answers: Captain George Nares
context: Shuttle "Challenger". 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 tasks, 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. </s> in mid-September. The expedition left Tahiti in early October, swinging to the west and south of the Tubuai Islands and then heading to the south-east before turning east towards the South American coast. The route touched at the Juan Fernández Islands in mid-November 1875, with "Challenger" reaching the port of Valparaiso in Chile a few days later. The next stage of the journey commenced the following month, with the route taking the ship south-westward back out into the Pacific, past the Juan Fernández Islands, before turning to the south-east and back towards South America, reaching Port Otway in the Gulf </s> of Penas on 31 December 1875. Most of January 1876 was spent navigating around the southern tip of South America, surveying and touching at many of the bays and islands of the Patagonian archipelago, the Strait of Magellan, and Tierra del Fuego. Locations visited here include Hale Cove, Gray Harbour, Port Grappler, Tom Bay (all in the vicinity of Wellington Island), Puerta Bueno (near Hanover Island), Isthmus Bay (near the Queen Adelaide Archipelago), and Port Churruca (near Santa Ines Island). The final stops, before heading out into the Atlantic, were Port Famine, Sandy Point, and Elizabeth Island. "Challenger" reached the
question: who led the challenger expedition from 1872 to 1876