On the Great Comet of 1843. 201 
 itisite by the method of least squares. ‘The elliptic elements 
should of course be used in computing perturbations. 
We have the honor to be your obedient servants, 
gars C. WALKER, 
E. Oris Kenpauu. 
To Messrs. John K. Kane, Alexander Dallas Bache, LL. D., 
Robley Dunglison, M. D., Joshua Francis Fisher. 
High School Observatory, Philadelphia, June 16th, 1843. 
To THES ' oF THE AMERICAN PurnosopHicaL Society. 
Gentlemen—Since writing the letter which was read at the 
centennial meeting of the Society, we have compared our normal 
places of the comet on the 20th and 30th of March with the Euro- 
pean observations. We have not been able to find any later than 
the 31st of March, and must still rely on our own measures for the 
comet’s place on the 9th of April. In order to test the normal 
places for March 20th and 30th, we subjoin the differences there- 
from of the European observations referred to the date of Green- 
wich mean midnight, after rejecting two in all, whose discrepan- 
cies from the mean result exceeded ay seconds of space. 
Observation compared ~~, Correction of jorrection o Date of normal | 
with "| normal place, ha: ' normal me wth a 
: iT ro. ye Mz : } i Eat 
ca tee pies 
an See: 
Port hspeary 2 
ad hi cat 
March 30.5 
Mean correction, | -+10".7 — "0 
I i cos seer Reinstabne cob 
If we allow to the High School observations the same weight 
as that of one European he then the normal places of 
* ‘Vol. xtv, No. 1.—April-June, 1843. 
