What we must consider an unusual piece of good fortune has enabled us to present our readers, under this head, with a narrative of very remarkable character, and certainly of very deep interest. The Journal which follows not embodies a relation of the first successful attempt to cross the gigantic barriers of that immense chain of mountains which stretches from the Polar Sea in the north, to the Isthmus of Darien in the south, forming a craggy and snow-capped rampart throughout its whole course, but, what is of still greater importance, gives the particulars of a tour, beyond these mountains, through an immense extent of territory, which, at this day, is looked upon as totally untravelled and unknown, and which, in every map of the country to which we can obtain access, is marked as "an unexplored region." It is, moreover, the only unexplored region within the limits of the continent of North America. Such being the case, our friends will know how to pardon us for the slight amount of unction with which we have urged this Journal upon the public attention. For our own parts, we have found, in its perusal, a degree, and a species of interest such as no similar narrative ever inspired. Nor do we think that our relation to these papers, as the channel through which they will be first made known, has had more than a moderate influence in begetting this interest. We feel assured that all our readers will unite with us in thinking the adventures here recorded unusually entertaining and important.