MAGNETIC OBSERVATIONS. 11 



The observations taken on shore, May 14th, were made on the northern side of 

 Flamenco Island, to the westward of a small cocoanut grove, and northeast of the 

 Naval Cemetery. The instruments were set up about ten feet north of the most 

 western of the ruins which are to be found there. The island is rocky, but at this 

 station the rocks are covered with earth. The spot was carefully tested for local 

 attraction by taking fore and back sights with a compass, but none could be detected. 



If we assume the position of the northeast bastion at Panama to be hit. 8° 56' 

 56" N., long. 5 h 18 m 4 S .6 W., as given by Capt. II. Kellet, R. N., then, according 

 to the English Admiralty Chart, the position occupied by the instruments is in 



Lat. 8° 54' 31" N. 

 Long. 5 h 18 m P.8 W. 



Acapulco,. Mexico. The ship was swung in this harbor, on June 1st, 1866, in 

 the usual manner. Her position at the time was lat. 16° 50' N., long. 99° 52' W. 

 Joint XII on the after turret was 5.5 inches to port. During the three days we 

 were lying at Acapulco the ship was swinging freely to the wind and tide. 



At the extreme south end of St. Lucia Bay, in this harbor, are two cocoanut 

 groves, the most western of the two containing the graves of a number of our naval 

 officers. The western end of the eastern grove is the place where the observations 

 taken on shore, on May 30th, were made. The trees come almost close down 

 to high-water mark, and the soil is a gray sand. The instruments were set up 

 about forty feet from high-water mark, at a spot from which the true bearing of the 

 gate of Fort St. Diego is N. 6° 22' E. 



If we assume the position of this gate to be lat. 16° 50' 56" N., long. 6 h 39 m 29 s .O 

 W., as given on the English Admiralty Chart, then, according to that chart, the 

 position occupied by the instruments is in 



Lat. 16° 50' 3" N. 

 Long. 6 h 39 m 29 s .4 W. 



Magdalena Bat, Lower California. An attempt was made to swing the ship 

 in this bay, on June 9th, 1S66, in the usual manner, but owing to a very stiff breeze 

 which was blowing at the time, she could only be turned through fourteen points. 

 Her position was lat. 24° 38' N., long. 112° 6' W. Joint XII on the after turret 

 was 5.5 inches to port. During the three days that we lay in this bay the wind 

 was so strong that the ship did not swing to the tide, but rode with her head con- 

 stantly to the west. 



As it is difficult to describe the land-marks here, the most convenient way of 

 giving positions will be to refer them to the English Admiralty Chart, the position 

 formerly occupied by Capt. Sir Edw. Belcher's observatory being taken to be lat. 

 24° 38' 18" N., long. 7 h 28 m 25 9 .4 W., as given on the chart. 



On June 8th a landing was effected at a spot on the beach, about a mile south 

 of the position of Capt. Belcher's observatory, for the purpose of making a set of 

 magnetic observations; but, after getting a time sight, it was found that there was 

 a great deal of local attraction, nearly all the stones on the beach being magnetic, 

 and consequently it was useless to attempt anything there. The approximate 

 position of this spot is 



