“At some time in this term I had a letter from Mr South (to whom I suppose I had written) regarding the difficulty of my telescope:  he was intimately acquainted with Tulley, and I suppose that thus the matter had become more fully known to him.  He then enquired if I could visit him in the winter vacation.  I accordingly went from Bury, and was received by him at his house in Blackman Street for a week or more with great kindness.  He introduced me to Sir Humphrey Davy and many other London savans, and shewed me many London sights and the Greenwich Observatory.  I also had a little practice with his own instruments.  He was then on intimate terms with Mr Herschel (afterwards Sir John Herschel), then living in London, who came occasionally to observe double stars.  This was the first time that I saw practical astronomy.  It seems that I borrowed his mountain barometer.  In the Lent term I wrote to him regarding the deduction of the parallax of Mars, from a comparison of the relative positions of Mars and 46 Leonis, as observed by him and by Rumker at Paramatta.  My working is on loose papers.  I see that I have worked out perfectly the interpolations, the effects of uncertainty of longitude, &c., but I do not see whether I have a final result.

“In Jan. 1824, at Playford, I was working on the effects of separating the two lenses of an object-glass, and on the kind of eye-piece which would be necessary:  also on spherical aberrations and Saturn’s figure.  On my quires at Cambridge I was working on the effects of separating the object-glass lenses, with the view of correcting the secondary spectrum:  and on Jan. 31st I received some numbers (indices of refraction) from Mr Herschel, and reference to Fraunhofer’s numbers.

“About this time it was contemplated to add to the Royal Observatory of Greenwich two assistants of superior education.  Whether this scheme was entertained by the Admiralty, the Board of Longitude, or the Royal Society, I do not know.  Somehow (I think through Mr Peacock) a message from Mr Herschel was conveyed to me, acquainting me of this, and suggesting that I should be an excellent person for the principal place.  To procure information, I went to London on Saturday, Feb. 7th, sleeping at Mr South’s, to be present at one of Sir Humphrey Davy’s Saturday evening soirees (they were then held every Saturday), and to enquire of Sir H. Davy and Dr Young.  When I found that succession to the post of Astronomer Royal was not considered as distinctly a consequence of it, I took it coolly, and returned the next night.  The whole proposal came to nothing.