From Nicaragua we learn that the survey of the route from Lake Nicaragua to the Pacific is nearly completed. The distance is 12 miles, and the highest point only 40 feet. The steamer Director is running on the lake. A complete steam communication will in a few weeks be effected between the lake and the Atlantic; a canal of 12 miles will unite the lake with the Pacific. When lines of steamers are established on both sides of the Isthmus, connecting with this rout across, it is anticipated that the passage from New York to San Francisco may be made in 24 days. Carthagena was visited on the 7th of February by a severe shock of an earthquake, which lasted nine seconds. Considerable damage was done throughout the city; some houses were thrown down, and several lives lost. The city walls and the Cathedral were much injured. Had the shock been protracted a few seconds longer, the whole city would have been laid in ruins. On the night of the 8th the public squares and walks were filled with people who had left their dwellings in dread of a repetition of the shock. But up to the 15th none had occurred. No city in the region felt the shock so severely as did Carthagena. In Peru, Congress was to meet March 20. The Presidential election has terminated in favor of Echenique. In Bolivia there have been one or two attempts at insurrection. A decree has been issued, banishing all Buenos Ayreans except those married to Bolivian women, and all who were known as Federalists. From Brazil it is officially announced that liberated slaves, not Brazilian born, must not be taken to that country. By a law of 1831, which it is announced will be rigidly enforced, a penalty of 100 milreas, besides expenses of re-exportation, is imposed upon masters of vessels for each such person landed. GREAT BRITAIN. We have the somewhat unexpected intelligence of the defeat and resignation of the Whig Ministry at the very opening of the session. Parliament met on the 4th of February. On the preceding evening, the customary absurd farce of searching the vaults under the house, as a precaution against a second gunpowder-plot, was enacted. Nothing was discovered boding any peril to the wisdom of the nation about to be assembled. The Royal Speech was of the usual brevity, and of more than usual tameness. The following were the only paragraphs of the least interest: "I have to lament, however, the difficulties which are still felt by that important body among my people who are owners and occupiers of land. But it is my confident hope, that the prosperous condition of other classes of my subjects will have a favorable effect in diminishing those difficulties, and promoting the interests of agriculture.