though the only spout in sight was that of a Fin-Back, belonging to the species...

though the only spout in sight was that of a Fin-Back, belonging to the species of uncapturable whales, because of its incredible power of swimming. Nevertheless, the Fin-Back's spout is so similar to the Sperm Whale's, that by unskilful fishermen it is often mistaken for it. And consequently Derick and all his host were now in valiant chase of this unnearable brute. The Virgin crowding all sail, made after her four young keels, and thus they all disappeared far to leeward, still in bold, hopeful chase.
Oh! many are the Fin-Backs, and many are the Dericks, my friend.