Feb. 14, 1859.] "AURORA BOREALIS" IN GREENLAND. 121 



at other times with upright pencilled rays, until they appear again to shoot 

 to and fro, and gradually disappear in the southern sky. Streamers, too, 

 frequently shoot, as he has described them, from perhaps an altitude of 50 to 

 60 degrees, more or less, and are visible in various places almost at the same 

 moment of time. They vanish at their northern faces, and reappear afresh at 

 their southern, being again projected downwards until they disappear in the 

 southern horizon ; lost to sight for a brief interval, and bursting instan- 

 taneously into view ; once more drooping and expiring when the southern 

 fringe had reached 30 degrees south of the zenith. I have seen at Fort 

 Keliance, two years in succession, many such appearances ; but on one parti- 

 cular occasion the sky was generally diffused with the aurora, which quickly 

 separated into arches, beams, and rays, and darted to and from the opposite 

 horizons ; then as suddenly opened up into bands or curves. It speedily rushed 

 across the zenith, nearly to the opjjosite horizon; became broken up in 

 different forms ; darted upwards anew and formed near the zenith a beautiful 

 corona borealis ; then, dispersing in an instant of time, it formed itself into 

 six distinct figures, representing the letter S, and moved with incredible velo- 

 city, thus presenting the strange appearance of so many huge snakes whirling 

 and twisting in every direction, until exhausted, as it were, by excess of 

 motion, the beautiful phenomenon again receded and dissolved in the south, 

 leaving in the spectator a sense of extreme loneliness, almost painful. As for 

 the colours of the aurora, they appear nearly, as Mr. Tayler has stated, from 

 steel grey to pale yellow, orange, red, «fec., varying in lustre according to circum- 

 stances. The aurora is seldom seen at a lower angle than 4 degrees from the 

 horizon. I may say, in the first instance, that there are two motions, the direct 

 and the lateral. The direct motion of the aurora is usually in a plane, seldom 

 varying more than 22 degrees from the magnetic meridian ; while the lateral 

 motion is at right angles to the magnetic meridian. Thus, an arch of the 

 aurora will sometimes move from the zenith 60 or 70 degrees towards the 

 southern horizon, whilst its extremities east and west remain nearly stationary. 

 Beams and flashes, contrary to the others, are generally inclined in the direction 

 of the dipping needle. Near the magnetic meridian they assume a position 

 perpendicular to the horizon ; but at some distance east and west they decline 

 towards the perpendicular, at different angles, having occasionally a small 

 deviation of parallelism among themselves. I think Mr. Tayler says that 

 the aurora, according to his observation, is not a luminous or electric vapour 

 reaching to the earth. It is true that in seven winters I never saw the 

 common cork-ball electrometer charged ; but with a more delicate instrument 

 — more susceptible — I have seen it drawn away 25 minutes, and afterwards 

 to upwards of 30 degrees. As regards magnetism, which is always interesting, 

 I may mention, that Professor Christie, who was then Secretary of the Eoyal 

 Society, had a needle 8| inches in length made expressly for me. It was sus- 

 pended so delicately that the slightest cause of disturbance affected it. This 

 needle was frequently disturbed by the aurora. On one occasion it was 

 deflected to 7° 50', consequently nearly to 8° on one side of its zero, at a 

 temperature of 20" minus zero. The arc of the instrument was only graduated 

 to 10°, thus putting at rest for ever the question of the aurora affecting the 

 needle. I may also mention in connexion with the same instrument, that 

 when the arches have been urged with a counter-motion from one horizon 

 to another, across the magnetic meridian, the needle has vibrated to and fro, 

 east and west of its zero, and then again suddenly stopped ; and at one time 

 actually dipped at one end of the needle 8 minutes. As to the height of the 

 aurora there are various opinions. One philosopher thought it to be 800 

 miles high. Another, Mr. Dalton, considered it to be 100 miles ; but that 

 was deemed to be erroneous. In our more recent journeys and voyages to 

 the northern regions, it was the general opinion, founded on observation, that 



