A Rare and Unusual Pair of Gueridons with 12th Century Roman Porphyry and Intricate Geometric Intarsia Parquetry Marble Tops, once part of a Roman villa floor created by the Cosmati family, with porphyry centers surrounded by geometric patterns of specimen marbles, now raised on Napoleon III tripartite ebonized iron bases with gilded ormolu busts, rosettes and lion paw feet and connected by a circular conforming perimeter stretcher