94 B.V. Marsh on the Distinguishing Features of Comets. 
From the above table it appears that of the comets of short 
period, all of which are inconspicuous, the highest ratio of the 
time spent in the aphelion to that spent in the perihelion part of 
its orbit is 28, whilst the lowest figure for a comet of any consid- 
erable brilliancy is 283 for that of Halley, and for the great 
comets of 1848 and 1680, the ratios are two millions and forty 
millions respectively. So far then as can be judged from the 
limited data at my command, the proposition that splendor is 
never found without great excentricity is fully confirmed.* _ Itis, 
perhaps, worthy of remark that the asteroid Polyhymnia ap 
proaches in excentricity so near to the comets of short period as 
* Since the above has been in the hands of the printer, I have seen in the North 
British Review for November, 1861, the following notice of a work “On the Phys 
cal ee of Comets. By Olinthus Gregory Downes, F.R.A.S. 4to, pp. 4 
on, 1860,” viz.: 
but of matter. By the issue of jets from the nucleus, Mr. Downes thinks that 
rotatory motion may be produced and periodically accelerated, In this way a 
: 
Sedans on) 
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AFSneapESRRE eS 
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