Magnetic Work of the Galilee, 1905-08 7 



While it was not possible to convert the Galilee completely into a non-magnetic 

 vessel, as would have been desirable, the changes resulted in reducing the deviation 

 corrections, due to the disturbing influence of the remaining iron, to such an extent 

 that the ship's so-called "magnetic constants" turned out to be smaller for this 

 vessel, on the average, than those of any vessel on which ocean magnetic observa- 

 tions had previously been made (see Table 36, p. 91). 



However, the corrections were still so large that it was necessary to take them 

 into account if the scientific requirements of the problem undertaken were to be 

 successfully met. These corrections had to be determined by special observations, 

 made while "swinging" ship in port and at sea as often as circumstances permitted. 

 This necessarily caused more or less delay in both the field and office work. Unfor- 

 tunately, experience had also repeatedly shown that these corrections, as based on 

 a mathematical analysis of the deviations, were troublesome to control adequately. 

 As the corrections arise chiefly from magnetic induction in the soft-iron parts of the 

 vessel, they are subject to various accidental conditions, such as the length of time 

 the vessel follows any one course, or the amount of buffeting the vessel has been 

 exposed to from the waves, etc. 



The preceding paragraph shows why it was found more economical in every way 

 to construct an entirely non-magnetic vessel specially built for the purpose when 

 the requisite funds became available. It seemed unfortunate to introduce, in the 

 very regions where the disturbances due to local magnetic masses are a minimum, 

 an extraneous source of disturbance by not having an entirely non-magnetic vessel. 

 However, conditions in 1905 did not permit our waiting for such a vessel. The 

 attempt was accordingly made to secure magnetic data as accurately as was 

 then possible and to solve the problem given to the Committee on Terrestrial Mag- 

 netism of the International Association of Academies in 1904 upon the proposal of 

 the late Professor von Bezold, viz, "the determination of the best methods of 

 making accurate magnetic observations at sea." 



Further interesting information regarding the Galilee and organization of the 

 work will be obtained from the charter-party (see page 8), which was drawn up 

 with the counsel of Judge WilUam W. Morrow of San Francisco, a trustee of the 

 Carnegie Institution of Washington. It should be recorded here that the firm of 

 Matthew Turner Company carried out the terms of the contract in a most faithful 

 and agreeable manner, ever evincing interest in the successful issue of the expedi- 

 tions, and always being alert and ready to keep the vessel in good repair. This was 

 the first of many pleasant experiences had throughout the ocean work thus far with 

 mercantile firms with whom it has been necessary, for one purpose or another, 

 to have business relations. Hearty cooperation and general interest have been 

 well-nigh universal. 



