DEPARTMENT OF TERRESTRIAL MAGNETISM. 257 



On March 1, 1917, the Recalada Ughtship, at the mouth of the Plata 

 River, was passed. After taking on the pilot the engine was started 

 and the Caimegie went up the river under her own power, reaching 

 Buenos Aires next morning, March 2, 1917. 



As usual, observations for magnetic intensity and inchnation at sea 

 were made daily, regardless of conditions of sea or weather. Magnetic- 

 dechnation results were obtained every day but four, which were too 

 cloudy for these observations. 



Tracks of the Galilee were crossed eleven times and the Carnegie's 

 tracks of former cruises were crossed seven times, thus affording several 

 opportunities for the determination of the annual changes in the mag- 

 netic elements for the regions covered. The total distance sailed was 

 14,775 miles, and the daily average for the 112 days at sea was 132 

 miles. 



Shore observations and instrumental comparisons were made at the 

 Argentine Magnetic Observatory located at Pilar. Comparisons had 

 previously been made at Pilar in 1911 during the first visit of the 

 Carnegie, and again by Observer H. P. Johnston in 1913, so that the 

 correlation of the Argentine magnetic work with that of the Depart- 

 ment has now been controlled three times. 



On account of the war it was considered best to detain the Carnegie at 

 Buenos Aires. The ocean work of Cruise IV was brought to a conclusion 

 and members of the party were assigned to other duties. Observer Jones 

 was instructed to proceed to Lima, Peru, where he joined Mr. Flem- 

 ing's party and was assigned to land work (see page 268) . Observers 

 A. D. Power and L. L. Tanguy were assigned to land work in Argentina, 

 viz, to reoccupy certain magnetic stations established by the Argentine 

 Government. Mr. George 0. Wiggin, director of the Argentine 

 Meteorological Service, assisted the Carnegie party in many ways and 

 greatly facilitated the work in Argentina. Through his efforts passes 

 over all the railway and steamship lines were given to each member of 

 the party, and free entry for all the scientific instruments was granted 

 by the customs department. At the sohcitation of the American 

 ambassador at Buenos Aires, the Argentine government extended port 

 facilities, wharfage, etc., freely to the Carnegie during her stay in port. 

 The Department takes this opportunity to express its thanks to the 

 government and people of Argentina for the many courtesies extended. 



On May 29, 1917, Capt. J. P. Ault, having been in conamand of the 

 Carnegie for three years, was instructed by cable to return to Washing- 

 ton via Valparaiso for conference and assignment to shore duty. After 

 completing all arrangements for turning over the command of the 

 Carnegie to Dr. H. M. W. Edmonds, who had been second in command 

 for three years, Captain Ault left Buenos Aires on June 10 for Wash- 

 ington, where he arrived on July 25. 



At the close of the fiscal year plans were being completed for the 

 Carnegie to return to the Pacific Ocean via Cape Horn or the Straits 



