Through a naturalist’s eyes
"In 1872, HMS Challenger, stripped of her guns and with a party of scientists on board, set out on a voyage around the world that lasted over three years. The cruise was a landmark in the history of oceanography and transformed ideas of the ocean environment. For instance, life was found in the horribly inhospitable cold, dark depths of the abysses, miles below the surface. Until then, there was believed to be an Azoic or Lifeless Zone below 300 fathoms, even though Sir James Clark Ross had already collected starfish and other animals down to 1,000 fathoms."