Half Mile Down - 1934 essay by William Beebe on his descent in a bathysphere. - http://seawifs.gsfc.nasa.gov/OCEAN_PLANET/HTML/ocean_planet_book_beebe1.html
William Beebe: Going Deeper - Biography of the naturalist and his deep-sea explorations. - http://www.pbs.org/wgbh/amex/ice/sfeature/beebe.html