[Reprinted from Ocean Magnetic Observations, 1905-1916, and Reports on Special Researches. By L. A. Bauer, with W. J. Peters, J. A. Fleming, J. P. Ault, and W. F. G. Swann. Carnegie Institution of Washington Publication 175, vol. 3 (1917). Pages 6-7]
The brigantine Galilee, chartered for the period July 1905 to May 1908, was a wooden sailing vessel built in 1891 at Benicia, California, by her chief owner, Captain Matthew Turner, an experienced ship-builder. She was originally engaged in the passenger business between San Francisco and Tahiti, until crowded out by a line of steamers, since when she had been engaged in freighting between California ports and South Pacific islands. She was known as one of the fastest sailing-vessels of her size in the Pacific Ocean, her best record being 308 miles in a day with full cargo.*
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| Plate 2 |
Her length over all is 132.4 feet, beam, 33.4 feet, and depth 12.6 feet; her net tonnage is about 328 and displacement about 600. To fit her for the purposes of the magnetic expedition, the principal changes required were the substitution of hemp rigging** for the steel rigging, and the removal, as far as practicable, of all iron parts in the vicinity of the places of observation. The cabin space had to be enlarged for the accommodation of the scientific personnel. Furthermore, a special observing bridge, seen between the masts in the view (Plate 1, Fig. 3), was built, running fore and aft, and about 12 feet above the deck. The instruments mounted on this bridge were then, on the average, about 15 to 16 feet above the main deck and 25 to 30 feet from the remaining masses of iron, consisting chiefly of the iron bolts in the sides of the vessel. After the first cruise the observing bridge was extended, the galley removed to forward of the foremast, and some additional minor changes were made. (See Plate 2, Fig. 1.) For further information regarding dimensions and alterations of vessel, see J. F. Pratt's report on pages 128-134.
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 observations 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. Unfortunately, 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 Magnetism 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 William 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 expeditions, 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.
* While the Carnegie was at San Francisco in October 1916, the Galilee was berthed alongside the same pier. She has been converted into a 3-masted schooner, and is engaged in the Alaskan trade.
** This was obtained by special contract from a Philadelphia firm.