The great enterprise was carried through with extraordinary rapidity during his second tribunate. But the hastiness of the construction did not impair the beauty of the work. We are told that the roads ran straight and fair through the country districts, showing an even surface of quarried stone and tight-packed earth. Hollows were filled up, ravines and torrent beds were bridged, and mounting-blocks for horsemen lay at short and easy distances on both sides of the level course.[659] Although the initial expense of this construction may have borne heavily on the finances of the State, it is probable that the future maintenance of the roads was provided for in other ways. The commerce which they fostered may have paid its dues at toll-gates erected for the purpose:[660] and the ancient Roman device of creating a class of settlers on the line of a public road, for the purpose of keeping it in repair,[661] was probably extended. Road-making was often the complement of agrarian assignation,[662] and the two may have been employed concurrently by Gracchus. It was the custom to assign public land on the borders of a highway to settlers, the tenure of which was secured to them and their heirs on condition of keeping the road in due repair. Sometimes their own labour and that of their slaves were reckoned the equivalent of the usual dues; at other times the dues themselves were used by the public authorities for the purpose. Gracchus may thus have turned his agrarian law to an end which was not contemplated by that of Tiberius. The execution of the law must have been a heavy blow to the power and prestige of the senate. Its control of the purse was infringed and it ceased to be the sole employer of public labour. For Gracchus, in defiance of the principle that the author of a measure should not be its executant,[663] was his own road-maker, as his brother Tiberius had been his own land commissioner. He was the patron of the contractor and the benefactor of the Italian artisan. The bounties which he now gave were the reward of labour, and not subject to the criticism which had attended his earlier efforts for the relief of poverty in Rome; but some pretended to take the sinister view that the bands of workmen by which he was surrounded might be employed for a less innocent purpose than the making of roads.[664].