James Percy Ault, 1881-1929

The Department of Terrestrial Magnetism of the Carnegie Institution of Washington has suffered an irreparable loss in the untimely death of Captain J. P. Ault, chief of its Section of Ocean Work and Commander of the non-magnetic ship Carnegie. On November 29, 1929, while a supply of gasoline was being taken on board in the harbor of Apia, Western Samoa, an explosion took place as a result of which Captain Ault lost his life, and the vessel, together with all its instrumental equipment, was destroyed. Thus the extensive program of the seventh cruise of the Carnegie, which up to that time, under the able direction of Captain Ault, had yielded most valuable contributions to our knowledge of the oceans, was brought to an abrupt termination.Captain Ault was born on October 29, 1881, at Olathe, Kansas, and educated at Baker University where he received an A.B. degree in 1904. Even while studying in the University he took an active interest in the work of the then newly established magnetic observatory of the United States Coast and Geodetic Survey at Baldwin, Kansas, where he served as observatory assistant from January 1901 to June 1904. In the latter month he was appointed as magnetic observer in the Department of Terrestrial Magnetism and the next year, after receiving the necessary preliminary training on the U.S. Coast Survey vessel Bache on a cruise from Baltimore to Panama, he was assigned to scientific work on the magnetic-survey vessel Galilee where he remained until November 1906. During the next two years he was engaged at the office of the Department in Washington and on magnetic field work in Mexico and Canada, carrying out in the latter country a difficult exploratory trip in the course of which he secured magnetic results in territory where none had previously been obtained. In order to fit himself more thoroughly for a scientific career he next pursued postgraduate studies at Columbia University from which institution he received an A.M. degree in 1909. In view of his skill and experience gained on earlier expeditions, he was again, in 1912, placed in charge of field parties in Peru, Bolivia, and Chile, for the purpose of training new observers in making magnetic determinations under field conditions. In the course of the ever-broadening scope of the Department's activities, special investigations were early instituted for determining possible variations in the Earth's magnetic and electric fields due to a total solar eclipse, and in the case of the solar eclipse of September 10, 1923, at Point Loma, California, and that of January 24, 1925, at Greenport, Long Island, it was Captain Ault who was selected to assume the responsibility of directing these delicate measurements.