When I Heard the Learn'd Astronomer Steaminess Rating

Exactly how steamy is this poem?

PG

Leave it to Whitman to write a sexy poem without using overtly sexual language. The first half has us squirming in our seats in the lecture hall. In the second half, he takes us into the "mystical moist night-air," and we can't help but think of all kinds of Freudian connections to the womb and "Mother" Nature. Still, we've got to give this one a "PG," because Whitman is just so darned good at hiding any underlying steaminess.