STANDARD GEODETIC DATA. 321 



GEODEIIC OK STANDARD LATITUDE c OF MOUNT HELENA, 

 FOR THE "DAVIDSON QUADRILATERALS." 



Astrouomical 

 Station. 



Year 



of 



Obii. 



S. E. Yolo Base. 

 N.W.Yolo Base. 



Monticello 



Vaea Mt 



Mt. Diablo. . . 

 Mt. Tamalpais. 



Mt. Heleua 



Mt. Lola 



Round Top 



Observed 



Astrou'mic' 



Latitude. 



18^0 38 

 1880 38 

 1880 38 

 1880 3 S 

 1«76 37 

 1882 37 

 187638 

 1879 39 

 1879 38 



31 34.R2 

 4 1 37.34 

 Hd 46.51 

 22 23.3s 

 52 49.59 

 55 19.04 

 40 01.02 

 25 57.98 

 39 46 89 





to. 06 

 0.07 

 0.09 

 00; 

 0.06 

 0.08 

 0.06 

 0.(16 

 0.08 



Adopted 

 Geodetic 

 Latitude. 



(G). 



38 31 

 :J8 40 

 38 39 

 38 22 

 M 52 



37 55 



38 40 

 :59 25 

 3^ 39 



35.41 

 38.03 

 43.8.- 

 27.02 

 4S.70 

 20.69 

 04 26 

 53 34 

 43.64 



Mean . 



— 1.34 



—('.83 

 +2.20 

 —3.39 

 +0.70 



— 1.82 

 —2.99 

 +3.96 

 + 2.74 



—0.09 



The .mean difference, A — G, is small, approximating 

 zero, as it should be. AVe have, therefore, retained and 

 adopted for the present <p^ for Mount Helena 38" 40' 04.26'', 

 with a probable uncertainty of ± 0.' 59. The average local 

 deflection in the meridian is about 2. "2. 



GEODETIC OR STAND AED AZIMUTH a^ OF DIRECTION MT. HELEXA 

 TO MT. DIABLO, FOR THE "DAVIDSON QUADRILATEBALS." 



