What metaphors are used in A Valediction: Forbidden Mourning by John Donne?

A metaphysical conceit is an extended metaphor or simile in which the poet draws an ingenious comparison between two very unlike objects. "A Valediction: Forbidding Mourning" ends with one of Donne's most famous metaphysical conceits, in which he argues for the lovers' closeness by comparing their two souls to the feet of a drawing compass—a simile that would not typically occur to a poet writing about his love!