. . . "And if anybody was to come to you and say, “I know the Javva currents,” don’t you listen to him; for those currents is never yet known to mortal man. Sometimes they’re here, sometimes they’re there, but they never runs less than five knots an hour through and among those islands of the Eastern Archipelagus. There’s reverse currents in the Gulf of Boni—and that’s up north in Celebes—that no man can explain.... "