How did led Zeppelin get their name?

If I remember correctly,Who drummer Keith Moon joked to them that their newly-formed band would go over "like a lead ballon". Years later,while touring Asia,the band was contacted by a descendent of the Von Hindenburghs,who had designed the zeppelin that crashed in the photo on their first album,and,just to shut her up,they played their Asian dates under a different name. I read it years ago,but the biography written by Steven Davis was an awesome read.