A PAIR OF RUSSIAN IMPERIAL PORCELAIN CENTERPIECES, IMPERIAL PORCELAIN FACTORY, PERIOD OF NICHOLAS I (1825-1855) the turquoise interior of each decorated with vegetative motifs and three naturalistically painted cartouches of royal residencies and institutions(one featuring the Pulkovo Observatory, Pavlovsk Palace, Church of Transfiguration; the other the Oranienbaum, Peterhoff, the Kamenny Islands Palaces), separated by gilt medallions with female faces, with everted gilt rims, each on a single fluted foot with acanthus leaf decorations, Imperial Glass manufactory, cypher of Tsar Nicholas II on base; height of each: 27 cm (10 5/8 in.)