After an examination of the maps of Gisborne, Prevost, Strain, and Codazzi, there seems to be a general agreement in placing the summit of the ridge at not less than one thousand feet above the level of the tide. The united maps of Prevost and Gisborne exhibit their routes, proceeding from opposite points and intersecting, and the continuous profile between the two oceans fails to solve the question of a practicable route. As one of these parties had the advantage of Dr. Cullen’s personal guidance, it is but fair to allow him to supplement his first statement by an explanation of the causes which led to a failure so complete and unexpected. Speaking of the party from the Virago, he observes that Capt. Prevost “directed his explorations too far to the north-west.” That when it stopped he was but thirty miles from the point where the line should pass. Strain, on the other hand, erred by going “too far to the south-west.” In a word, the true line is to be found in the golden mean in which Aristotle places all virtue. But he has so far modified his first statement that he now thinks a line, “with tunneling,” may be found between Sucubti and Port Escocés. Under nine heads, he enumerates the advantages of this route. The reader has, perhaps, concluded that, like Pantagruel’s army, this subject is pretty well covered with tongue, and he may even adopt the conclusion of a distinguished attorney-general upon the fallibility of this unruly member. But one or two of the nine may be quoted. Under No. 7 Dr. Cullen states the land rises to nine hundred and thirty feet, and that here a tunnel will be required. No. 8 states that between this point and the Pacific no obstacle is to be found. The divide of one hundred and fifty feet, first discovered by Dr. Cullen, expanded to ten times that altitude. If men of intelligence and education can so err, all statements of persons whose previous habits and studies have not fitted them for passing judgment upon the relative merits of different canal routes should be received with caution. The failure of this formidable effort of four Governments to discover a practicable route for a ship canal between Caledonia Bay and the Gulf of San Miguel, while it disappointed reasonable expectation, stimulated public curiosity. The French, in nowise discouraged, determined to make another effort. The Granadian Minister, Francisco Martin, and Senator F. Barrow, signed, at Paris, a treaty embodying certain concession. According to agreement, the survey was to be conducted from the head of the Chuquanaqua toward the village of Monti, where Codazzi represented a summit of 460 feet.