202 On the Great Comet of 1843. 
the point of observation of the comet’s nebulosity will stand thus, 
being freed from parallax and aberration. 
PRs re gscA PARR TOO 0 Nae ean PY Nev NG) SB IRS EY rs ANE Ne 
Greenwich | Normal ences Correc. |Corrected nor-|Normal ane Correc.|Corrected nor- 
mean time. R.A R. A. |malplace, R.A. Dec, Dec. |mal place, Dec. 
Mar. 204.5 |46° 4! 3877, 4| +0/'.0 |46° 4! 38//.4/-9° 9/ 451.5 5|—5!.4|—9 9! 50/19 
Mar. 30 .5 [59 51 1 2) +9 .5 [59 51 10 .7/-6 36 32 .5|/—5 .2|—6 36 37 .7 
April 9 5 '68 56 41 .6' +0 .0 '68 56 41 .6'-4 45 35 .7!|—0 .0'—445 35 .7 
‘Then the corrections of the ephemeris, computed from our hy- 
perbolic elements, will be 
March 20.5 4a=—0".6; 46=—A".5 
March 30.5 «49.5; “66.2 
April 9.5 c 6 0.6; se +0".3 
These values are so small that a change in the elements of the 
orbit of the point of the nebulosity observed, which should re- 
duce them to zero, would be too small to indicate any change in 
the conclusions already drawn by us from our first normal places. 
Unless, then, further observations shall be obtained from the 
southern hemisphere previous to the perihelion passage, we see 
no way of avoiding the conclusion that the point of the nebu- 
losity observed was moving in an hyperbola, with a mean daily 
motion of about 160”, which in a curve having a periodical char- 
acter, would give a duration of a revolution of about 22 years, 
with elements, as far as we know, identical with those of the 
comets of 1668.2 and 1689.9. 
We subjoin from Pingré’s Cometography a list of comets that 
have appeared at dates when this comet, if it be the same as 
those of 1668.2, and 1689.9, must have been in a situation to 
be seen from some part of the earth. It must be recollected that 
this comet can never have come to its perihelion in the months 
of November, December, January and February, without being 
a conspicuous object in the morning or evening twilight, before 
or after the passage of the perihelion. In all instances it must 
have been best seen in the southern hemisphere. We have 
given nearly all the coincidences in dates. ‘Those which have 
no (*), nor (?) annexed are coincidences in date. ‘Those marked 
with an (*) have, besides the coincidence in date, some circum- 
stance, whether of physical appearance or apparent path in the 
heavens, analogous with the comet of 1843. Those marked 
with an (?) are probably mere coincidences in date without being 
the same individuals. 
