Twain used a Smith & Todd gold-nibbed pen dated 1868 (I own Twain's Smith &
Todd pen). In the 1880s he used a Paul Wirt dropper pen and wrote admiringly
of its smooth writing qualities which they used in their advertising. He
later used a Conklin fountain pen whose filling lever projected slightly
from the body of the pen and kept it from rolling off a desk, and they used
his endorsement in their ads as well. I have advertising from at least one
other pen-maker who claimed Twain used their pens, but their name escapes me
at the moment. Conklin, still in business, has made new "Mark Twain" pens to
celebrate their connection with Twain, although I don't know if the model
they have reproduced is solidly documented as the very model Twain actually
used.

Kevin Mac Donnell
Austin TX