John Weeks Moore, Complete Encyclopaedia of Music… (1880)
“ Here he first devoted himself to the study of the clarinet. He remained here twenty years. In 1788 he visited Holland, Italy, and Russia, where his talent excited great admiration. In 1791 he gave a brilliant concert in Prague, then went to Hungary, and returned to Prague in 1792, at the coronation of the Emperor Francis Il., at which time his concerts created great enthusiasm. ”
