Celts, Etruscans, and Chinese made early and great advances in the art of using clay: the latter had even an imperial porcelain work at King-te-Ching, a hundred and eighty-four years Before Christ, and thirty years B.C. they introduced the same art into Japan. With regard to bricks and tiles we know that among Roman and mediæval builders bricks made of clay were held in high estimation. The former enterprising people having penetrated into our valleys and excavated our hill sides in search of lead and iron were not likely to neglect the clays with which the ore for the latter was associated; and evidences of the extent to which they worked them on the banks of rivers, where such seams were exposed, particularly on the banks of those flowing through the great centres of their occupation, confirms this view. Their armies were accompanied by men learned in the art; and in the relics dug up at Malmesbury, Salisbury, Romsey, Malvern, and Uriconium, modern workers in clay may learn much of the early history of their craft. The still upstanding walls at Wroxeter, with string courses of tiles, and the numerous specimens of bricks, tesseræ, and pottery in different coloured clays, brought to light by excavations within its shadow, are interesting from the fact that some are supposed to have been manufactured from clays still in use in the neighbourhood. At Caersws, a little village on the banks of the Severn, between Llandinam and Newtown, well made bricks, both of composite and simple clay, may be seen stamped with Roman letters, probably the initials of workmen’s names; and, as a test of the durability of both, it may be remarked that after having done duty in buildings in which the Roman masons placed them, they have been rebuilt by British workmen into the chimneys of the village. These, of course were burnt; but, favoured by the extreme dryness and heat of their own climate, the Romans, like the Egyptians, used clay mixed with chopped straw, to assist the tenacity of their bricks, which, without being at all artificially heated, have lasted thousands of years. The material of which Roman bricks in this country were formed was usually a strong clay, such as brickmakers call tile-clay; well tempered, well pressed, and well burnt, producing a heavy tough brick, indefinitely durable, and of a good deep-red colour.