276 A. C. Twining—Aurora of Feb, 4th, 1872. 
10" 20". Crimson in S.E., S&S, and S.W.—especially in 
Canis Maj. and lower half of Orion,—extending 10° to 20° E. 
of Sirius, which was still in brightest part. Upper margin per- 
° . eg 
f 
Respecting this same aurora, Prof. C. G. Rockwood of 
Bowdoin College, obligingly communicates, among other things, 
the following :— 
“On the evening of Feb. 4th, at Hudson, I saw it first a 
little before 7 Pp. M., being a brilliant patch of red light in the 
S.E. It was of irregular shape, the brighest part being about 
over the three stars Alpha, Beta and Gamma Leporis—say in 
A.R. 82° Dec. —20°, and extending with a variable breadth, like 
a bank of colors, toward and over the triangle formed by Delta, 
Epsilon and Eta Canis Maj.—say across a point in A. R. 100, 
Dec. —28°. At 7 P. M. there were visible two or three faint 
white streamers stretching far *p toward the zenith and resting 
upon the red as a base. The 12d mass continued visible, though 
varying in intervals, until atter 11 o’clock. At 11> 30" P. ™ 
it had faded away. 
I had given up all hope of any parallax, from the remarkable 
fact that the red patch retained the same position among the stars 
all the evening, moving with them from west to east. Prof. 
Brackett, who observed the phenomenon here [Bowdoin Coll. 
lat. 48° 54’ long. 69° 57’], noticed the same thing.’ 
In addition to the foregoing, Assistant Arthur Searle of Harv- 
ard Coll. Observatory, has obligingly communicated the fol- 
owing: 
z The red southern arch of Feb. 4 was very ill defined. 
I have the following notes: ‘At 6° 25™ p. mu. reddish light 
diffused from below Orion to square of Pegasus’ [90° extent]; 
at 7 35™ band in the south nearly white, covering most, o 
Canis Major. Mr. Trouvelot, observing here, made the following 
otes: ‘At 8" 15™ p. M., arch dark purple, about 8° or 10 wide 
where it was broadest; its northern edge nearly reaching the 
nebula of Orion, very vaporous and ill defined.’ At 8" 40" 
just reached the Orion nebula. At 10" 50™ lower than before, 
and almost exactly resembling in form the pale arch ™ the 
age as a . vee a reflection of it.” : ; a 
e problem relative to actual height in the early eve 
ea 9 : easured 
in a direction across itself, appears to have been 8° between 
° 'W. from it,—and 54° between New Haven and the samé 
being 158? miles, S. i i 
73° of parallax in the azimuthal p Oe aa 
oo — seem to be indicated = the foregoing, 0¥ 
specific results cannot be attempted at this point. 
_ This anrora’ was observed with the spectroscope by Professot 
