4 Observations of the comet of 1807. 
entioned, that these elements were very different from those of uaty: 
of He known comets, published by De La Lande in‘his astronomy: 
For a third approximation I combined the observations of October 
and November in ten examples similar to the last, and thus procured 
twenty equations like those given by La Place in vol. i. pag. 229, 
‘* Mecanique Celeste.” From the mean of these the corrected ele- 
ments were found as follow. 
_ Perihelion distance 2ESH Mies BY Dae 6485 
: kseroP beladagialdophathdieiy : pow Sep 18d): 12h.- 
‘Place of the perihelion counted on the feo bp Qs. o 5 se | 15" 
of the-cometis 287..960-30--4aa, Seay 
icone of - ei node a N=8 26 36 29. 
See ee aR até 
Sone: 
ecliptic... I=63 15 Sl. 
ments were found in general not to differ more Sandee minutes = fron 
the observations in September, October, and November. To obtain. 
a greater degree of accuracy I made use of the following method. 
I supposed the corrections to-be applied to the preceding elements: 
to be represented by 0,002.d, 0,2.t, 10'.p, —10'.,—10'., which 
would make the corrected elements sapeoaninad CREE 
D+0,002:d 
T +0,2 -¢ 
oe fe ee 
‘N—10'+ 2 
1—10'-% 
and then calculated the values of d, t, p,m, and 7, in the following- 
manner. 
First supposition. Making u use of the elements D, T, P, N, and I, 
I calculated to seconds by Taylor’s S logarithms, the geocentric longi- 
tude and latitude of the comet for each of the observations contained 
in the following table from October 8 to December 17. Denoting, 
