"The Obra del Consulado, as the opening cut is called, was concluded in the year 1789. It cost nearly a million of dollars; and the whole expense of the drainage from 1607 to the beginning of the present century, including the various projects commenced and abandoned when only partially executed,--the dykes connected with the _desague_,--and the two canals which communicate with the lakes of San Cristoval and Zumpango,--is estimated at six millions two hundred and forty-seven thousand six hundred and seventy dollars, or one million two hundred and forty-nine thousand five hundred and thirty-four pounds. It is supposed that one-third of this sum would have proved sufficient to cover all the expenses, had Martinez been furnished in the first instance with the means of executing his project upon the scale which he had judged necessary; for it is in the reduced dimensions of the gallery of Nochistongo, which was never equal to the volume of water to which at particular seasons it afforded an outlet, that all the subsequent expenditure has originated."[40] * * * * * We have judged it better to group together in this place all the facts relative to this most important national work,--so as to afford the reader a complete picture of the undertaking,--than to relate the slow and tedious history of the work as it advanced to completion during the reigns of many viceroys. The present condition of the _desague_ and its advantages will be treated in another portion of this work; and we shall therefore revert at once to the year 1609, in which a large number of negroes rebelled against the Spaniards. It seems that the blacks in the neighborhood of Cordova, who were in fact slaves on many of the _hiciendas_ or plantations, having been treated, in an inhuman manner by their owners, rose against them in great force, and gathering together in the adjacent mountains menaced their tyrannical task-masters with death, and their property with ruin. Velasco sent one hundred soldiers, one hundred volunteers, one hundred Indian archers, together with two hundred Spaniards and Mestizos, to attack them in their fastnesses. Several skirmishes took place between the slaves and these forces, and at length the negroes yielded to the Spaniards,--craving their pardon, inasmuch as their "insurrection was not against the king,"--and promising that they would no longer afford a refuge to the blacks who absconded from the plantations. Velasco at once granted their request, and permitted them to settle in the town of San Lorenzo.