J 68 Analysis of Scientific Books and Memoirs. 



Leitli in Scotland, but who even ventures to predict the occurrence of Au- 

 rora? at Leith, from the indications of his magnetic needles in Paris. As 

 the extraordinary Aurora of the 27th January 1825, whose distance from 

 Captain Parry's needle could not exceed one mile and a half, did not in 

 the least degree affect his delicately suspended needles, we must ascribe 

 the influence of the Leith Aurora? to some ethereal delicacy in the Pari- 

 sian needles, one of which we hope Captain Parry will take out with him 

 in his approaching journey to the Pole. If the English needles shall be 

 found as delicate as the French ones, which, with our nationality, we may 

 suppose to be the case, we must then conclude, that the Leith Aurora; pos- 

 sess physical properties totally different from those which enliven pur arc- 

 tic winters ! 



In Davis's Straits on the 15th September 1825, Captain Parry encoun- 

 tered, in latitude 69£°, a very brilliant Aurora in the S. E., and on the 20th 

 there was a bright arch across the zenith from S. E. to N.-E., which seem.' 

 ed to be very close to the ship, and which threw the shadow of objects on 

 the deck. 



The most brilliant display, however, of the Aurora, and which surpass- 

 ed all that be had seen at Port Bowen, occurred on the 24th September in 

 latitude 58*°, and longitude 44£°. " It first appeared," says he, " in a (true) 

 east direction, in detached masses like luminous clouds of yellow or sul- 

 phur-coloured light, about 3° above the horizon. When the appearance 

 had continued for about an hour, it began at 9 p. m. to spread upwards, 

 and gradually extended into a narrow band of light passing through the 

 zenith, and again downwards to the westward horizon. Soon after this 

 the stream seemed no longer to emanate from the eastward, but from a fix- 

 ed point one degree above the horizon on a true west bearing. From this 

 point, as from the narrow point of a pencil, streams of light resembling 

 brightly illuminated vapour or smoke appeared to be incessantly issuing, 

 increasing in breadth as they proceeded, and darting with inconceivable 

 velocity, such as the eye could scarcely keep pace with, upwards towards 

 the zenith, and in the same easterly direction which the former arch had 

 taken. The sky immediately under the spot from which the light issued, 

 appeared, by a deception very common in this phenomenon, to be covered 

 with a daik cloud, whose outline the imagination might at times convert 

 into that of the summit of a mountain, from which the light proceeded 

 like the flame of a volcano. The streams of light, as they were projected 

 upwards, did not consist of continuous vertical columns or streamers, but 

 almost entirely of separate, though constantly renewed masses, which 

 seemed to roll themselves laterally onward with a sort of undulatory mo- 

 tion, constituting what I have understood to be meant by that modification 

 of the Aurora called the " merry dancers," which is seen in beautiful per- 

 fection at the Shetland Islands. The general column of the light was 

 yellow, but an orange and a greenish tinge rose at times very distinctly 

 perceptible, the intensity of the light and colours being always the great- 

 est when occupying the smallest space. Thus the lateral margins of the 

 <band or arch seemed at times to roll themselves inwards so as to approach 



