As early as 1834 Edward Forbes had made biological investigations in the Irish Sea, and in 1841–42 in the Mediterranean; while in 1868–70 similar studies, together with soundings and observations for water-temperature, salinity, and deposits, were carried on in the British seas, the Bay of Biscay, and the Mediterranean by investigators on board vessels of the Royal Navy--the _Lightning_, _Porcupine_, and _Shearwater_. This and similar work elsewhere was preparatory to the greatest of all marine scientific expeditions, that of H.M.S. _Challenger_ in 1872–76. That vessel was commissioned at the instigation of the Royal Society, in command of Captain (afterwards Sir) George Nares, and a scientific staff under Sir C. Wyville Thompson as director, and including Sir John Murray, H. N. Moseley, and J. Y. Buchanan. The Atlantic was the first field of study, and was crossed several times; the southern ocean was then traversed south-east and east from Cape Town; the _Challenger_ was the first steamer to cross the Antarctic circle, and afterwards proceeded into the Pacific. The route now lay from Melbourne to New Zealand, Fiji, Torres Strait, the Malay Archipelago, and Chinese and Japanese waters, after which the Pacific was crossed from Yokohama by Honolulu and Tahiti to Valparaiso. The homeward route lay by the Straits of Magellan, Montevideo, Ascension Island, and the Azores. Every branch of oceanographical research was fully dealt with in the fifty volumes of reports upon the voyage. More lately other vessels of the British, American, German, and other navies have been detailed for scientific research; and cable laying has afforded additional opportunities. Mention must be made of the Dutch expedition in the eastern Malay seas on board the _Siboga_ in 1899–1900, the work of the German surveying vessel _Planet_ in the Pacific and elsewhere in 1906 and following years, and the Atlantic expedition of Sir John Murray and Dr. Johan Hiort on the _Michael Sars_ in 1910. The observations of the last-named expedition, especially on the distribution of life in the sea, are of the first importance. Oceanographical work has remained an integral function of scientific expeditions in the Arctic and Antarctic regions. Among the names of investigators which are specially identified with oceanography (independently of other departments of geographical research) reference is perhaps most justly due to those of Professor Alexander Agassiz in the United States, and the Prince of Monaco. The establishment of the International Council for the Study of the Sea in 1901, nominated by nine European Governments, with its headquarters in Copenhagen, was not only an outstanding event in the history of the science at large, but also draws attention to one of its most important practical applications, for the Council is specially concerned with the study and improvement of the fisheries in the North Sea and other European waters.