Two or three of the boys had long been persons of consideration among us because they had been to St. Louis once and had a vague general knowledge of its wonders, but the day of their glory was over n

Two or three of the boys had long been persons of consideration among us because they had been to St. Louis once and had a vague general knowledge of its wonders, but the day of their glory was over now. They lapsed into a humble silence, and learned to disappear when the ruthless "cub"-engineer approached. This fellow had money, too, and hair-oil. Also an ignorant silver watch and a showy brass watch-chain. He wore a leather belt and used no suspenders. If ever a youth was cordially admired and hated by his comrades, this one was.

How does Twain's use of sarcasm in this excerpt help serve his purpose? Be sure to use specific details from the text to support your answer