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. Needless to say, the cloud of a thunderous summer is the most beautiful of all. It has spaces of a grey for which there is no name, and no other cloud looks over at a vanishing sun from such heights of blue air. The shower-cloud, too, with its thin edges, comes across the sky with so influential a flight that no ship going out to sea can be better worth watching. The dullest thing perhaps in the London streets is that people take their rain there without knowing anything of the cloud that drops it. It is merely rain, and means wetness. The shower-cloud there has limits of time, but no limits of form, and no history whatever. It has not come from the clear edge of the plain to the south, and will not shoulder anon the hill to the north. The rain, for this city, hardly comes or goes; it does but begin and stop. No one looks after it on the path of its retreat. SHADOWS