But in the sky of “sunny Alps” of clouds the sight goes farther, with conscious flight, than it could ever have journeyed otherwise.  Man would not have known distance veritably without the clouds.  There are mountains indeed, precipices and deeps, to which those of the earth are pigmy.  Yet the sky-heights, being so far off, are not overpowering by disproportion, like some futile building fatuously made too big for the human measure.  The cloud in its majestic place composes with a little Perugino tree.  For you stand or stray in the futile building, while the cloud is no mansion for man, and out of reach of his limitations.

The cloud, moreover, controls the sun, not merely by keeping the custody of his rays, but by becoming the counsellor of his temper.  The cloud veils an angry sun, or, more terribly, lets fly an angry ray, suddenly bright upon tree and tower, with iron-grey storm for a background.  Or when anger had but threatened, the cloud reveals him, gentle beyond hope.  It makes peace, constantly, just before sunset.

It is in the confidence of the winds, and wears their colours.  There is a heavenly game, on south-west wind days, when the clouds are bowled by a breeze from behind the evening.  They are round and brilliant, and come leaping up from the horizon for hours.  This is a frolic and haphazard sky.

All unlike this is the sky that has a centre, and stands composed about it.  As the clouds marshalled the earthly mountains, so the clouds in turn are now ranged.  The tops of all the celestial Andes aloft are swept at once by a single ray, warmed with a single colour.  Promontory after league-long promontory of a stiller Mediterranean in the sky is called out of mist and grey by the same finger.  The cloudland is very great, but a sunbeam makes all its nations and continents sudden with light.

All this is for the untravelled.  All the winds bring him this scenery.  It is only in London, for part of the autumn and part of the winter, that the unnatural smoke-fog comes between.  And for many and many a day no London eye can see the horizon, or the first threat of the cloud like a man’s hand.  There never was a great painter who had not exquisite horizons, and if Corot and Crome were right, the Londoner loses a great thing.

He loses the coming of the cloud, and when it is high in air he loses its shape.  A cloud-lover is not content to see a snowy and rosy head piling into the top of the heavens; he wants to see the base and the altitude.  The perspective of a cloud is a great part of its design—­whether it lies so that you can look along the immense horizontal distances of its floor, or whether it rears so upright a pillar that you look up its mountain steeps in the sky as you look at the rising heights of a mountain that stands, with you, on the earth.

The cloud has a name suggesting darkness; nevertheless, it is not merely the guardian of the sun’s rays and their director.  It is the sun’s treasurer; it holds the light that the world has lost.  We talk of sunshine and moonshine, but not of cloud-shine, which is yet one of the illuminations of our skies.  A shining cloud is one of the most majestic of all secondary lights.  If the reflecting moon is the bride, this is the friend of the bridegroom.