Columbia subject headings:
Equator--Description and travel.
Twain, Mark, 1835-1910--Travel.
Voyages around the world.
Harvard subject headings:
Australia
India
Twain, Mark, 1835-1910--Travel.
Voyages around the world
Princeton subject headings:
Twain, Mark, 1835-1910--Travel.
Voyages around the world.