36 



Ocean Magnetic Observations, 1905-16 



Analysis oj Declination Deviations 



(Form 23) 



Slation: San Francisco Bay 

 Date: May 25, 1908, A. M. 

 Compass: Ritchie 29499 (R3C) 

 Method: Prism and Alidade 

 Sea: S Weather: b 



Lat: 37° 51' N 

 Vessel: Gahlee 

 Obs'r: W. J. P. 

 Wind: 

 Roll: 0° 



Long: 122° 23' W 

 Com'd'r: W. J. P. 

 Comp'r: J. P. A. 

 Reviser: H. W. F. 

 Helm: Both 



'Without Aj. 



HoRIZONTAb-lNTENSITY OBSERVATIONS, SaN FrANCISCO BaY, MaY 25, 1908. 



Form 24, page 37, gives a specimen set of horizontal-intensity observations made 

 with sea deflector 2 (D2), during the swing in San Francisco Bay, May 25, 1908. On the 

 port-hehn swing, deflecting magnet 45, short deflecting-distance, was used, whereas on the 

 starboard-hehn swing, deflecting magnet 2L, short deflecting-distance, was used. To show 

 the method, it will suflace to give the observations made on the first half of the port-helm 

 swing, headings W, NW, N, NE. The headings of the columns and the adjacent desig- 

 nations will, m general, give the requisite explanations. 



The first column contains the magnetic course or ship's heading, as shown by the stand- 

 ard compass. In the second and third columns are entered, respectively, the time and 



