6a 
Dr. Brinkley's elements of 
allowance for the unavoidable difficulties under which they 
must have observed. 
Note. — The computations relative to the comet observed 
by Captain Hall, were finished in the middle of October last, 
and the results immediately sent to London for the purpose 
of being laid before the Royal Society. The second part of 
the Transactions for 1821, did not reach me till after the 
communication had been read at the Royal Society. In that 
second part, I was much surprised to find the elements of 
the same comet computed by Mr. Rumker, from the obser- 
vations made by Dr. Olbers, before the passage through 
perihelion. 
Subsequently, the “ Conn, des Terns/’ for 1824, reached 
me, which contains Observations made at Paris, and Elements 
by M. Nicollet ; also a notice of the comet having been ob- 
served in several places of Europe. It certainly is highly 
creditable to those observers who discovered, under very 
difficult circumstances, the comet in its approach to the sun. 
By the addition of Captain Hall*s observations after the 
passage through perihelion, we are enabled to obtain very 
exact elements. 
The errors of my Elements, when applied to observations 
before perihelion, and the errors of Mr. Rumker’s and of 
M. Nicollet’s Elements, when applied to Captain Hall’s 
observations after perihelion, are considerable: 
Therefore, I have farther corrected my Elements, by using 
Dr. Olbers’ observations of January 30, with those of Cap- 
tain Hall of April 8, and May 3. 
