But even if we suppose that no changes have taken place in this long lapse of time, there are, doubtless, between Long Island Sound and the eastern limit of Nova Scotia, a great number of rivers with all the characteristics of that described by the sagas. Precisely the same characteristics belong to the Taunton, the Charles, the Merrimack, the Piscataqua, the Kennebec, the Penobscot, the Saint Croix, and the St. John. All these rivers have one or more islands at their mouth, and there are abundant places near by where a ship might be stranded at low tide, and in each of these rivers there are expansions or bays from which they flow into the ocean.[6] And there are, probably, twenty other less important rivers on our coast, where the same conditions may likewise be found. What sagacious student of history, what experienced navigator, or what learned geographer has the audacity to say that he is able to tell us near which of these rivers the Northmen constructed their habitations, and made their temporary abode! The identification is plainly impossible. Nothing is more certain than the uncertainty that enters into all the local descriptions contained in the Icelandic sagas. In the numerous explorations of those early navigators, there is not a bay, a cape, a promontory, or a river, so clearly described, or so distinctly defined, that it can be identified with any bay, cape, promontory, or river on our coast. The verdict of history on this point is plain, and must stand. Imagination and fancy have their appropriate sphere, but their domain is fiction, and not fact; romance, and not history; and it is the duty of the historical student to hold them within the limits of their proper field. But there is yet another question which demands an answer. Did the Northmen leave on this continent any monuments or works which may serve as memorials of their abode here in the early part of the eleventh century? The sources of evidence on this point must be looked for in the sagas, or in remains which can be clearly traced to the Northmen as their undoubted authors. In the sagas, we are compelled to say, as much as we could desire it otherwise, that we have looked in vain for any such testimony. They contain no evidence, not an intimation, that the Northmen constructed any mason work, or even laid one stone upon another for any purpose whatever. Their dwellings, such as they were, were hastily thrown together, to serve only for a brief occupation. The rest of their time, according to the general tenor of the narrative, was exclusively devoted to exploration, and to the preparation and laying in of a cargo for their return voyage. This possible source of evidence yields therefore no testimony that the Scandinavians left any structures which have survived down to the present time, and can therefore be regarded as memorials of their abode in this country.