So in the Tempest, Ariel is the spirit of the air and Caliban of the earth, ministering, with more or less of unwillingness, to man's necessities.

to your charge repair; The fluttering fan be Zephyretta's care; The drops to thee, Brillante, we consign; And, Momentilla, let the watch be thine; Do thou, Crispissa, tend her favourite lock; Ariel himself shall be the guard of Shock.