I like this illustration of a scene in Jules Vernes’s Twenty Thousand Leagues Under the Sea (1870) even more because it has at least one mistake in it. At least, I think it’s a mistake: the jellyfish on the upper left are two Portuguese men-o’-war (really colonial hydrozoans, not jellyfish). They have gas-filled float-bladders, so in reality you see them only on the surface, not hanging in midwater like that. The mistake makes the scene like a dream. The absence of colour is good too: it fixes the illustration firmly in the past and the colours you imagine are more vivid. The artist is imagining, dreaming, conjuring a vision of an oneiric ocean.