EXPEDITION TO POINT BAHliOW, ALASKA. 



479 



Recapitulation of monthly mean valves (inclusive of disturbances) of hourly readings of the Jlrookc 



declinometer at Uglaamie, Alaska, 1882-'8.;. 



SOLAR DIURNAL VARIATION OF THE DECLINATION, INCLUSIVE OF DISTURBANCES. 



The daily variation of the magnetic declination is found by subtracting' each hourly mean from 

 the respective daily mean, and is given in the following table for the whole year, as well as for the 

 half years, i. e., with sun in north declination and sun in south declination : 



Apparent diurnal range, 6 months, sun north of equator, 41'..'} 

 Apparent, diurnal range, months, .sun south of equator, .'59'. 9 

 Apparent diurnal range, year, 40'. 1 



