But Winckelmann rendered a great service to art by founding a method of study which was soon applied by Zoëga[6] and by Ennio Quirino Visconti,[7] to the description of the works which filled public and private galleries, or were being continually discovered by excavation. These two _savants_ classified a vast quantity of facts; thanks to their incessant labours, the lines of the master's rough sketch were accented and corrected at more than one point; the divisions which he had introduced into his picture were marked with greater precision; the groups which he had begun to form were rendered more coherent and compact; their features became more precise, more distinct, and more expressive. This progress was continuous, but after the great wars of the Revolution and the Empire its march became much more rapid, and the long peace which saw the growth of so rich a harvest of talent, was also marked by a great increase in the energy with which all kinds of historical studies were prosecuted. [6] Zoëga busied himself greatly with Egypt, and in inaugurating the study of Coptic prepared the way for Champollion. But the work which gave him a place among the chief scholars of Winckelmann is unfinished; the _Bassirilievi antichi di Roma_ (Rome, 2 vols. 4to. 1808) only contains the monuments in the Villa Albani, engraved by Piroli, with the help of the celebrated Piranesi. A volume containing most of his essays was given to the world by Welcker in 1817 (_Abhandlungen herausgegeben und mit Zusätzen begleitet_, 8vo. Göttingen), who also published his life and a volume of his correspondence (Zoëga, _Sammlung seiner Briefe und Beurtheilung seiner Werke_, 2 vols. 8vo. Stuttgart, 1819). [7] _Il Museo Pio-Clementino_, Visconti, vol. i. 1782; by Enn. Quir. Visconti, vols. ii. to vii. Rome, 1784-1807. _Museum Worsleyanum_, 2 vols. folio. London, 1794. _Monumenti Gabini della Villa Pinciana_, Visconti, 8vo. 1797. _Description des Antiques du Musée Royal_, begun by Visconti and continued by the Comte de Clarac. 12mo. Paris, 1820. For the collection of the materials and the execution of the plates in the _Iconographie Grecque et Romain_, Visconti took advantage of his opportunities as director of the _Musée Napoléon_, into which the art treasures of all Europe, except England, were collected at the beginning of this century.