Sir
In reply to your note of the 6th inst. I beg to acquaint you that in the only Ephemeris of the Comet<1> I can now lay my hands on, the places are not give [sic] for the 10th, 20th, or 30th, instant. The nearest to these days are as follows, or rather the following are the places for 4 equidistant periods of fo eight days
| R.A.<2> | Dec.<3> | Meridian | Passage (Greenwich) | |
| Aug 11 | 5h 31m·43 | 23º 22º·2 | 20h 12” | 12 mins |
| 19 | 5 38 ·72 | 24 14 ·3 | 19 48 | |
| 27 | 5 46 ·62 | 25 21 ·1 | 19 24 | 10½ mins |
| Sept 4 | 5 55 ·80 | 26 53 ·7 | 19 2 |
The above is taken from the Nautical Almanac for 1835<4> where further information will be found
The appearance of the comet will most probably be notified in the newspapers before it reaches the Society.<5>
I remain Sir Your obedt Servt
A De Morgan
Somerset House
August 7/35
[address panel:]
H. F. Talbot Esq F.R.A.S.
Lacock Abbey
near Chippenham
Notes:
1. Halley’s Comet.
2. Right Ascension.
3. Declination.
4. Nautical Almanac for Astronomical Ephemera (London: The Lord’s Commissioners of the Admiralty, 1833), p. 489.
5. De Morgan was Vice President of the Royal Astronomical Society, then based at Somerset House, London.