Hello there.
What rises yet never falls?
Smoke?
Do you have options so that i can see what we are dealing with lol
He uses that line to describe the birches themselves. Because when the girls are in that position air drying their hair, it is the same way that these trees bend in the strong wind.
Mary Shelley's Frankenstein is said to allude to the myth of Prometheus and the two long poems: Paradise Lost and The Rime of the Ancient Mariner.