CONTRIBUTIONS TO THE NATURAL HISTORY OF ALASKA. 35 



pale, prismatic colors, most often red. Vertical beams are sometimes noticed, but they rarely 

 intersect the halo of 22 degrees. They are more often 5 to 8 degrees above and below the sun or 

 moou. Like the parhelic circle, they contain no trace of coloration. The anthelion is seeu only 

 with the parhelic circle complete. 



In March, 1875, traces of parhelia, on the parhelic circle, indicated the presence of the halo of 

 90 degrees radius. In May, 1877, it was more plainly seen. 



MIRAGE. 



I have divided this phenomenon into two kinds, viz, vertical and horizontal, or lateral, the 

 vertical mirage being the commoner of the two. 



During the moderately fresh winds, or seasons of calm in winter on clear days, this kind of 

 mirage is seen. It lasts with varying intensity for the entire day, often extending along the coast 

 for miles. The horizontal mirage is less common and usually weak. Occasionally the high hill- 

 tops, off 30 or 40 miles, are thrown into the greatest confusion, or else extended laterally over a 

 considerable area, or distorted and broken. 



This kind of mirage seldom lasts more than half an hour after the sun has risen, and is the 

 most intense about half an hour before sunrise. 



The rapidity of motion is greater in the lateral than in the vertical kind. The low coast and 

 absence of trees and bare rocks on the hill sides do not allow of very much variety in either kind 

 of mirage. 



TWILIGHT CURVES. 



Twilight curves may be seen at any time after sunset or before sunrise, during clear weather. 

 Their occurrence being as certain as the setting of the sun, I have kept no record of them except 

 in the daily journal, and there have merely alluded to them as having occurred during the period 

 referred to. 



ELECTRICITY. 



Electricity has shown itself to be very abundant during the periods of great cold in winter. 

 Having no special instruments to determine intensity of kind, I shall confine my remarks to those 

 occasions when it was developed by friction of the hand on the fur of a dead animal. 



A couple of foetal seals had been stuffed with straw, and as my hand was stroking them one 

 evening in the dark I noticed sheets of electricity to follow the hand, accompanied by the charac- 

 teristic crackling. I then tried an india-rubber comb on my dry head, and found that very con- 

 siderable sparks could be drawn out. 



At another time I had occasion to tear a piece of muslin that had been washed, and being 

 where the temperature was at least minus 16° Fah., I found that by simply tearing the cloth a 

 streak of light much like that produced by drawing a match across the moist palm of the hand in 

 the dark could be plainly seen. I repeated the experiment several times, and extended it to stiff 

 manila paper, and with the same results. 



I requested Mr. Neumann, agent of the Alaska Commercial Company, to try the experiment, 

 and some time afterward he assured me of his success in producing t?he same results. 



In fact, the air seems to be filled with electricity during the above mentioned periods. This 

 naturally brings me to the magnetic variation of this place. 



I placed the compass carefully on a board constructed to point due north, and for months 

 at a time I have never seen a tenth of a degree variation of the needle from 23 degrees east, not 

 even a tremor being observed during an auroral display. This 22 degree (?) variation is exactly 

 what Capt. E. E. Smith, of the schooner Eustace, informed me had been before determined, but 

 by whom ascertained is unknown to me. 



AURORAS. 



The auroral displays seen at this station naturally divide themselves into two classes, accord- 

 ing to their intensity. 



The first of these is what I have described as an auroral haze. It has very slight intensity, 

 no particular form, seldom lasts long, and more seldom recurs. This is the most common display 

 recorded. 



