324 CALIFORNIA ACADEMY OF SCIENCES. 



Mount Helena the value }.^=122- 38' 01/' 41. [This gives 

 for the present astronomical and telegraphic longitude sta- 

 tion, Lafayette Park in San Francisco, the longitude west 

 of Greenwich=:8A 09m 42.72s, or 122° 25' 40." 75.] 



These standard geodetic data (p^ «o ''•o ^^'® subject to 

 changes hereafter; but generally they are best retained 

 and the small corrections are noted, so long as the changes 

 do not exceed tlie respective probable errors of these quan- 

 tities. 



