Captain Parry's Third Voyage. 167 



ly the same position. The Aurora usually consisted of an arch sometimes 

 tolerably continuous, but more frequently broken into detached irregular 

 masses, or nebula? of light stretching generally from about W. to S. E. 

 but sometimes a few points beyond these bearings. Its termination to the 

 S. E. was never exactly visible from the height of the land, but the arch 

 was more frequently bisected by the plane of the magnetic than by that of 

 the true meridian. The height of the upper margin of a permanent arch sel- 

 dom exceeded 10° or 15° and coruscations generally shot from this towards 

 the zenith. Sometimes the arch itself passed as high as the zenith, and on 

 one occasion, 28th January, its direction was N. and S. The lower edge of 

 the arch was generally well defined and unbroken, and the sky beneath it 

 appeared by contrast so exactly like a dark cloud, that nothing but the stars 

 shining in it removed the deception. 



There were few brilliant displays of the Aurora during the winter. A 

 fine Aurora appeared on the 21st December 1824, but a very remarkable 

 and instructive one showed itself on the 27th January 1825. It broke out at 

 midnight in a single compact mass of brilliant yellow light, situated in about 

 a south east bearing, and appearing only a short distance above the land. 

 Though generally continuous, it sometimes seemed composed of numerous 

 pencils of rays compressed as it were laterally into one, being well defined 

 on both sides, and nearly vertical. Though at times bright, its intensity 

 unceasingly varied, and it seemed produced by one volume of light over- 

 laying another as in clouds of smoke. While Captain Parry and Lieute- 

 nants Sherer and Ross were admiring the phenomenon, they simultaneously 

 uttered an exclamation of surprise at seeing- a bright ray of the Aurora shoot 

 suddenly downward from the general mass of light, and between them 

 and the land, which ivas then distant only three thousand yards. This 

 we conceive to be one of the most important facts respecting the Aurora 

 Borealis which has ever been published, and extinguishes at once many of 

 the absurd explanations of it, which have been given to the world. 



Captain Parry frequently listened for any sound proceeding from this 

 phenomenon, but never heard any. He likewise endeavoured in vain to 

 observe any influence upon the electrometer. 



One of the most important observations of Captain Parry, however, re- 

 lates to the circumstance which he seems to have completely established, 

 that the Aurora Borealis exercises no action whatever on the magnetic needle. 

 " Our variation needles," says Captain Parry, " which were extremely light, 

 suspended in the most delicate manner, and from the weak directive ener- 

 gy, susceptible of being acted upon by a very slight disturbing force, were 

 never in a single instance visibly affected by the Aurora, which could scarce- 

 ly fail to have been observed at sometime or other, had any such distur- 

 bance taken place, the needles being visited every hour for several months, 

 and oftener when anything occurred to make it desirable." 



The scientific reader will feel considerable surprise when he compares 

 the preceding distinct statement, with the statements published in the 

 Annates de Chimie by M. Arago, who not only finds that his magnetic 

 needle in Paris is affected by the Aurora? which are seen to the north of 



