:objects fashioned from See also:clay and then hardened by See also:fire, though there is a growing tendency to restrict the word to the commoner articles of this See also:great class and to apply the word "See also:porcelain" to all the finer varieties
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This tendency is to be deprecated, as it is founded on a misconception; the word " porcelain " should only be applied to certain well-marked varieties of pottery
.
The very existence of pottery is dependent on two important natural properties of that great and widespread See also:group of rocky or earthy substances known as See also:clays, viz. the See also:property of plasticity (the See also:power of being readily kneaded or moulded while moist), and the property of being converted when fired into one of the most indestructible of See also:ordinary things
.
The clays form such an important group of See also:mineral substances that the reader must refer to the See also:article CLAY for an See also:account of their occurrence, See also:composition and properties
.
In this article we shall only See also:deal with the various clays as they have affected the problems of the See also:potter throughout the ages
.
The clays found on or See also:close to the See also:earth's See also:surface are so varied in composition and properties that we may see in them one of the vital factors that has determined the nature of the pottery of different countries and different peoples
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They vary in plasticity, and in the hardness, See also:colour and texture of the fired product, through an astonishingly wide range
.
To-See also:day the See also:fine, plastic, See also:
Fired in an open fire, or in the most rudimentary form of potter's See also:kiln, such pottery may be See also:buff, drab, See also: When we possess a sufficient See also:body of See also:analytical data obtained by the use of one general chemical method, an See also:analysis of a fragment will frequently enable such a question to be answered, where now all is doubt and See also:speculation . Rut the analytical results published hitherto are often not See also:worth the See also:paper they are printed on for such a purpose, the older methods of silicate analysis being only approximate . of plastic form, and then, excited by their growing skill in See also:metal work, turn the plastic clay into imitations of metal forms . These nations are overthrown, and the Romans spread some knowledge —only a See also:tincture, it must be confessed--over all the lands they hold in See also:fee; and from the See also:Euphrates to the See also:Atlantic, from Egypt to the See also:Wall of See also:Hadrian, they set alight potters' fires that have never since been extinguished . The See also:Roman See also:empire falls, and over Europe its pottery is forgotten along with its greater achievements; yet still pottery-making goes on in a very simple way, to be slowly revived and modified once more by the communities of monks, who, in later centuries, replace the Roman legions as the great civilizing influence in Europe . Meantime Egypt and the nearer See also:East continued, in a debased form, the splendours of their glorious past, and glazed and painted pottery was still made by traditional methods . What part the See also:Byzantine See also:civilization and the Persians played during this obscure See also:time, we are only just beginning to realize; but we now know that many interesting kinds of decorated pottery were made at Old See also:Cairo, at See also:Alexandria, at See also:Damascus, in See also:Syria, See also:Anatolia and elsewhere (on which the later Moslem potters founded their glorious See also:works), at a time when all over Europe crocks of simple red or drab clay, covered only with See also:green and yellow See also:lead-glazes, were the See also:sole evidence of the potter's skill . What the Arab conquests destroyed, and what their breath quickened into See also:life, we can only guess; but the fact is indisputable that with the See also:Mahommedan See also:con-quests there came a time when the potter's art of the Occident reached its highest expression, and when methods and knowledge hitherto confined to Egypt, Syria and See also:Persia were spread from Spain and the south of See also:France to See also:India—even, it may be, into See also:China . Meantime, in the farther East, the Chinese—the greatest race of potters the world has ever seen—were quietly gathering strength, until from their glazed, hard-fired pottery there emerged the marvellous, white translucent porcelain, one of the wonders of the See also:medieval world . With the dawn of the 15th century of our era, the state of affairs was practically this:—In See also:European countries proper we find rudely fashioned and decorated wares in which we can trace the slow development of a native See also:craft from the superposition of Roman methods on the primitive work of the peoples . The vessels were mostly intended for use and not for show; were clumsily fashioned of any See also:local clay, and if glazed at all then only with coarse lead-glazes, coloured yellow or green; in no See also:case above the level of workmanship of the travelling See also:brick- or See also:tile-maker . The finest expression of this native See also:style is to be found in the See also:Gothic tile pavements of France, See also:Germany and England, where all the See also:colours are due to the clays and there is no approach to See also:painting .
In the Moslem countries—including the greater part of Spain and See also:Sicily, Egypt and the nearer East, probably even to the very centre of See also:Asia—pottery was being made either of whitish clay and sand, or of a See also:light reddish clay coated with a white facing of fine clay or of See also:tin-See also:enamel, on which splendid decorative patterns in vivid See also:pigments or brilliant iridescent lustres were painted
.
As See also:early as the 12th century of our era this See also:superior See also:artistic pottery of the Moslem nations had already attracted the See also:notice of Europeans as an article of luxury for the wealthy; and we may well believe the traditional accounts that Saracen potters were brought into Italy, France and See also:Burgundy to introduce the practice of their art, while See also:Italian potters certainly penetrated into the workshops of eastern Spain and elsewhere, and gathered new ideas
.
In Italy certainly, and in the south of France probably, efforts were continuously in progress to improve the native wares by coating the vessels with a white " slip " and See also:drawing on them rude, painted patterns in green, yellow and purplish black
.
The increasing intercourse with Spain, in See also:war and See also:peace, also introduced the use of tin-enamel after the fashion of the famous Hispano-Moresque wares, and by the end of the 14th century a knowledge of tin-enamel was widespread in Italy and paved the way to the glorious painted See also:majolica of the 15th and 16th centuries
.
From Italy and Spain, France and See also: By the end of the 18th century the risks and losses attendant on the manufacture of the French glassy porcelain had caused its See also:abandonment, and a porcelain made from natural materials like the Chinese has since been generally made on the See also:continent of Europe . The older tin-enamelled wares—derived from the Hispano-Moresque and the Italian majolica—so largely made in France, Holland, Germany and elsewhere during the 17th and 18th centuries, met with a See also:fate analogous to that of the French porcelain . Tin-enamelled earthenware is always a brittle substance, soon damaged in See also:regular use; so that, when, in the middle of the 18th century, the English potter first appeared as a serious competitor with a fine white earthenware of superior durability and precision of manufacture, the old painted See also:faience gradually disappeared between the upper millstone of European porcelain and the nether millstone of English earthenware . The 19th century witnessed a great and steady growth in the output of porcelain and pottery of all kinds in Europe and the See also:United States . See also:Mechanical methods were largely called in to supplement or replace what had hitherto remained almost pure handicraft . The English methods of preparing and mixing the materials of the body and glaze, and the English See also:device of replacing painted decoration by See also:machine See also:printing, to a large extent carried the day, with a great gain to the mechanical aspects of the ' It must always be See also:borne in mind that, side by side with the See also:production of artistic wares in all countries, the traditional craft of the See also:village pot-maker continued, and has probably been less interfered with than is generally imagined, except in the See also:British Isles . Any country See also:market-place in Spain . Italy, Greece, France, Germany, or Holland is provided to-day with a simple See also:peasant pottery little removed in its forms, its decorations, or its technical skill from the country work of the middle ages . In England the cheapness of machine-made pottery has largely destroyed such village See also:industries . GENERAL] work and in many cases with an entire extinction of its artistic spirit . Even the hand-work that still remained was largely affected by the growing dominance of machinery; and the painting, See also:gilding and decoration of pottery and porcelain, in the first See also:half of the 19th century, became everywhere mechanical and hackneyed . During the latter half of the 19th century another influence was fortunately at work . Side by side with the increasing mechanica' perfection of the great bulk of modern pottery there See also:grew up a school of innovators and experimentalists, who revived many of the older decorative methods that had fallen into oblivion and produced fresh and original work, in certain directions even beyond, the achievements of the past . The loth century opened with a wider outlook among the potters of Europe and America . In every country men were striving once again to bring back to their world-old craft something of artistic See also:taste and skill . Technical Methods.— All primitive pottery, whether of ancient or of modern times, has been made by the simplest methods . The clay, dug from the earth's surface, was or is prepared by beating and kneading with the hands, feet or simple mallets of stone or See also:wood; stones and hard particles were picked out; and the See also:mass, well tempered with See also:water, was used without any addition . From this clay, vessels were shaped by scooping out or cutting a solid lump or See also:ball, by building up piece by piece and smoothing down one layer upon another or by squeezing cakes of clay on to some natural See also:object or prepared See also:mould or form . The potter's wheel, though very ancient, was a comparatively See also:late invention, arrived at independently by many races of men . In its simplest form it was a heavy disk pivoted on a central point to be set going by the hand, as the workman squatted on the ground; and it may be seen to-day in India, See also:Ceylon, China or See also:Japan, in all its primitive simplicity (see fig . I) . This form of potter's wheel was the only one known until about the See also:Christian era, and then, in Egypt apparently, the improvement was introduced of lengthening the spindle which carries the throwing-wheel and mounting on it near the See also:base a much larger disk which the potter could rotate with his See also:foot, and so have both hands See also:free for the manipulation of the clay (fig . 2) . No further advance seems to have been made before the 17th century, when the wheel was spun by means of a See also:cord working over a See also:pulley; and though a See also:steam-driven wheel was introduced in the middle of the 19th century, this form remains the best for the production of fine pottery . A prevalent misconception with regard to the potter's wheel needs correction . For anything beyond very simple shapes it is impossible to carry the work to completion on the wheel at one operation as is generally imagined . Ail that the potter can do while the clay is soft enough to " throw " on the wheel is to get a rough shape of even thickness . This operation completed, the piece is removed from the wheel and set aside to dry . When it is about See also:leather-hard, it may be re-centred carefully on the wheel (the old practice), or placed in a See also:horizontal See also:lathe (since 16th century) and turned down to the exact shape and polished to an even, smooth surface . The Greek vase-makers were already adepts in what is often reckoned a modern, detestable practice . Many Greek vases have obviously been " thrown " in See also:separate sections, and when these had contracted and hardened sufficiently they were luted together with slip, and the final vase-shape was smoothed and turned down on the wheel, and even polished to as fine a degree of mechanical finish as the modern potter ever attains . So too with the Chinese; many of their forms have been made in two or three portions, subsequently joined together and finished on the outside as one piece . Indeed; it is remarkable how the Greeks and Chinese had discovered for themselves many devices of this See also:kind which are generally held up to opprobrium as the debased methods of a mechanical See also:age . V . 23705 Always it should be borne in mind that the shaping of pottery by " pressing " cakes of clay into moulds is much older than the potter's wheel, and has always been the method of making shapes other than those in the See also:round . The modern method of " casting " pottery by pouring slip, a fluid mixture of clay and water, into absorbent moulds seems to have originated in England about the middle of the 18th century; and this too is a genuine potter's method which does not merit the disapproval with which it has been generally regarded by writers on the potter's art . 
In all ages the work of the " thrower " or " presser " has been largely supplemented by the modeller, who alters the shape, and applies to it handles, spouts or modelled accessories at will . Firing.—The firing of pottery has become in modern times such a specialized See also:branch of the manufacture that the student can only be referred here to the technological works mentioned in the bibliography at the end of this article . It is, however, necessary that we should briefly describe the earlier forms of potters' kilns used by the nations whose pottery See also:counts among the treasures of the See also:collector and the See also:antiquary . Here again we now know that the primitive types of kiln used by the potters of ancient Egypt or Greece have not vanished from the earth; it is only in the civilized countries of the modern world that they have been replaced by improved and perfected devices . The potters of the See also:North-See also:West Provinces of India use to-day a kiln practically identical with that depicted in severest See also:silhouette on the See also:rock-tombs of See also:Thebes; and the skilful Japanese remain content with a kiln very similar to the one shown in fig . 3 . This Greek type of kiln was improved and enlarged by the Romans, and its use seems to have been introduced wherever pottery was made under their sway, for remains of Roman kilns have been found in many countries (see fig . 4) . With the end of Roman dominance we have ample evidence that their technical methods See also:fell into disuse, and the northern European potter of the See also:period from the 6th to the 12th century had to build up his methods afresh, and improved kilns were invented . The general type of medieval potter's kiln is illustrated for us in the See also:manuscript of an Italian potter of the 16th century, now in the library of the See also:Victoria and See also:Albert Museum 1 (fig . 5) . Kilns of a different type, horizontal reverberatory kilns, were used for making the hard-fired pottery of 1 I tre libri dell' Arte del Vasajo, by Cipriano Piccolpasso of See also:Castel See also:Durante, A.D . 1548 . II Europe (Rhenish stoneware, &c.), as well as for Chinese porcelain and the earliest German porcelains . With the organization of pottery as a factory See also:industry in the 18th century, improved kilns were introduced, and the type of kiln now so largely used in civilized countries is practically a See also:vertical reverberatory See also:furnace of circular See also:section, from 10 to 22 ft. in See also:diameter and of similar height, capable, there-fore, of containing at one firing a quantity of pottery that would have formed the output of a medieval potter for a See also:year . Every device that can be thought of for the better utilization of See also:heat and its even See also:distribution throughout the kiln or See also:oven has been experimented with; and, though the results have been most successful from the point of view of the potter, even the most recent See also:coal-fired ovens remain very wasteful types of apparatus, the amount of available heat being relatively small to the See also:fuel See also:consumption . See also:Gas-fired kilns and ovens are now being used or experimented with in every country, and their perfection, which cannot be far distant, will improve the most vital of the potter's processes both in certainty and See also:economy . Glazes.—We are never likely to known when glaze (i.e. a coating of fired glass) was first applied to pottery, though the See also:present state of knowledge would incline us to the See also:opinion that the earliest glazed objects we possess are those of ancient Egypt,' but the practice may have been originated independently wherever a knowledge of the elements of glass-making had spread, as all the early glazes were of the alkaline type, which must first be fused into a glass before they can be applied to pottery . Many primitive races seem to have burnished their pottery after it was fired, in See also:order to get a glossy surface; and in other cases the surface was rendered shining and waterproof by coating it with waxy or resinous substances which were often coloured . It is possible that the black See also:varnish of Greek vases was obtained by such a method, and though that point is not settled, we have many types of primitive pottery, both modern and ancient, which are coated in this way . Such a coating is only a substitute for glaze in the work of peoples who do not know or have not mastered the technical secrets of true glazes . We can only consider as glazes those definite superficial layers of molten material which have been fired on the clay substance . Glazes are as varied as the various kinds of pottery, and it must never be forgotten that each kind of pottery Is at its best with its appropriate glaze . The earliest known glazes (Egyptian and See also:Assyrian) were silicates of soda and See also:lime containing very little alumina and no lead . Such glazes are very uncertain in use, and can only be applied to pottery unusually See also:rich in See also:silica (i.e. deficient in clay) . Consequently these alkaline glazes cannot be used on ordinary clay wares, and when they have been used successfully, the clay has always been coated with a surface layer of highly siliceous substance (e.g. the so-called See also:Persian, Rhodian, Syrian and Egyptian pottery of the early middle ages) . The fact that glazes containing lead-See also:oxide would adhere to ordinary pottery when alkaline glazes would not was discovered at a very early period; for lead glazes were extensively used in Egypt and the nearer East in Ptolemaic times, and it is significant that, though the Romans made singularly little use of glazes of any kind, the pottery that succeeded theirs, either in western Europe or in the Byzantine empire, was generally covered with glazes rich in lead . Throughout Europe, and over the greater part of the world, leaded glazes have been continuously used and improved for all ordinary pottery, and it is only with certain special hard-fired types of See also:ware that they have yet been successfully replaced . Chinese porcelain and all the European porcelains made by analogous methods are fired at so high a temperature that a glaze by See also:felspar softened by lime and silica is found most suitable for them, and the hard-fired stonewares, rich in silica, are often glazed with a See also:salt glaze, or a melted earth rich in oxide of See also:iron . Every kind of potter's clay (the mixture of clay, sand, See also:flint, &c., from which the potter shapes his wares) has its own type of glaze, and from the earliest time down to our own what the potter could produce in form or glaze or colour has been largely decided for him by the clay material at his command . With any See also:good plastic See also:play ' The earliest glazed objects found in Egyptian tombs (once dignified by the name of Egyptian porcelain) are hardly to be called pottery at all, though we have no other name for them . The material is largely sand held together by a little clay and glass.which cannot be fired at the highest temperature, lead glazes have always proved the most practicable . A similar clay, to which large quantities of sand are added, may be glazed by the vapours of See also:common salt; and mixtures rich in felspar, like Chinese or European porcelain, can be glazed by melting felspathic materials upon them . Naturally those species of pottery which are the hardest fired are the most durable—the glazes of hard porcelain are more unchangeable than lead glazes, and these in their turn than alkaline glazes . The most important types of glaze are (I) alkaline glazes (e.g . Egyptian, Syrian, Persian, &c.), the See also:oldest and most uncertain; (2) lead glazes, the most widespread in use and the best for all ordinary purposes; (3) felspathic glazes, the glazes of hard-fired porcelains, generally unsuited to any other material; (4) salt glaze, produced by vapours of common salt, the special glaze of stonewares . Many intermediate glazes have been devised to meet special needs, but these remain the only important See also:groups . See also:Fuller details on this important subject must be sought in the technical works . Colours.—The primitive potters of ancient and modern times have all striven to decorate their wares with colour . The simplest, and therefore the earliest, colour decoration was carried out in natural earths and clays . The clays are so varied in composition that they fire to every shade of colour from white to grey, cream, buff, red, brown, or even to a See also:bronze which is almost black . One clay daubed or painted upon another formed the primitive See also:palette of the potter, especially before the invention of glaze . When glaze was used these natural clays were changed in tint, and native earths, other than clays, containing iron, See also:manganese and See also:cobalt, were gradually discovered and used . It is also surprising to See also:note that some of the very earliest glazes were coloured glasses containing See also:copper or iron (the green, See also:turquoise and yellow glazes of the ancient Egyptians and Assyrians) . Marvellous work was wrought in these few materials, but the era of the finest pottery-colour dawns with the Persian, Syrian and Egyptian work that preceded the See also:Crusades . By this time the art of See also:glazing pottery with a clear soda-lime glaze had been thoroughly learnt . Vases, tiles, &c., shaped in good plastic clay, were covered with a white, highly siliceous coating See also:fit to receive glazes of this type, and giving the best possible ground for the painted colours then known . With this rudimentary technique the potters of the countries |