16 charts illustrating ocean temperatures a
© Science Museum / Science & Society Picture Library
16 charts illustrating ocean temperatures at different depths, taken from Reports of the Challenger cruise, 1872-76. HMS Challenger made a three year circumnavigation from December 1872 to May 1876. The voyage is particularly famous because it is said to mark the beginning of modern oceanography. The ship was adapted to accommodate the scientists' measurement of physical data and the collection of samples from the ocean and sea floor.