In various executed works of the decades preceding the French Revolution it is possible to trace the gradual emergence of mature Romantic Classicism in France, as also to some extent in the executed buildings and, above all, the projects of the younger George Dance (1741-1825)[12] in England. But it is in the extraordinary designs, dating from the eighties, by two French architects a good deal younger than Soufflot that the new ideals were most boldly and completely visualized. In the last twenty-five years these two men, L.-E. Boullée (1728-99) and C.-N. Ledoux (1736-1806), have increasingly been recognized as the first great masters of Romantic Classical _design_ if not, in the fullest sense, the first great Romantic Classical _architects_. Boullée built little and few of his projects and none of the manuscript of his book on architecture, both now preserved at the Bibliothèque Nationale, were published—or at least not until modern times.[13] Yet they must have been well known to his many pupils—including J.-N.-L. Durand, who was the author of the most influential architectural treatise of the Empire period, and doubtless to others as well (see Chapters 2 and 3). Ledoux was from the first a very successful architect, working with assurance and considerable versatility in the _style Louis XVI_ from the late sixties, particularly for Mme du Barry. He became an academician and _architecte du roi_ in 1773 and spent the next few years at Cassel in Germany. His major executed works are in France, however, and belong to the late seventies and eighties. These are the Besançon Theatre of 1775-84, the buildings of the Royal Saltworks at Arc-et-Senans near there of 1775-9—he had been made _inspecteur_ of the establishment in 1771—and the _barrières_ or toll-houses of Paris, which were built in 1784-9 just before the Revolution. In this later work most of the major qualities of his personal style, qualities carried to much greater extremes in his projects, are readily recognizable; his earlier work was of rather transitional character and not at all unlike what many other French architects of his generation were producing.