Just a bit of a puzzle. Chapter 14 of Following the Equator has Sam and
party railroading from Sydney to Melbourne. The border of New South
Wales and Victoria has an abrupt change in railway gauge requiring the
passengers to disembark from one train and board the next. This was
done in the early morning chill. Twain's narrative has it with a narrow
gauge to the frontier and a wide gauge to Melbourne. The illustration
and chapter abstract has it the other way around.