This portion of the series consists of observations made on board Her Majesty’s ships Erebus and Terror, from June 1841 to August 1842, in the Antarctic Expedition under the command of Captain Sir James Clark Ross, R. N., F. R. S. It comprises the result of the operations conducted during the second year of the expedition, when it proceeded early in July 1841, from Hobarton to Sydney, and thence to the Bay of Islands in New Zealand, remaining there till November, and reaching, in February 1842, in latitude 78°, the icy barrier which had stopped their progress in the preceding year. Quitting the antarctic circle in March, and keeping nearly in the 60th parallel, they crossed the whole breadth of the Southern Pacific Ocean to the Falkland Islands, where they arrived in April 1842. On a general review of the magnetic declination in the southern Hemisphere, the phenomena are found to present the same obvious and decided features of a duplicate system as those of the northern. Particular attention is given to those lines traversed by the ship’s course where the needle attains its maximum declination, whether easterly or westerly, as affording valuable data for the estimation of secular variations. The results obtained by the present expedition confirm the conclusion deducible from those of previous navigators; namely, that the spaces in the Southern Pacific, distinguished by certain magnetic characters, undergo a movement of translation, of which the general direction is from east to west; a direction which is the opposite to that in which a similar change takes place in the corresponding regions of the northern hemisphere; namely, in the Siberian quarter, where the secular movement is from west to east.
Diatom Phytoplankton Studies in the Southern Pacific Ocean, Composition and Correlation to the Antarctic Convergence and Its Paleoecological Significance