Does nature present insurmountable engineering difficulties to the Panama scheme? By no means: for after the Croton aqueduct, our own railway tunnelling and the Britannia tubular bridge, engineering difficulties have become obsolete. Are the levels of the Pacific and the Gulph of Mexico, which should be joined, so different, that if one were admitted the fall would inundate the surrounding country? Not at all. Hear Humboldt on these points. Forty years ago he declared it to be his firm opinion that ‘the Isthmus of Panama is suited to the formation of an oceanic canal—one with fewer sluices than the Caledonian Canal—capable of affording an unimpeded passage, at all seasons of the year, to vessels of that class which sail between New York and Liverpool, and between Chili and California.’ In the recent edition of his ‘Views of Nature,’ he ‘sees no reason to alter the views he has always entertained on this subject.’ Engineers, both British and American, have confirmed this opinion by actual survey. As, then, combination of British skill, capital, and energy, with that of the most ‘go-ahead’ people upon earth, have been dormant, whence the secret of the delay? The answer at once allays astonishment:—Till the present time, the speculation would not have ‘paid.’ Large works of this nature, while they create an inconceivable development of commerce, must have a certain amount of a trading population to begin upon. A goldbeater can cover the effigy of a man on horseback with a sovereign; but he must have the sovereign first. It was not merely because the full power of the iron rail to facilitate the transition of heavy burdens had not been estimated, and because no Stephenson had constructed a ‘Rocket engine,’ that a railway with steam locomotives was not made from London to Liverpool before 1836. Until the intermediate traffic between these termini had swelled to a sufficient amount in quantity and value to bear reimbursement for establishing such a mode of conveyance, its execution would have been impossible, even though men had known how to set about it.