Mark Twain

designed by [[Lobsang}] and the Black Corporation, and piloted by Lobsang, Joshua Valienté with the help of Shi-Mi, the Mark Twain was a dirigible airship designed to sail through the infinity of long Earths, recording and measuring what could be found there.

It very nearly foundered in the unexpected Gap but lived to tell the tale, despite suffering severe damage. all subsequent models, called twains in honour of the first in line, are now routinely built to be able to withstand at least temporary exposure to deep space and can step through worlds far faster.