HMS Challenger, a wooden corvette of 2,306 tons, was commanded by Captain (later Sir) George Strong Nares, while Sir C. Wyville Thomson supervised the scientific staff. The expedition gathered observations from 362 stations and made 492 deep soundings and 133 dredgings. Among the results of the Challenger Expedition were determinations of oceanic temperature, ocean currents, and the depths and contours of the great ocean basins; charting, surveying, and biological investigations were also carried on. Later explorations supplemented the findings of the Challenger group but did not materially alter them; the scope and thoroughness of the expedition made it a landmark in the history of undersea exploration. The Report on the Scientific Results of the Voyage of H.M.S Challenger was issued in 50 volumes between 1880 and 1895; many of the data gathered at that time are still used today.