We believe that a good deal of the contrariety of opinion which prevails on this subject, arises from anglers and other men confounding an inclined plane with a perpendicular height.  Salmon will assuredly overcome a prodigious force of descending water,—­a roaring turmoil, which presents from below the aspect of a fall, but consists in reality of separate ledges massed together into one, when “floods lift up their voices.”  We are sorry to say, however, that the entire practice of angling is pervaded by a system of inaccuracy, exaggeration, and self-deceit, which is truly humiliating.  There is consequently no period in the life of a young person which ought to be more sedulously superintended by parents and guardians, than that in which he is first allowed to plant himself by the rivers of waters.  The most wonderful feature, however, in the leaping of salmon is not so much the height to which they spring, as the ease, elegance, and certainty, with which, while ascending small cataracts, they make their upward movements.  For example, near Oykel bridge in Sutherland, there is a rocky interruption to the more ordinary current of the river, where the water is contained, as it were, in stages of pots or little caldrons, over the lower edge of each of which it dances downwards in the form of a short perpendicular fall.  From a neighbouring bank by the river side, the movements of the aspiring fish may be distinctly seen.  When a grilse has made his way to the foot of one of these falls, (which he never could have ascended before, although he must have descended it in childhood on his seaward way,) without a moment’s doubt or hesitation he darts into the air, and throws himself head-foremost into the little basin above, to the bottom of which he instantly descends.  Nothing can be more curious than the air of nonchalance with which they drop into these watery chambers, as if they knew their dimensions to an inch, and had been in the habit of sleeping in them every night.  Now, from what has been ascertained of the natural history of the species, although the adult salmon of the Oykel must have previously made the leap at least once before, no fresh-run grilse could have ever done so; and yet, during suitable weather in the summer season, they are sometimes seen springing along with all the grace and agility of a troop of voltigeurs.  Their object of course is to rest themselves for a short time, before leaping into the second range from the ground floor.  But this innocent intention is too often interfered with; for a sharp-sighted Highlander, stationed on the bank above, immediately descends with landing-net in hand, and scoops them out of their natural caldron, with a view to their being speedily transferred to another of more artificial structure—­the chief difference, however, consisting in the higher temperature of the water.