The cloud brings rain, moisture, hail, and snow, and gives shade. It is infused with electricity which acts as its guide in the form of lightning accompanied by thunder. When the cloud covers the rising sun, it causes its beams to be spread out over the sky. At evening the cloud floats over the setting sun like a bird; at night, the cloud provides a thin covering for the moon. Where the cloud cover is removed by the wind, the moon and stars are reflected in the earth's bodies of water.
The cloud under certain conditions forms a ring around the sun and the moon. During storms the cloud spreads across the sky like a roof. At other times the rainbow acts as an arch of triumph for the cloud to march under. The cloud, formed in the sky, draws its substance from the earth and water below it and is part of a never-ending cycle in which it alternately disappears and reappears.
In "The Cloud," Shelley is again the myth-maker. The cloud is not merely a physical substance but seems to be an immortal minor divinity (such as a naiad or a Nereid, which in classical mythology were associated with water). By employing this form of personification, Shelley is able to endow nature with the powers and attributes of immortals. Thus his cloud is not only capable of changing its form almost at will but is incapable of dying as well: "I change, but I cannot die."
Shelley's cloud is almost bewilderingly multiform. It begins as a gardener watering flowers, changes to a mother or nurse shading a child from the midday sun while the child takes a nap, becomes a bird that shakes dew from its wings to awaken the buds (which are babies rocked to rest on the breast of their mother the earth), and becomes a thresher wielding a flail. It laughs, sifts, sleeps, folds its wings like a bird, puts a girdle around the sun, becomes a roof, marches through a triumphal arch, is a baby daughter, passes "through the pores of the ocean and shores," and tears down an empty tomb. As a divinity, it can be and do a multiplicity of things. Shelley's "The Cloud" is compact with images, which, taken together, give the reader a good account of this natural phenomenon in the language of poetry.
Shelley's "Cloud," although extraordinarily rich in changing imagery, presents no special difficulty except perhaps in the second stanza, in which he makes lightning the pilot of the cloud. What Shelley is saying is that atmospheric electricity or lightning is formed in the tiny droplets of vapor that make up the clouds. He is merely asserting a familiar fact.
In addition to making lightning the guide of the cloud, Shelley subordinates the lightning to some force in the earth which attracts it. He has his cloud say:
Over earth and ocean, with gentle motion,
This pilot is guiding me,
Lured by the love of the genii that move
In the depths of the purple sea;
Over the rills, and the crags, and the hills,
Over the lakes and the plains,
Wherever he dream, under mountain or stream,
The Spirit he loves remains.
Shelley's genii are Moslem spirits that inhabit the earth and exercise supernatural power. Erasmus Darwin, an eighteenth-century poet-scientist, had used the word metaphorically in his Botanic Garden, where Shelley probably found it. The Spirit whom the lightning loves seems to be the genii in a singular form, but Shelley is not very clear here. He may have changed from the plural to the singular for the sake of a needed rime: remains. The genii are probably meant to poetically present the theory of atmospheric electricity, drawn by the sun from the earth as water vapor, returning to the earth as lightning, dew, frost, and rain. Shelley's genii therefore represents the phenomenon that when an electrically charged cloud approaches the earth's surface, an opposite charge is induced in the earth's surface. When there exists sufficient electrical potential, a lightning flash occurs. Shelley's knowledge of atmospheric electricity, al-though expressed in highly figurative language, is nevertheless accurate.