"compasses..."See in text(A Valediction: Forbidding Mourning)
Donne uses this simile to compare the lovers’ souls to the two legs of a compass. He is not talking about a traditional navigation tool here but rather a mathematical compass used to draw circles. The two feet of this compass are attached at the top, meaning even if they are apart, they are still connected and work as one unit.
"Like gold to airy thinness beat..."See in text(A Valediction: Forbidding Mourning)
Through simile, the speaker compares his love to the strength of gold, which when beaten, expands rather than breaks. By using this simile the speaker asserts that because their love is of the mind and soul, not the body, when he and his wife move physically apart, their love will not break but rather expand like beaten gold.