Challenger expedition

The Challenger expedition of 1872–76 was a scientific exercise that made many discoveries to lay the foundation of oceanography. The expedition was named after the mother vessel, HMS Challenger.

Prompted by Charles Wyville Thomson—of the University of Edinburgh and Merchiston Castle School—the Royal Society of London obtained the use of Challenger from the Royal Navy and in 1872 modified the ship for scientific work, equipping her with separate laboratories for natural history and chemistry. The expedition, led by Captain George Nares, sailed from Portsmouth, England, on 21 December 1872. Other naval officers included Commander John Maclear. Under the scientific supervision of Thomson himself, she traveled nearly 70,000 nautical miles (130,000 km) surveying and exploring. The result was the Report Of The Scientific Results of the Exploring Voyage of H.M.S. Challenger during the years 1873-76 which, among many other discoveries, cataloged over 4,000 previously unknown species. John Murray, who supervised the publication, described the report as "the greatest advance in the knowledge of our planet since the celebrated discoveries of the fifteenth and sixteenth centuries". Challenger sailed close to Antarctica, but not within sight of it.

As recently as the late 19th century, human knowledge of the oceans was confined to the topmost few fathoms of the water and a small amount of the bottom, mainly in shallow areas. Sailors and scientists knew almost nothing of the ocean depths. The Royal Navy's efforts to chart all of the world's coastlines in the mid-19th century reinforced the vague idea that most of the ocean was very deep, although little more was known. As exploration ignited both popular and scientific interest in the polar regions and Africa, so too did the mysteries of the unexplored oceans.

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