the Hurlothrumbo was Emperor Norton’s steamship. Who was Emperor Norton? Why, he was the Emperor of the United States and Protector of Mexico. What? You never heard tell of the fella?
This site will help, a bit.
A big TYVM to Richard Gillman’s Absolute Piffle.
(Updated with archive.org link February 2013, it seems the Clampers behind hurlothrumbo.org let the domain lapse.)