Answer:
I fly through the air on small feathered wings, seeking out life and destroying all things.
What I am filled, I can point the way. When I am empty. Nothing moves me. I have two skins. One without and one within.
They can be harbored, but few hold water. You can nurse them, but only by holding them against someone else. You can carry them, but not with your arms. You can bury them, but not in the earth.
What 8 letter word can have a letter taken away and it still makes a word. Take another letter away and it still makes a word. Keep on doing that until you have one letter left. What is the word?
Five hundred begins it, five hundred ends it. Five in the middle is seen. First of all figures, the first of all letters. Take up their stations between. Join all together, and then you will bring before you the name of an eminent king.
What is always coming but never arrives?