If any reader wish to _feel_ the invisible making of the cloud that shall afterward rise on white wings or stream like a banner from mountain-bastions, let him stand on the slopes of a furrowed hill in this midsummer season. He will then feel the steady, upflowing tide of the warm air from the low-lying glens and valleys, a constant tepid draught, the breath of the earth. It will not be long before the current which shook yonder rose-flusht briar, which swayed these harebells as foam is blown, which lifted yonder rowan-branch and softly trampled this bracken underfoot, is gathered by scaur and sudden corrie to the sheer scarps of the mountain-summit, to be impelled thence, as a geyser is thrown from an imperious fount, high into the cold and windy solitude. There it may suddenly be transmuted to an incalculable host of invisible ice-needles, and become cirrus; to float like thistledown, or to be innumerably scattered in wisps and estrays, or long ‘grey-mares’-tails,’ or dispersed like foam among vast, turbulent shallows. Or it may keep to the lee-side of the mountain-summit, and stretch far like a serrated sword, or undulatingly extend like a wind-narrowed banner, covering as a flag the climbing armies of pine and boulder and the inscrutable array of shadow. _Cirrus_ ... what a beauty there is in the familiar name: what beauty of association for all who love the pageant of cloud, and, loving, know somewhat of the science of the meteorologist. It is not alone in this: memory and imagination are alike stirred by the names of the three other of the four main divisions of Cloud--the Cumulus, the Stratus, the Nimbus. From the grey and purple of earthward nimbus to the salmon-pink bastions of the towering cumuli, those unloosened mountains of the middle air, those shifting frontiers of the untravelled lands of heaven, and thence to the dazzling whiteness of the last frozen pinnacles of cirrus, all loveliness of colour may be found. Neither brush of painter nor word of poet can emulate those apparitions of gold and scarlet, of purple and emerald, of opal and saffron and rose. There every shade of dove-brown and willow-grey, every subterfuge of shadow and shine, can be seen.