EXPEDITION TO POINT HARROW, ALASKA. 



407 



DIFFERENTIAL MAGNETIC OBSERVATIONS AT UGLAAMIi;. 



HOURLY READINGS OF TIIE BROOKE DECLINOMETER FliOM SEPTEMBER 12, 1882, TO A VO VST 27, 1883. 



(Increasing scale numbers denote increasing easterly declination. Value of one division of sciile between September 12, 1RS2. and November 

 3. la*t obwrval ion, a 1'.016; from November 4 to close of series, a 1.020 The averse scale rcmlintz, 484.7, cemspeoda :inpioxi- 

 matclv to !!5 37'. 2 E. declination. The presence of an nuroia in imliciitnl by letters, tluiH : (a) a trace just visible, (6) a feeble display, 

 (e) a moderate display, (rf) a bright appearance, (e) a bi illiant display. The I wo iT;;<liugs of tbe declinometer are given for each lumr, 

 as well as their m> nn' Tim two readings aro placed opposite the brace in the first column, and thpir mean directly below. The extrerna 

 scale divisions aro 200 and 800.] 



Hourly readings of the Brooke declinometer, Uglaamic, Alaska, September, 1882. 



[Gottingentime.] 



linn tu ivj]iu:e to :> uniform sy-,tcni. 

 ii',- to n nnit'o! in s.vstnn, 



.('onvrli'Mi to reduce to a uniform avstc.in, 21.2 

 Monthly mean, 521.7; correction, 24.2; corrected mean, 497. 'i 



Correctiou to reduce to a uni; 

 IfCorrectiou to reduce to a nnitonn RJ si. -ID 



