The tiles which bear the name of their inventor, Francesco Niculoso Pisano the Italian, who lived and worked for many years at Seville, date from about the same time as the "cuenca" _azulejos_. In the case of the _Pisano_ tile, there is no indentation caused by the imprint of a mould, the surface being merely coated with a monochrome glaze, painted upon and fired, the decoration thus remaining flat all over. Commonly the ground is white or yellow, with the colour of the pattern shaded blue, or black, or deepish purple. This process, which lent itself to most elaborate and effective schemes of ornament, remained in vogue until the eighteenth century, and was practised, not only by Pisano himself, but by a long succession of his pupils, followers, and imitators. [Illustration: LIII ANDALUSIAN NON-LUSTRED WARE (_A.D. 1480-1495. Osma Collection_)] Such were the processes in use among the _azulejo_-makers of old Seville. Specimens of their craftsmanship which yet survive and illustrate the various styles and epochs may be thus enumerated:-- (1) Mosaic tile-work, such as appears in Seville at the time of the Almohade invasion. A fragment of this kind of work forms part of the collection of Señor Osma, and proceeds from the church of San Andrés. Tiles and smaller pieces of mosaic-work, coloured in malachite green and white, were also found in 1899 and 1900, in the upper walls of the renowned Torre del Oro, or "Golden Tower," erected in the year 1220, and which is popularly thought to derive its venerable title from the sparkle of the sun upon its _azulejos_. Another piece of primitive mosaic, measuring rather less than a yard square, and containing star-shaped geometrical devices, was found in 1890 beneath the floor of the cathedral; while mosaics of a later age, including the more elaborate _lacería_ patterns that resemble ribbon, are preserved in the Patio de las Doncellas of the Alcázar, in the Casa de Olea, and in the parish churches of San Estéban, San Gil, and Omnium Sanctorum.