Taken with their context, the words seem to be an illustration of the greater equality of day and night referred to in the opening words of the sentence. Their real value lies in the fact that they embody a remark of a circumstantial and business-like character, which goes far to support the historical authenticity of the narrative. It is not the sort of thing that a romancer would invent, it is the sort of thing that a traveller would notice. Secondarily, though in all probability the words indicate a much more southerly latitude, they make it impossible that the site of the observation was north of (roughly) 49°. To consider them as a deliberate attempt to fix latitude is to lose sight of all probabilities. Let any who still adhere to this interpretation go and fix marks for themselves, and endeavour therefrom to ascertain the latitude. The south point could of course be fixed accurately, by the place of the shortest shadow or various other well-known devices. The time equivalents given by Henderson and Troil do not, however, suggest that it was so fixed as a rule. But without instruments to measure the angles for the other marks correctly to—say—2° would be very difficult indeed, while the marks themselves would probably subtend an appreciable angle. An error of one degree will be more than reproduced in the latitude. Any change in the exact position of the observer would be likely to cause an inaccuracy of at least this extent; so that if the locality visited is to be identified at all it certainly will not be by the use of this passage, on which so many commentators have expended so much fruitless ingenuity. VI. THE VOYAGES. GENERAL CONSIDERATIONS The reader who has attentively followed the argument so far will, I think, be convinced that the discovery and exploration of some parts of America by the Norsemen rests upon a solid historical foundation. It now becomes necessary to deal with a matter as to which there is considerably more scope for controversy; the reconstruction, so far as is reasonably possible, of the voyages themselves. No one acquainted with the difficulties presented by the records of far later explorers, such as Cabot and Corte Real, will expect this to be a subject on which it is possible to dogmatize; the geographical details can probably never be settled with absolute finality. We must advance cautiously and by stages, eliminating the impossible and establishing broad lines, before we embark on the fascinating task of theorizing on points of detail. _Difficulties of the Task._