Chin deep in its middle you begin to feel that you know the pond. In a sense you are its eye and look upon the world as it does. Day breaks for the swimmer as it does for Walden, and the flash of the sun above the wood to eastward warms you both with the same sudden sweep of its August fire. In the same sense you are the pond’s ear and hear as it does. The morning rustle of the trees, shaking the dusk from their boughs, comes to you as a clear ecstasy, and you think you can hear the wan tinkling of the invisible feet of fairy mists as they leap sunward from the surface and vanish in the day. Over the wood comes the intermittent pulse of Concord waking, and by fainter reverberations the pond knows that Lincoln and more distant villages are astir. Then the first train of the day crashes by the southern margin and stuns the tympanum with a vast avalanche of uproar. To plunge beneath the surface and escape this is to learn the real color of the pond. From without, on the banks, this varies. Oftenest it is a dull, clear green like that of alexandrite, a chrysoberyl gem from the mines of Ceylon and the Ural mountains. You see this best from the higher points of the hills along the borders and at certain angles of the sun the green shows red reflections and tints of blue as does the gem. If, swimming in the center, you will tip up as a duck does and go head foremost with open eyes into the depths, you will see none of this color. There with all the influences of reflection and refraction eliminated you find yourself moving through an infinitely soft blue that is semi-opaque merely because a million generations of use has fitted the human eye for seeing details through air only. Yet the perception of color remains. Hold your breath desperately and swim as far down as you may and there is no change. The color has all the softness and gentle beauty of the turquoise. In certain lights among the Florida Keys I have seen this sweetest, gentlest of blues in the Gulf Stream, but in no other water. To turn and look at yourself in this water is to have another surprise. Already it seems as if the mystic fires of its depths had begun to inform you with a pure whiteness that should be akin to nobility of soul, and as you step forth on the shore mayhap this quality, passing subtly to the blood and brain, lingers for a while, and in the clear fire of renewed vitality you feel that the morning has indeed brought back to you the heroic age.