projects were not required; but the Mulvian bridge (Ponte Molle), by which the Flaminian road crossed the Tiber not far from Rome, was in 645 reconstructed of stone.  Lastly in Northern Italy, which hitherto had possessed no other artificial road than the Flaminio-Aemilian terminating at Placentia, the great Postumian road was constructed in 606, which led from Genua by way of Dertona, where probably a colony was founded at the same time, and onward by way of Placentia, where it joined the Flaminio-Aemilian road, and of Cremona and Verona to Aquileia, and thus connected the Tyrrhenian and Adriatic seas; to which was added the communication established in 645 by Marcus Aemilius Scaurus between Luna and Genua, which connected the Postumian road directly with Rome.  Gaius Gracchus exerted himself in another way for the improvement of the Italian roads.  He secured the due repair of the great rural roads by assigning, on occasion of his distribution of lands, pieces of ground alongside of the roads, to which was attached the obligation of keeping them in repair as an heritable burden.  To him, moreover, or at any rate to the allotment-commission, the custom of erecting milestones appears to be traceable, as well as that of marking the limits of fields by regular boundary-stones.  Lastly he provided for good -viae vicinales-, with the view of thereby promoting agriculture.  But of still greater moment was the construction of the imperial highways in the provinces, which beyond doubt began in this epoch.  The Domitian highway after long preparations(16) furnished a secure land-route from Italy to Spain, and was closely connected with the founding of Aquae Sextiae and Narbo;(17) the Gabinian(18) and the Egnatian (19) led from the principal places on the east coast of the Adriatic sea—­the former from Salona, the latter from Apollonia and Dyrrhachium—­into the interior; the network of roads laid out by Manius Aquillius immediately after the erection of the Asiatic province in 625 led from the capital Ephesus in different directions towards the frontier.  Of the origin of these works no mention is to be found in the fragmentary tradition of this epoch, but they were nevertheless undoubtedly connected with the consolidation of the Roman rule in Gaul, Dalmatia, Macedonia, and Asia Minor, and came to be of the greatest importance for the centralization of the state and the civilizing of the subjugated barbarian districts.

In Italy at least great works of drainage were prosecuted as well as the formation of roads.  In 594 the drying of the Pomptine marshes—­a vital matter for Central Italy—­was set about with great energy and at least temporary success; in 645 the draining of the low-lying lands between Parma and Placentia was effected in connection with the construction of the north Italian highway.  Moreover, the government did much for the Roman aqueducts, as indispensable for the health and comfort of the capital as they were costly.  Not only were the two that