"tarrel" in Hammett?

[Jesse Sheidlower]

In Dashiell Hammett's 1924 story "The Golden Horseshoe," first
published in _Black Mask_, a character (an Englishman) says:

  The hotel-sneak used to be my lay... I was rather good at it.
  I had the proper manner--the front. I could do the gentleman
  without sweating over it, you know.... I had a rather
  successful tour on my first American voyage. I visited most of
  the better hotels between New York and Seattle, and profited
  nicely. Then, one night in a Seattle hotel, I worked the
  tarrel and put myself into a room on the fourth floor. I had
  hardly closed the door behind me before another key was
  rattling in it....

Perhaps I'm missing an obvious dialect spelling or something,
but what is _tarrel_ in this passage? I can't find another
example of it anywhere, and it's not in the notes of the
Library of America edition of Hammett's stories.

Thanks.

Jesse Sheidlower
OED

------------------------------------------------------------
The American Dialect Society - http://www.americandialect.org