The neighbouring lake, known to the ancients as Lacus Fucinus, had till the beginning of this century an area of 37,990 acres, and was remarkable for its frequent changes of level. As early as the 1st century, the Emperor Claudius constructed a subterranean passage by which the surplus waters found an outlet to the Liris or Garigliano. No fewer than 30,000 workmen were employed for a space of eleven years; and the undertaking seems to have been as successful as it was bold. But in the following reign the passage was allowed to fall into disrepair; and it has been reserved to the present generation to see the old Roman works not only restored but surpassed. From 1793 to 1810 the lake had been gradually rising till it was 30 feet above its former level; and the attention of the Neapolitan Government was directed to the danger. Little, however, was effected till 1852, when the necessary works were undertaken by a company, under the direction of Mr C. Hutton Gregory, who proceeded to widen the emissarium and support the walls with arched work. The shares of the company were gradually bought up by Prince Giulio Torlonia of Rome, who successfully carried on the operations at his own expense till his death in 1871. About 36,000 acres of rich arable land have been reclaimed, and the com-crops yield a profit of from 30 to 36 per cent The new tunnel is about four miles long, and has a cross section of 21 square yards. The honour of the engineering has been shared by Montricher, who died in 1858, Bermont, and Brisse. See Kramer, Der Fucìner See, Berlin, 1839.