Standing on the smooth sandy beach at the east end of the pond,in a calm September afternoon,when a slight haze makes the opposite shore-line indistinct,I have seen whence came the expression,“the glassy surface of a lake.”When you invert your head,it looks like a thread of finest gossamer stretched across the valley,and gleaming against the distant pine woods,separating one stratum of the atmosphere from another.You would think that you could walk dry under it to the opposite hills,and that the swallows which skim over might perch on it.Indeed,they sometimes dive below this line,as it were by mistake,and are undeceived.As you look over the pond westward you are obliged to employ both your hands to defend your eyes against the reflected as well as the true sun,for they are equally bright;and if,between the two,you survey its surface critically,it is literally as smooth as glass,except where the skater insects,at equal intervals scattered over its whole extent,by their motions in the sun produce the finest imaginable sparkle on it,or,perchance,a duck plumes itself,or,as I have said,a swallow skims so low as to touch it.It may be that in the distance a fish describes an arc of three or four feet in the air,and there is one bright flash where it emerges,and another where it strikes the water;sometimes the whole silvery arc is revealed;or here and there,perhaps,is a thistle-down floating on its surface,which the fishes dart at and so dimple it again.It is like molten glass cooled but not congealed,and the few motes in it are pure and beautiful like the imperfections in glass.You may often detect a yet smoother and darker water,separated from the rest as if by an invisible cobweb,boom of the water nymphs,resting on it.From a hilltop you can see a fish leap in almost any part;for not a pickerel or shiner picks an insect from this smooth surface but it manifestly disturbs the equilibrium of the whole lake.It is wonderful with what elaborateness this simple fact is advertised,-this piscine murder will out,-and from my distant perch I distinguish the circling undulations when they are a half a dozen rods in diameter.You can even detect a water-bug (Gyrinus)ceaselessly progressing over the smooth surface a quarter of a mile off;for they furrow the water slightly,making a conspicuous ripple bounded by two diverging lines,but the skaters glide over it without rippling it perceptibly.When the surface is considerably agitated there are no skaters nor water-bugs on it,but apparently,in calm days,they leave their havens and adventurously glide forth from the shore by short impulses till they completely cover it.It is a soothing employment,on one of those fine days in the fall when all the warmth of the sun is fully appreciated,to sit on a stump on such a height as this,overlooking the pond,and study the dimpling circles which are incessantly inscribed on its otherwise invisible surface amid the reflected skies and trees.Over this great expanse there is no disturbance but it is thus at once gently smoothed away and assuaged,as,when a vase of water is jarred,the trembling circles seek the shore and all is smooth again.Not a fish can leap or an insect fall on the pond but it is thus reported in circling dimples,in lines of beauty,as it were the constant welling up of its fountain,the gentle pulsing of its life,the heaving of its breast.The thrills of joy and thrills of pain are undistinguishable.How peaceful the phenomena of the lake!Again the works of man shine as in the spring.Ay,every leaf and twig and stone and cobweb sparkles now at mid-afternoon as when covered with dew in a spring morning.Every motion of an oar or an insect produces a flash of light;and if an oar falls,how sweet the echo!
In such a day,in September or October,Walden is a perfect forest mirror,set a round with stones as precious to my eye as if fewer or rarer.Nothing so fair,so pure,and at the same time so large,as a lake,perchance,lies on the surface of the earth.Sky water.It needs no fence.Nations come and go without defiling it.It is a mirror which no stone can crack,whose quicksilver will never wear off,whose gilding Nature continually repairs;no storms,no dust,can dim its surface ever fresh;-a mirror in which all impurity presented to it sinks,swept and dusted by the sun's hazy brush,-this the light dust-cloth,-which retains no breath that is breathed on it,but sends its own to float as clouds high above its surface,and be reflected in its bosom still.
A field of water betrays the spirit that is in the air.It is continually receiving new life and motion from above.It is intermediate in its nature between land and sky.On land only the grass and trees wave,but the water itself is rippled by the wind.I see where the breeze dashes across it by the streaks or flakes of light.It is remarkable that we can look down on its surface.We shall,perhaps,look down thus on the surface of air at length,and mark where a still subtler spirit sweeps over it.
