I can't be sure, but I think a "meal man" is someone who sells corn or other meal.

• Text:
  

An ingenious cheat was recently executed
upon one of the city meal men in Boston. He
was induced by a by-stander to try his luck at
the bowling alley, from whom he won a few dol-
lars, which was intended no doubt as a lure. --
He was then about to retire, but was induced
to play longer upon large odds being offered by
his antagonist upon the spare ball, and was fleec-
ed of about $130. It afterwards appeared that
the pins had lines attached to them, by which
the fellows employed in setting them up for the
players, could pull them down so as to win the
bet at their pleasure, and without being detect-
ed. The winner was not however permitted
to enjoy the fruits of his ingenuity, but was pur-
sued and lodged in jail.