Specimen Observations on the Galilee 



39 



Analysis of Horizontal-Intensity Deviations 



(Form 23a) 



Station: San Francisco Bay 

 Date: May 25, 1908, A. M. 

 Instrument: Sea Defl'r 2 (D2) 

 Magnets: 45 and 2L 

 Sea: S Weather: b 



Lat: 37° 51' N 



FcsseZ; Galilee 



Obs'r: D. C. S. 



WiTid: Temp; 14° C. 



Roll: 0° 



Lortff.- 122° 23' W 

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

 Comp'r: D. C. S 

 Reviser: J. P. A. 

 i/e/m; Both 



'Without Ah and expressed in units of the fourth decimal c. o. s. 



Total-Intensity Observations, San Francisco Bay, May 25, 1908. 



Form 12a, page 40, gives specimen total-intensity observations with sea dip-circle 189 

 by the deflection method, made on headings N and NE durmg the port-helm swing in San 

 Francisco Bay, May 25, 1908. The intensity needles used were Nos. 3 and 4. The form 

 is doubtless self-explanatory, the method of observation being, in general, the same as for 

 land work. (See Volume I, pp. 17, 18, 24, 29, 30, 39.) Here, however, the readings on 

 the ends of the suspended needle are recorded not to minutes of arc, but to the nearest half 

 or quarter degree. It will be observed that 4 readings are made on each end of the 

 suspended needle, for each position of circle and needle. All operations are carried out on 



