"compliments of the season" by o henry. -----------------------In "Pigeon" McCarthy's pocket was a section of one-inch gas-pipe eight inches long. In one end of it and in the middle of it was a...

"compliments of the season" by o henry.

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In "Pigeon" McCarthy's pocket was a section of one-inch gas-pipe eight inches long. In one end of it and in the middle of it was a lead plug. One-half of it was packed tight with solder. Black Riley carried a slung-shot, being a conventional thug. "One-ear" Mike relied upon a pair of brass knucks--an heirloom in the family. ------------------------ How are "brass knucks" and "heirloom" related?
Expert Answers
pohnpei397 eNotes educator| Certified Educator

In putting these two things together, the author is trying to tell us in a humorous way that One-ear Mike is a criminal and that he has come from a family of criminals.

Brass knuckles are, of course, used mainly by criminals.  There is not much of a legal use for something like that.  When the author says that they are an heirloom, he is implying that Mike's set of brass knuckles has been handed down to him from his ancestors.  This implies that Mike's ancestors were criminals just like he is.