384 The Auroral Arch of March 20, 1865, as seen in Ireland. 



era edge was close to Aldebaran at the beginning of the 

 phenomenon; and that the left or southern edge was close to 

 Bellatrix at its ending. And if I remember rightly, it passed 

 over Pollux towards the end of the time, leaving Castor un- 

 covered; but as I have already said, the extremity close to 

 Arcturus showed no change of position. The gleaming of the 

 stars through the arch was very beautiful. They showed 

 through its delicate veil of light with undiminished bright- 

 ness, just as they did through the tail of Donates comet. Its 

 light was exceedingly white, and was for awhile considerably 

 brighter over Leo than elsewhere. 



After making these notes mentally, I walked some way 

 down an avenue which commands a view of the northern 

 horizon, but saw no auroral appearances there. The arch 

 became much narrower at the end of twenty minutes ; and at 

 the end of thirty minutes it was gone. About the manner of 

 its disappearance I cannot speak very confidently, as my 

 thoughts at the time were dwelling on the recollection of what 

 it had been at its brightest. 



I went out repeatedly during the evening to make sure of 

 the stars near which it should be marked on the globe, and I 

 saw no further appearance of aurora. 



The following account of the phenomenon of March 20th 

 appeared in the Irish Times, the writer (who signs. " J. B.") 

 stating that his place of observation was in lat. 53° 37' 45", 

 and long. 8° 46' 7" W., which denotes a position near Tuam : — 



"I beg to inform you of a remarkable display of the Aurora 

 Borealis which I witnessed on the night of Monday, the 20th 

 instant. Its principal feature was a very bright and well-defined 

 band that crossed south of the zenith from west to east, passing 

 under the planet Mars and over Orion, under Pollux, between 

 Leo and Coma Berenices, and under Arcturus. 



" The breadth of the band was about 8°, except toward 

 the east, where it narrowed, and ended in a point at the 

 confines of Bootes and Serpens ; and it was divided through 

 its whole length by a black fine, which reminded me of the 

 usual dark space in the tail of a comet. It swept across the 

 sky with a beautiful double curve that faced the north in the 

 meridian, and bent in the opposite direction as it approached 

 Bootes. It had a slight motion towards the south until its 

 edge touched Betelguese, at 7h. 50m., Dublin time, after 

 which it remained stationary until its disappearance. 



II The zodiacal light was very apparent in the west, and, 

 though its limits could not be well defined on account of the 

 aurora and the great brilliancy of Yenus, yet it could be traced 

 nearly to a point in the Milky Way, not far from where the 

 latter was traversed by the luminous band. The north- 



