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64 . Remarks on the Tails of Comets. 
ed so near the sun that it became very brilliant, and was more- 
over accompanied by three distinct envelopes, a condition favora- 
ble, it must be acknowledged, to the multiplication of tails, es- 
pecially when we notice that the ratio is such as to produce the 
number usually assigned, each beam of light being numbered as 
atail. 'The diversity of circumstances exhibited in the heads of 
different comets, renders it rather a matter of surprise that so great 
a uniformity should prevail in the general circumstances of the 
tails. ®. 
We come next to the consideration of another and a distinct 
class of phenomena, that of the secondary tail; or what Prof. Jos- 
lin denominates the “supernumerary tail,” distinguishable in the 
comets of 1823 and 1835. The former was noticed by Prof. Biela, 
at Prague, and President Day, of Yale College, and by them rep- 
resented as forming an angle of 178° with the primary tail. The 
latter was noticed by many observers in this country at various 
angles with the primary tail, a singular discrepancy prevailing in 
the various published accounts. Of this extraordinary appeat- 
ance in the comet of 1823, I have only to express my conviction, 
not having myself seen it, that it proceeded from the same cause 
that produced the same phenomenon in the comet of 1835, which 
was most manifestly the image of the true tail of the me 
jected on the spherical surface of the envelope, visible only under 
fixed angles, and changing its aspect and position with the rela- 
tive change in the position of the three bodies, aflected also by 
fluctuations in the comet’s envelope. So faithful was the delin- 
eation, that the brighter borders of the tail gave to the reflected 
image the form of a sector. 
Our writer having denounced all theories as equally unsatisfac- 
tory, recalls the expression, and acknowledges the theory of Dr. 
Hamilton, of Dublin, to “approach nearer the truth than any with 
which he is acquainted.” 
The theory of Hamilton supposed the tails of comets and the 
Aurora Borealis to be kindred effects of electricity. In support 
of this theory, the writer adduced a remark of Halley, “that the 
streams of light so much resemble the long tails of comets, that 
at first sight they might well be taken for such ;” and asa ful- 
ther confirmation of this theory, introduces the following quota 
tion from Prof. Vince’s System of Astronomy, viz. “'The comet 
of 1607 appeared to shoot out at the end of its tail. Le P. Cy- 
