Turning now to look back the other way, westward, he was surprised to see a second channel, which came almost to the foot of the hill on which he stood, but there ended and did not connect with the first.  The entrance to it was concealed, as he now saw, by an island, past which he must have sailed that afternoon.  This second or blind channel seemed more familiar to him than the flat and reedy shore at the mouth of the true strait, and he now recognised it as the one to which he had journeyed on foot through the forest.  He had not then struck the true strait at all; he had sat down and pondered beside this deceptive inlet thinking that it divided the mainlands.  From this discovery he saw how easy it was to be misled in such matters.

But it even more fully convinced him of the importance of this uninhabited and neglected place.  It seemed like a canal cut on purpose to supply a fort from the Lake in the rear with provisions and material, supposing access in front prevented by hostile fleets and armies.  A castle, if built near where he stood, would command the channel; arrows, indeed, could not be shot across, but vessels under the protection of the castle could dispute the passage, obstructed as it could be with floating booms.  An invader coming from the north must cross here; for many years past there had been a general feeling that some day such an attempt would be made.  Fortifications would be of incalculable value in repelling the hostile hordes and preventing their landing.

Who held this strait would possess the key of the Lake, and would be master of, or would at least hold the balance between, the kings and republics dotted along the coasts on either hand.  No vessel could pass without his permission.  It was the most patent illustration of the extremely local horizon, the contracted mental view of the petty kings and their statesmen, who were so concerned about the frontiers of their provinces, and frequently interfered and fought for a single palisaded estate or barony, yet were quite oblivious of the opportunity of empire open here to any who could seize it.

If the governor of such a castle as he imagined built upon the strait, had also vessels of war, they could lie in this second channel sheltered from all winds, and ready to sally forth and take an attacking force upon the flank.  While he pondered upon these advantages he could not conceal from himself that he had once sat down and dreamed beside this second inlet, thinking it to be the channel.  The doubt arose whether, if he was so easily misled in such a large, tangible, and purely physical matter, he might not be deceived also in his ideas; whether, if tested, they might not fail; whether the world was not right and he wrong.

The very clearness and many-sided character of his mind often hindered and even checked altogether the best founded of his impressions, the more especially when he, as it were, stood still and thought.  In reverie, the subtlety of his mind entangled him; in action, he was almost always right.  Action prompted his decision.  Descending from the hill he now took some refreshment, and then pushed out again in the canoe.  So powerful was the current in the narrowest part of the strait that it occupied him two hours in paddling as many miles.