tions. On
Aug. 20th I went to Woodford to see Messrs Gilbert's optical
works. From Aug. 13th I had been preparing for the discussion of the
Greenwich Solar Errors, and I had a man at work in my rooms, engaged
on the calculation of the Errors. I wrote to Bouvard at Paris for
observations of the sun, but he recommended me to wait for the Tables
which Bessel was preparing. I was busy too about my Lectures: on
Sept. 29th I have a set of plans of printing presses from Hansard the
printer (who in a visit to Cambridge had found me making enquiries
about them), and I corresponded with Messrs Gilbert about optical
constructions, and with W. and S. Jones, Eastons, and others about
pumps, hydraulic rams, &c. On Sept. 25th occurred a very magnificent
Aurora Borealis.

"I do not find when the investigation of Corrections of Solar Elements
was finished, or when my Extracts from Burckhardt, Connaissance des
Temps 1816, were made. But these led me to suspect an unknown
inequality in the Sun's motion. On Sept. 27th and 28th I find the
first suspicions of an inequality depending on 8 x mean longitude of
Venus--13 x mean longitude of Earth. The thing appeared so promising
that I commenced the investigation of the perturbation related to this
term, and continued it (a very laborious work) as fast as I was able,
though with various interruptions, which in fact were necessary to
keep up my spirits. On Oct. 30th I went to London for the Board of
Longitude meeting. Here I exhibited the results of my Sun
investigations, and urged the correction of the elements used in the
Nautical Almanac. Dr Young objected, and proposed that Bouvard should
be consulted. Professor Woodhouse, the Plumian Professor, was present,
and behaved so captiously that some members met afterwards to consider
how order could be maintained. I believe it was during this visit to
London that I took measures of Hammersmith Suspension Bridge for an
intended Lecture-model. Frequently, but not always, when in London, I
resided at the house of Mr Sheepshanks and his sister Miss
Sheepshanks, 30 Woburn Place. My quires, at this time, abound with
suggestions for lectures and examinations.

"On some day about the end of November or beginning of December 1827,
when I was walking with Mr Peacock near the outside gate of the
Trinity Walks, on some mention of Woodhouse, the Plumian Professor, Mr
Peacock said that he was never likely to rise into activity again (or
using some expression