192 On the Great Comet of 1843. 
of a rebound, or of the comet’s flowing round the sun, we waited 
for the opinions of our friends, and for further information from 
the European observatories. We have since received both, and 
hasten to lay them before you. First, the arrival of the Caledo- 
nia brought out the announcements from most of the Kuropean 
observatories in Prof. Schumacher’s excellent Astronomical Noti- 
ces of April 22. From these it appears that the comet’s nucleus 
was first seen in Europe, at Nice on the 14th, and first observed 
at Rome on the 17th of March. This was five days later than 
it was observed at several places in the United States, viz. on the 
Oth and 11th, not to mention Mr. Clarke’s measures of the dis- 
tance of the nucleus from the sun on the 28th of February. 
The latest observation quoted by Schumacher, is that of Encke 
at Berlin, March 31st. Perhaps it was seen later. We follow- 
ed it at the High School Observatory till the 10th of April. 
The conclusion of Encke, Steinheil, Nicolai, Schumacher, Ar- 
gelander and others, that the parabola is not the true conic sec- 
tion for this comet, confirmed the announcement we had made 
on the 11th April. Encke who alone of all the astronomers yet 
heard from, had discussed the question of the particular conic sec- 
tion, had found an hyperbola resembling ours, with the perihelion 
point just falling outside of the sun. Thus one of our paradoxes, 
that of the hyperbolic orbit of the observed centre of the nebu- 
losity, was confirmed by the only astronomer in Europe, who as 
far as heard from had gone over the same ground with ourselves. 
For the other paradox, viz. a perihelion point within the body 
of the sun, we find the most ample confirmation. This element 
is thus stated by the European astronomers : 
Plantamour, Geneva, © - - - 0.0045 
Arago, Paris, - - - - 0.0054 
Galle, Berlin, - - - - 0.0118 
Argelander, Bonn, - - - 0.0072 
Nicolai, Manheim, - - - 0.0037 
Encke, Berlin, = - - - - 0.0047 or less. 
Do. do. - - - - 0.0036 . 
Do. do. - - - - 0.0052 hyperbola. 
Mean, - - - - - 0.0057 
Do. omitting Galle, - - - 0.0049 
Our last result, - - - - 0.0041 hyperbola. 
Sun’s semidiameter, - - - 0.0047 
