Lieut. T. A. Craven, U. S. N, has made a report in reference to the practibility of an inter-oceanic communication from the gulf of Darien to the Pacific ocean, by the Atrato and Troando rivers, in which, after giving full details of his late survey, he thus briefly sums up the actual physical difficulties to be overcome in cutting the proposed canal :?— " 1. A cut through some five miles of submerged mud at the mouth of the river, with the prospective certainty of constant dredging to keep it open. 2. The Herculean labor and incalculable expense of cutting through the lagoons of the Truando, and the embedded logs of the Paios Caides, where the whole country is inundated during at least nine months of the year, and where the floods of a day may destroy the work of a week. 8. The vast expense attending the removal of basaltic rock, in a country where labor and provisions must all be imported at most extravagant rates. 4. The want of an anchorage on the Pacific coast. 5. The fatal effects of the climate, which, it may be safely estimated, will disable at least one-third of any force that may be sent there. You will not be surprised that, with the preceding arguments, I am of the opinion that the proposed oanal is impracticable, as involving an expenditure of treasure not easily estimated, and a sacrifice of life from which the stoutest heart may shrink. Human perseverance and ingenuity mar, it is true, overcome the obstacles enumerated; but at least two generations must pass away ere the world can realize the accomplishment of a much less extensive work than that contemplated."