“On Apr. 7th Herschel wrote to me that the Professorship held by Dr Brinkley (then appointed Bishop of Cloyne) at Dublin would be vacant, and recommended it to my notice, and sent me some introductions.  I reached Dublin on Apr. 15th, where I was received with great kindness by Dr Brinkley and Dr MacDonnell (afterwards Provost).  I there met the then Provost Dr Bartholomew Lloyd, Dr Lardner, Mr Hamilton (afterwards Sir W. R. Hamilton) and others.  In a few days I found that they greatly desired to appoint Hamilton if possible (they did in fact overcome some difficulties and appoint him in a few months), and that they would not make such an augmentation as would induce me to offer myself as a candidate, and I withdrew.  I have always remembered with gratitude Dr MacDonnell’s conduct, in carefully putting me on a fair footing in this matter.  I returned by Holyhead, and arrived at Birmingham on Apr. 23rd.  While waiting there and looking over some papers relating to the spherical aberration of eye-pieces, in which I had been stopped some time by a geometrical difficulty, I did in the coffee-room of a hotel overcome the difficulty; and this was the foundation of a capital paper on the Spherical Aberration of Eye-pieces.  This paper was afterwards presented to the Cambridge Philosophical Society.

“About this time a circumstance occurred of a disagreeable nature, which however did not much disconcert me.  Mr Ivory, who had a good many years before made himself favourably known as a mathematician, especially by his acquaintance with Laplace’s peculiar analysis, had adopted (as not unfrequently happens) some singular hydrostatical theories.  In my last Paper on the Figure of the Earth, I had said that I could not receive one of his equations.  In the Philosophical Magazine of May he attacked me for this with great heat.  On May 8th I wrote an answer, and I think it soon became known that I was not to be attacked with impunity.

“Long before this time there had been some proposal about an excursion to the Lake District with my sister, and I now arranged to carry it out.  On May 23rd I went to Bury and on to Playford:  while there I sketched the Cumberland excursion.  On June 5th I went to London, I believe to the Visitation of the Greenwich Observatory to which I was invited.  I also attended the meeting of the Board of Longitude.  I think it was here that Pond’s Errors of the Sun’s place in the Nautical Almanac from Greenwich Observations were produced.  On June 7th I went by coach to Rugby, where I met my sister, and we travelled to Edensor.  We made a number of excursions in Derbyshire, and then passed on by Penrith to Keswick, where we arrived on June 22nd.  From Keswick we made many excursions in the Lake District, visited Mr Southey and Mr Wordsworth, descended a coal mine at Whitehaven, and returned to Edensor by the way of Ambleside, Kendal, and Manchester.  With sundry excursions in Derbyshire our trip ended, and we returned to Cambridge on the 21st July.