322 CARNEGIE INSTITUTION OF WASHINGTON. 



ber 6, when Cape Henry was sighted early in the morning. At 

 11a. m., November 6, the Carnegie put in at Old Point Comfort and 

 about an hour later proceeded up Chesapeake Bay to ''swing ship" 

 the following day at the same place as in 1909. ''Swing observations" 

 were made for the magnetic elements on November 7, and the re- 

 duction factor for potential gradient was determined off Solomons 

 Island the next day. The results of the "swing magnetic observa- 

 tions" verified the absence of any appreciable "deviation-corrections" 

 at the observing places aboard the Carnegie. On November 9 the 

 Carnegie left for Washington, came up the Potomac with engine run- 

 ning, and docked at Smith's wharf at 5^ 30'" p. m., November 10. 

 The total distance at sea was 1,975 miles, which was made in 17 days 

 at an average daily speed of 115 miles. 



The Director joined the vessel at Balboa on October 12 for in- 

 spection of the work, and accompanied her on the return cruise to 

 Washington. Mr. R. R. Mills returned to the United States from the 

 Canal Zone to resume his university studies. Dr. F. A. Franke was 

 assigned to the ship's personnel at Balboa to take the place made 

 vacant because of the illness of Dr. Pemberton. 



The engine has been run very satisfactorily on many occasions 

 throughout Cruise VI. 



The total number of declination stations obtained during the cruise 

 from Port Lyttelton to Washington was 407, and the total number of 

 horizontal-intensity and inclination stations was 222 for each ele- 

 ment. The total distance covered was 29,384 nautical miles in 240 days 

 at sea, making an average daily travel of 122 nautical miles. The ave- 

 rage distribution of stations along the track of the cruise is very satisfac- 

 tory, namely, one declination station for every 72 nautical miles and one 

 horizontal-intensity and inclination station for every 133 nautical 

 miles. In addition to the magnetic work, atmospheric-electric obser- 

 vations have been carried out regularly for 4 or 5 atmospheric-electric 

 elements on each of 148 days, while diurnal-variation observations in 

 atmospheric electricity were made on 27 days. In addition, pitch- 

 and-roll records of ship's motion have been obtained frequently, 

 and daily meteorological observations and various observations for 

 determining geographic position have been made. Considerable time 

 has been devoted to obtaining further data regarding performance of 

 galvanometer and of earth-inductor on board ship, as shown by the 

 inductor observations, using the string galvanometer and the marine 

 d'Arsonval galvanometer on alternate days; the work with the string 

 galvanometer is not yet altogether satisfactory. Rock specimens were 

 collected at ports of call for Dr. H. S. Washington's investigations at 

 the Geophysical Laboratory. 



The ship's personnel has been as follows: J. P. Ault, chief of the 

 Section of Ocean Work, in command; H. F. Johnston, magnetician, 

 second in command; Russell Pemberton, surgeon; A. Thomson, H. R. 



