The German ship "Meteor" was the first to use the echo sounder for scientific purposes in the 1920s on the German Meteor expedition. For the first time an ocean, the Atlantic, was systematically mapped. The "Meteor" crossed the South Atlantic from the ice line to 20° N on fourteen mapping ways. With 67,000 echo soundings, cartographers were able to produce a modern depth chart. Other geomagnetic and oceanographic mapping expeditions followed e.g. the American research ship "Carnegie" in the Pacific Ocean from 1928 to 1929, the detailed reconnaissance in Indonesia by the Dutch "Willebrord Snellius", the exploration of the waters around the Antarctic by the British and "Discovery II" and the expedition of the American schooner "Atlantis" that sailed from the West Atlantic to the Gulf of Mexico between 1932 and 1938. Also the Scandinavian countries continued their activities at the end of the 1920s. Danish scientists devoted themselves to research in marine biology. The oceanographic "Dana Expedition", led by Johannes Schmidt and financed by the Carlsberg Foundation, was the most important Danish marine expedition. The treasured fish and plankton species belonged to the greatest collection of that time. The deceased John Murray had made a will stating that his invested inheritance would be used for an expedition as soon as enough capital would be accumulated. In 1931 was this the case and John Challenger Murray set work on realizing his father's wish. Since the envisaged research ships "William Scoresby", "Dana" and "George Bligh" were inapplicable or unavailable respectively, the offer of the Egyptian government to take the "Mabahiss" was accepted. The "Mabahiss" left Alexandria on September 3, 1933 and returned on Mai 25, 1934. During this period she covered the Red Sea, Bay of Biscay, Indian Ocean, and the Gulf of Oman—more than 22,000 nautical miles (41,000 km) whereas chemical, physical and biological assays were taken. The scientific leadership ran Seymour Sewell. In total, three British and two Egyptian scientists participated in this journey.