The art gallery that drifts above our heedless heads

I lay on the floor the other day, watching the evening clouds drift sedately in from the sea. Their undersides were pink or rosy, their upper parts grey or green, their shapes etiolated and fantastic. Below in the streets, people milled busily about, traffic streamed, yet up above, unregarded, all was calm, transcendent.

With what stealthy gradations the clouds transform themselves from shape to shape, from tint to tint. Some stay stationary, as if gazing down at us with incredulity; others skate urgently along.

Apparently, a Cloud Appreciation Society exists. And, apparently again, there are 10 genera of clouds, divided into 26 species and 31 varieties. (Luke Howard in 1803 first established the categories of cumulus, cirrus and nimbus.) It seems there is nothing on earth (or just above it) that scientists cannot categorise, quantify, and define. But as I lay watching the clouds, the last thing I wanted was to stick Latin names on them. I just wanted to merge with the great shifting spectacle, to let my imagination drift with these giant babyish apparitions.

There are days when it is worth watching the clouds, days when it is not. There are days when they seem the most ethereal entities on earth, strayed from some world of dream, and days when they are just cloudmass, oppressive occluders of the light.

In Aristophanes's play 'The Clouds', someone asks: 'In looking at the sky, have you never seen a cloud resemble a centaur, a leopard, a wolf or a bull?'

Shakespeare's Antony, before his suicide, compares himself to the evanescent clouds, noting 'sometimes we see a cloud that's dragonish, a vapour something like a bear or lion, a towered citadel, a pendent rock.'

Ralph Waldo Emerson speaks of 'the ultimate art gallery above'. Rupert Brooke in his sonnet 'Clouds' speaks of their 'noiseless tumult' and 'wise majestic melancholy train'. John Constable liked to sketch clouds. The mystical painter Cecil Collins claimed 'looking at a cloud will heal me very often of melancholy'.

Richard Jefferies, lying on Brighton beach in 1884, notes: 'I was always fond of watching clouds. In my pocket-book I have several notes about these peculiar sea-clouds. The value of these clouds lies in their slowness of movement and consequent effect in soothing the mind.'

But no-one, I think, matches Gerard Manley Hopkins, in his notebooks and poems, for elaborate descriptions of clouds. 'Eastward after sunset range of clouds rising in bulky heads moulded softly in tufts or bunches of snow,' he records in May 1866, while a student at Oxford. In July he sees 'multitudinous up-and-down crispy sparkling chains with pearly shadows up to the edges'.

By sunset, these have become 'level clouds naturally lead-coloured but the upper parts ruddled, some more, some less, rosy. Spits or beams braided or built in with pellet flakes made their way. Through such clouds anvil-shaped pink ones and up-blown fleece-of-wool flat-topped dangerous-looking pieces.'

In 1868, standing on a Swiss glacier, he notes 'prismatic colours in the clouds,' which are 'fine shapeless skins of fretted make, full of eyebrows or like linings of curled leaves'. In 1871 he sees clouds 'stepping one behind the other, their edges tossed with bright ravelling, as if white napkins were thrown up in the sun but not quite at the same moment'.

In 'Hurrahing in Harvest' (1877) he exclaims: 'What lovely behaviour of silk-sack clouds! Has wilder, wilful-wavier meal-drift moulded ever and melted across skies?' In another poem, he has: 'Cloud-puffball, torn tufts, tossed pillows flaunt forth, then chevy on an air-built thoroughfare: heaven-roisterers, in gay-gangs they throng; they glitter in marches.'