From late 1872 to 1876, H.M.S. Challenger explored the world's oceans, conducting deep sea soundings, dredging the ocean floor, recording temperatures, observing weather, and collecting biological samples. Following the ship's naturalists and their discoveries, Doug Macdougall engagingly tells a story of Victorian-era adventure and ties these early explorations to the growth of modern scientific fields. Along the way, Macdougall profiles naturalist Henry Moseley—who rigorously categorized the flora and fauna of the islands the ship visited—and John Murray, considered the father of modern oceanography.