During the time of the French Revolution the manufactory was in a critical state of existence, but was still kept in a working state. In the year 1800 Alexandre Brongniart was appointed director, a post he held for forty-seven years—and after his appointment the manufacture of soft porcelain ceased. In his time the manufactory was in a state of great prosperity, and the science he brought to bear on the manufacturing processes was of immense importance. Vases over seven feet in height were produced, and the pieces which were made were ornamented with trophies and battle scenes that glorified the events in the reign of Napoleon I. In the reign of Louis Philippe the artists Fragonard, Chenavard, Clerget, and Julienne introduced a new style of Renaissance decoration and design, but this was of a heavy and overloaded order that was not exactly suited to the character of porcelain. About the middle of the present century Louis Robert, the chief painter at Sèvres, introduced the novelty of _coloured pastes_, which was to develop later into the _pâte-sur-pâte_ process, so successfully practised by the talented M. Solon, who has executed so much of this beautiful work for Minton’s in England. The process of Louis Robert consisted in the use of porcelain paste coloured with oxides. A _barbotine_ or _slip_ was made of this composition and paintings were executed with it in slight relief, the white paste being used chiefly on a coloured ground, the modelling or light and shade being regulated according to the thickness of the semi-transparent material employed. When finished this kind of work has a cameo-like effect. GERMAN POTTERY. German stoneware was manufactured at an early date, and in the countries bordering upon the Rhine the industry must have been in an active state in the fifteenth and sixteenth centuries, judging from the plentiful examples of the different varieties of the ware formerly known as “Grès Flamands” or “Grès de Flandres,” but now classified under their proper German origins. In the sixteenth century this ware was carried in great quantities from Raeren, from Frechen and Sieburg, near Cologne, and from Greuzhausen, near Coblentz, down the Rhine to Leyden and the Low Countries. [Illustration: Fig. 64.—Delft Vase.] The brown stoneware of Raeren—which formerly belonged to the ancient Duchy of Limbourg—was especially in great request in Flanders. This brown ware was of a spherical or cylindrical shape, divided by a central broad band, with decorations of figure subjects, shields, masks, arms, &c.; the neck is also decorated with shields and bosses, and the foot with rings and guilloche ornament. Some good specimens of blue stoneware—called the “blue of Leipzig”—were also made at Raeren.