The Carnegie's Cruises, 1909-16 173 



including a swing of the ship, the Carnegie reported her arrival at Honolulu on May 21. 

 An elaborate scheme of comparisons was carried out between the ship's magnetic instru- 

 ments and those of the Honolulu Magnetic Observatory, operated by the United States 

 Coast and Geodetic Survey, by which a correlation with other magnetic observatories and 

 standards was effected. Every faciUty for carrying out these comparisons at the observa- 

 tory was rendered by the observer-in-charge, W. W. Merrymon. On June 29 and July 3 

 the Carnegie was swoing off Pearl Harbor, in about the same locality as that of the Galilee's 

 swing of 1907. The results confirm the large differences which had been indicated by the 

 Galilee swing, between the values of the magnetic elements at the place of swing and at the 

 observatory, and they also give a means of supplying an additional determination of the 

 constant A of the deviation formula for the Galilee at Honolulu. The place of swing can 

 not be surrounded by land stations and hence can not be controlled by land observations. 

 This shows another advantage of a non-magnetic vessel over a vessel with deviations in a 

 magnetic survey of the oceans. After all the labor of planning, observing, and swinging 

 ship, and the tedious computations of the deviation parameters for a vessel having devia- 

 tions, one is confronted with the fact that hardly one of the few \-alues of A which can be 

 observed during a cruise is wholly above the suspicion of being affected by local disturbance. 

 One can only hope that the effect is neutralized in the mean of a number of observations at 

 the ports available. (For view showing observations at Honolulu Observatory, see PI. 17, 

 Fig. 4.) 



On July 20, 1915, the Carnegie reached Dutch Harbor, having sighted the Bogosloff 

 Islands. The commander's report on the sighting of these islands reads: 



"The Bogosloff Islands were seen at a distance of 3 miles at 2 a. m., July 20. There are two 

 islands at present, the eastern one terminating in two high twin peaks with sharp points at the top, 

 the western one having one high mountain with a broad top." 



When the Carnegie arrived at Dutch Harbor she had already covered 10,158 nautical 

 miles of her present cruise, in 73 days of saihng, at an average of 139 miles per day. During 

 this period 101 values of the magnetic declination and 56 each of inchnation and intensity 

 were observed at sea; besides an elaborate program of observations in atmospheric elec- 

 tricity was carried out. Observations for determination of the amount of atmospheric 

 refraction have been continued, as also the usual meteorological observations. 



The magnetic declinations observed on the Carnegie from Brooklyn to Dutch Harbor, 

 March-July 1915, showed that there had been a steady improvement in the nautical 

 charts since the data obtained during the previous cruises of the Galilee and Carnegie had 

 become available to hydrographic bureaus. The chart corrections reached a maximum 

 value of about 1 ?5 in the region of the Pacific, between Panama and Honolulu, not pre- 

 viously covered by these vessels. 



August 5, 1915, the Carnegie started on her long continuous passage to Lyttelton, New 

 Zealand. Heavy weather was encountered immediately, and it was impossible to swing 

 ship until August 15, just before leaving the Bering Sea. The farthest north was 59° 33'. 

 The 180th meridian was crossed on August 13, the date August 14, 1915, being omitted. 

 After clearing the Aleutian Islands, the course followed was south practically along the 

 165th meridian to New Zealand. On September 6 a terrific hurricane from the southwest 

 was encountered. It was necessary to take in all sail and run before the storm, and for 

 17 hours a speed of 9 knots was made under bare poles. The vessel stood the strain well, 

 but everything was wet on board, the hurricane driving the rain into every crack and 

 opening. Wake Island was passed in the morning of September 12. After passing the 

 first of the Marshall Islands, it was deemed best to keep pretty well to the east on account 

 of prevailing easterly winds and westerly set of the currents. It was necessary to pass 

 well to the westward of the Santa Cruz-Solomon Islands passage while near the equator, 

 but favorable conditions made it possible to weather the Solomon Islands, the engine 

 operating during cahns. 



