The cruise of the Albatross, or, When was Wednesday the tenth?

"ON the eighteenth day out from Sydney, we were cruising under the lee of Erromanga,-of course you know Erromanga, an isolated island between the New Hebrides and the Loyalty group,-when, suddenly, our dusky Polynesian boy, Nassaline, who was at the masthead on the lookout, gave a surprised cry to "Boat ahoy!" and pointed with his skinny black finger to a dark dot, away southward on the horizon, in the direction of Fiji."