A boy from the town, trenching on Smith’s monopoly, was selling papers with the afternoon’s news.
GANGNES: MCCONNELL is somewhat at odds with HUGHES AND GEDULD and STOVER here; H&G's identification of "Smith" as referring to the newsagent W. H. Smith is important to the print culture of Victorian Britain. I include MCCONNELL to show that critical/annotated editions are not infallible.
From HUGHES AND GEDULD 205: "Cutting into or 'poaching on' W. H. Smith's monopoly of selling newspapers inside the station. The chain of W. H. Smith to this day has the exclusive rights to selling newspapers, magazines, and books in m any British railroad stations."
From MCCONNELL 153: "'Trenching' means encroaching. The newsboy is selling his papers at a station where Mr. Smith has a permanent newsstand."
From STOVER 91: "Reference to W.H. Smith, whose chain of stationery stores to this day has the exclusive rights to sell newspapers, books, and magazines in British railway stations."