Rosas had continued to triumph over all the forces which the Republic had united to free itself from his horrible tyranny, and the Unitario chiefs and emigrants were driven into Montevideo, where Rosas besieged them. In 1848, while still in Chili, Colonel Sarmiento established a periodical called "The Cronica," and advocated a federal government, like that of the United States, as the only means of continuing the Republic. In this manner he could attract the provinces to their party, accepting the federation, which existed, in fact. After he had established that semi-annual periodical, he founded another weekly one, called "Sud America," which lasted till 1850, in which he unfolded the constituent principles of federation, and promoted the free navigation of the rivers in order to give seaports to the provinces. Another object of it was to encourage emigration. His endeavors were crowned with the most complete success. In 1850, he wrote a pamphlet proposing a Congress, and preparing the way to form a union and alliance of the Unitario chiefs and the Federal caudillos. This pamphlet was called "Argiropolis," and his plan was to found another capital in the island of Martin Garcia. This pamphlet was very effective, and ruined Rosas among his own supporters. Bompland, the celebrated naturalist, the companion of Humboldt, presented himself before Urquiza, the principal chieftain under Rosas, and refused obedi-
