Tile, in Architecture

Tile, In Architecture

is a thin plate of baked clay used to cover roofs. In England there are but two kinds of tiles in ordinary use, plain tiles and pan tiles. The former of these, which are by far the commonest, are perfectly flat, the latter are curved, so that when laid upon a roof each tile overlaps the edge of the next to it and protects the joint from the wet.

The Romans used flat tiles turned up at the edges, with a row of inverted, semi-cylindrical ones over the joint to keep out the wet. In the Middle Ages tiles were extensively employed in England for covering buildings, though they seem always to have been considered an. inferior material to lead. It does not appear that any but flat, plain tiles, with such others as were requisite for the ridges, hips, and valleys, were used. The ridge-tiles, or crest, formerly also called roof-tiles, were sometimes made ornamental. It is not unusual to find the backs of fireplaces formed of tiles, and in such situations they are sometimes laid in herring bone courses, as in the great hall, Kenilworth: most of the fireplaces in Bodiam Castle, Sussex, are constructed in this manner, and the oven by the side of the larger fireplace in the hall is also built of tiles.

Glazed decorative tiles were anciently much used for paving sacred edifices. They are sometimes called Norman tiles, possibly from the supposition that they were originally made in Normandy; and, considering the age and variety of specimens that exist in Northern France; this idea may not be wholly erroneous. It is doubtful, however, whether any tiles have been discovered is England that present the features of the Norman style of architectural decoration, the most ancient being apparently of the 13th century. The name of encaustic has also been given to these tiles, and it would not be inappropriate were it not applied already to denote an antique process of art of a perfectly different nature; whereas a method wholly distinct, and peculiar to the glazed tiles of the Middle Ages, was commonly adopted in Northern Europe. The process of manufacture which, as it is supposed, was most commonly employed may be thus described: The thin squares of well-compacted clay having been fashioned, and probably dried in the sun to the requisite degree, their ordinary dimension being from four to six inches, with a thickness of one inch, a stamp which bore a design in relief was impressed upon them, so as to leave the ornamental pattern in cavetto. Into the hollows thus left on the face of the tile clay of another color, most commonly white, or pipe-clay, was then inlaid or impressed. Nothing remained except to give a richer effect, and, at the same time, insure the permanence of the work by covering the whole in the furnace with a thin surface of metallic glaze, which, being of a slightly yellow color, tinged the white clay beneath it, and imparted to the red a more full and rich tone of color. In the success of this simple operation much depended upon this that the quality of the two kinds of clay that were used should be as nearly similar as possible, or else, if the white was liable to shrink in the furnace more than the red, the whole work would be full of cracks; in the other case, the design would bulge and be thrown upward imperfections, of which examples are not wanting. To facilitate the equal drying of the tile, deep scorings or hollows were sometimes made on the reverse, and by this means, when laid in cement, the pavement was more firmly held together. Occasionally, either from the deficiency of white clay of good quality, or perhaps for the sake of variety, glazed tiles occur which have the design left hollow, and not filled in, according to the usual process, with clay of a different color. A careful examination, however, of the disposition of the ornament will frequently show that the original intention was to fill these cavities, as in other specimens; but instances also present themselves where the ornamental design evidently was intended to remain in relief, the field, and not the pattern, being found in cavetto. It must be observed that instances are very frequent where, the protecting glaze having been worn away, the white clay, which is of a less compact quality than the red, has fallen out and left the design hollow, so that an impression or rubbing may readily be taken. It appears probable that the origin of the fabrication of decorative pavements by the process which has been described is to be sought in the medieval imitations of the Roman mosaic-work by means of colored substances inlaid upon stone or marble. Of this kind of marquetry in stone, few examples have escaped the injuries of time; specimens may be seen on the eastern side of the altar-screen in Canterbury Cathedral, and at the abbey church of St. Denis and the cathedral of St. Omer.

Among the earliest specimens of glazed tiles may be mentioned the pavement discovered in the ruined priory church at Castle Acre, Norfolk, a portion of which is in the British Museum. These tiles are ornamented with escutcheons of arms, and on some appears the name "Thomas:" they are coarsely executed, the cavities are left and not filled in with any clay of different color.

A profusion of good examples still exists of single tiles, and sets of four, nine, sixteen, or a greater number of tiles, forming by their combination a complete design, and presenting, for the most part the characteristic style of ornament which was in vogue at each successive period, but examples of general arrangement are very rare and imperfect. To this deficiency of authorities it seems to be due that modern imitations of these ancient pavements have generally proved unsatisfactory in the resemblance, which they present to oil-cloth or carpeting; and the intention of producing richness of effect by carrying the ornamental design throughout the pavement without any intervening spaces has been wholly frustrated. Sufficient care has not been given to ascertain the ancient system of arrangement: it is, however, certain that a large proportion of plain tiles, black, white, or red, were introduced, and served to divide the various portions which composed the general design. Plain diagonal bands, for instance, arranged fret wise intervened between the compartments, or panels, of tiles ornamented with designs; the plain and the decorated quarries were laid alternately, or in some instances longitudinal bands were introduced in order to break that continuity of ornament which, being uniformly spread over a large surface, as in some modern pavements, produces a confused rather than a rich effect. It has been supposed, with much probability, that the more elaborate pavements were reserved for the decoration of the choir, the chancel, or immediate vicinity of an altar, while in the aisles or other parts of the church more simple pavements of plain tiles, black, white, or red, were usually employed. It may also deserve notice that in almost every instance when the ornamented tiles have been accidentally discovered or dug up on the site of a castle or mansion there has been reason to suppose a consecrated fabric had there existed, or that the tiles had belonged to that portion of the structure which had been devoted to religious services. We often meet with the item "Flanders tiles" in building-accounts of castles, but these were for the fireplace only. The lower rooms were usually "earthed," the upper rooms boarded. Parker, Gloss. of Architect. s.v.

Most of the tiles in England were made in the county of Worcester. Examples may be found in almost every parish church. Occasionally the patterns were alternately raised and sunk, so that the surface of the tiles was irregular. Examples of this sort were found at St. Alban's Abbey, and have been recently reproduced, and laid before the high-altar. From the 13th century to the 16th encaustic tiles were commonly used for the floors of churches and religious houses. Tiles have been used for wall-decoration, and for the adornment of tombs on the Continent; and this custom has likewise been restored in England. Since the manufacture of tiles has been carried out so efficiently in Worcestershire, their use has been common for all restored churches in that county. Modern specimens in some cases are remarkably fine, though sometimes wanting in that grace and character which were so remarkable in the old examples. —Lee, Gloss. of Liturg. Terams s.v.; Walcott, Sac. Archceöl. s.v.