The Blue Lagoon by H. De Vere Stacpoole

"Mr. Button," said she, when the latter had descended, "there's a little barrel"; she pointed to something green and lichen-covered that lay between the trunks of two trees -- something that eyes less sharp than the eyes of a child might have mistaken for a boulder.

"Sure, an' faith it's an' ould empty bar'l," said Mr. Button, wiping the sweat from his brow and staring at the thing. "Some ship must have been wathering here an' forgot it. It'll do for a sate whilst we have dinner."