Magnetic and Electrical Observations at Sea¹

Abstract

THE handsome volume before us is principally concerned with the magnetic and electrical observations made at sea by the Galilee (1905-8) and the Carnegie (1909-16). It also includes some observations made on shore in connection with the cruises of the two vessels. Some of the contents I appeal only to a narrow circle, but much is of general interest. Thus we have the “charter party” by which Mr. Matthew Turner, managing. owner of the brigantine Galilee, of the net tonnage of 328, contracted to maintain the vessel tight, staunch, sound, strong, and seaworthy with a sailing master, two mates, six seamen, and two cooks. Then we have the instructions issued by the director of the Department of Terrestrial Magnetism to the master before each cruise, the report of the master, the daily log, and particulars of all the instruments on board. The parts of; most general interest are the descriptions of the i observational instruments copiously illustrated in i the plates, the reduction formulas, the tables of| observational results, including the graphical illustration on pp. 424-29 of the errors in current magnetic charts, and the discussion of the electrical observations. A certain amount of the material has already appeared in a less complete form in earlier publications, but the present volume collects everything together and shows the gradual development of ideas.