32 



REPORT ON 



True bearing of sun . . . . . . . N. 71 49' W. 



Z Peak to sun 87 14 



True bearing of Peak S. 20 57 W. 



Observations to determine the true bearing of the object used as an azimuth mark in swinging the ship 

 in the harbor of Acapulco, Mexico. 



When determining the magnetic declination with the portable declinometer, on May 30th, 1866, 

 an observation of the sun with the theodolite gave N. 6° 22' E. as the true bearing of the gate of 

 Fort St. Diego from the shore station. We then have 



True bearing from station to Fort N. 6° 22' E.' 



Z Monadnock to Fort ....... 26 54 



True bearing from station to Monadnock . .. . N. 20 32 W. 



True bearing from Monadnock to station . . . S. 20° 32' E. 



Z Clump to station ........ 87 45 



True bearing of clump N. 71 43 E. 



Observations of the Sun, made June gth, 1866, to determine the true bearing of the object used as an 

 azimuth mark in swinging the ship in Magdalena Bay, Lower California. 



Owing to a combination of unfortunate circumstances, the only available method of determining 

 a true bearing was by observing with the solar compass, set up on the quarterdeck of the ship. In 

 that way I found 



True bearing of Peak ....... S. 46° 30' E. 



which can only be considered as a near approximation to the truth. 



Observations of the Sun, made June 23d, 1866, to determine the true bearing of the object used as an 

 azimuth mark in swinging the ship at San Francisco, California. 





7 h 5 m i7 8 



6 52 



7 55 



a 



s 



c 



r 

 a 

 b 

 C 



92° 22' 

 39 

 43 



T 

 Chronometer fast 



* 



7 6 41 



3 12 



— 1 5i 



92 35 

 + 17 



Apparent time 



7 1 38 



92 52 



t 

 S 

 4> 



M 

 $ — M 



— 74 35' 

 23 26 

 37 48 

 58 3° 



— 20 42 



64 8 

 — 2 

 64 6 

 89 5i 

 93 16 



True bearing of sun 

 Z Red Rock to sun . 



N. 79° 26' E. 



93 16 



True bearing of Red Rock N. 13 50 W. 



The following triangulation was made for the purpose of determining the geo- 

 graphical position of some points in and about Ceara, Brazil. The angles were 

 observed on December 14th, 15th, and 16th, 1865. Those between the Powhattan, 



