GEODETICAL TABLES. 



Value of gravity on the earth at sea level Tabdc 90 



Relative acceleration of gravity at different latitudes . . . Table 91 



Length of one degree of the meridian at different latitudes . Table 92 



Length of one degree of the parallel at different latitudes . . Table 93 



Duration of sunshine at different latitudes . Table 94 



Declination of the sun for the year 1899 ... « . . » . Table 95 



Duration of astronomical twilight » . , Table 9O 



Duration of civil twilight Table 97 



Relative intensity of solar radiation at different latitudes. 



Mean intensity for 24 hours of solar radiation on a hori- 

 zontal surface at the top of the atmosphere .... Table 98 



Relative amounts of solar radiation received during the 



year on a horizontal surface at different latitudes . . Table 99 



Air mass, m, corresponding to different zenith distances of the 



sun Table 100 



Relative illumination intensities Table ioi 



