Lacock Abbey, near Chippenham
Septr 1st 1835
Having seen in the newspapers a letter of yours concerning Halley’s Comet, <1> I beg to communicate to you an observation I made of it on the 27th ult. with an achromatic of 4 ½ inches aperture, somewhat smaller therefore than the size (6 inches) which you mention as requisite for viewing this object at present.
On August 27 at 14h the comet was close to a bright star from which its difference was estimated,
in A. R. 0
in Decl. 4′
I have been fortunate enough to find an observation of the star in the Hist. Céleste Française <2> (page 315) it being the star which is there set down “passage au fil du milieu 5h 44′ 15,5″ Having calculated therefore as well as I am able the position of the star at present I find
A. R. 5h 46′ 50″
D 24º 13′ 27″
Consequently the position of the Comet Aug. 27, 14h
A. R. 5h 46′ 50″
D 24º 17′ ½
I should be much obliged if you would observe this star & communicate to me its current position, if the one above mentioned deviates from the truth – I do not find in the newspapers any corresponding observation of the 27th – that made at Greenwich being of the 28th. I do not think the above observatn of the comet is likely to be erroneous more than 1′ or 2′, but to make certain I made a sketch of the configuration of the telescopic stars around it, which fix its place very nearly, & which I can observe again at a future time.
I observe it again on the 31st when it had moved about a degree from its former position, but think it unnecessary to add particulars as it is now observed in Several quarters & no doubt with first rate instruments. – It had not augmented in brightness from the 27th to the 31st on the contrary I considered it grown more indistinct; – I saw neither tail nor nucleus, only a hazy nebulous appearance.
I have the honor, to be, Sir, Your obedt Servant
Henry F. Talbot
2. Joseph Jérôme Le Française de Lalande (1732–1807), Histoire Céleste Française Contenant les Observations Faites par Plusieurs Astronomes Française (Paris: Imprimerie de la république, 1801).