96 Editorial Correspondence. 
Arr. XVII.—Observations on Skylight ORE in Ne- 
braska; by Epwarp A. CHa 
Tne observations with the Savart piusid of which a 
partial report was published in the September number of this 
ournal, were continued through the summer and a portion of 
the autumn. 
On account of the interruption caused by rain, clouds, and 
the camp duties of the Geological Survey, I was ‘unable to ac- 
complish so much as I desired ; but the low, unbroken horizon of 
the prairies appeared peculiarly favorable for observations upon 
the neutral points, ee: the following brief summary, may, per- 
haps, be worthy of record. 
No. of days on which obs. were made, 44 
“ of observations, 62 
Observations of Arago’ s neutral point, 
‘ Babinet’s ‘ : 59 
f «¢ Brewster's “ ee 19 
Simultaneous Observations. 
Arago’ sand Babinet’s n. ps, 36 
Arago’s and Brewster’s ‘“ 1 
Babinet’s and Brewster’s “ 17 
Arago’s, Babinet’s and Brewster’s, 
When Babinet’s and Brewster’s neutral points were both 
visible, 
Snantie'a appeared most distinct, 6 
Babinet’s “ “e a¢ 5 
Both were equally distinct, 6 
Thirteen of the observations were made when Brewster’s 
neutral point was below the horizon 
1—E£ditorial phe cate at 
Explorations in Russian America ; by W. H. tL, (from a let- 
ter addressed to J. D. Dana, dated Selous eitahabn, St. Mi- 
reechrerpye tel dali 13, 1867). 
Pale account of last season’s work i in ee sous may not = 
ave cross 
and have carefully ¢ xamined the geological 
the coun 
The Youkon river, the great central artery of this — of 
the territory, enters Alaska about midway between the Polar 
