Board of Longitude will accomplish nothing by meeting before T. M. Brisbane comes to town, but TY suggests informal discussion, either at TY's or Henry Kater's.

Henry Kater not well [enough to travel] and requests committee meet at Kater's house. TY urges JH to verify W. H. Wollaston's measurement of refraction before republishing JH's essay. Diagrams Christiaan Huygens's principle of refraction. TY is making forms of aplanatic lenses.

Writes CB at Naples to inform CB that CB has been elected Lucasian Professor at Cambridge. Urges CB to write to thank the electors.

Charles Babbage has been elected to Cambridge's Lucasian professorship. Thanks JH for his efforts. Hopes Babbage will fill it effectively.

Sending the Memoires of the Académie.

Thanks for fourth volume of "English Flora". Intends to stay in London till the Linnean Society anniversary meeting as the meetings of other societies and London dining hours are too late. Death of Daniel Moore FLS of Lincoln's Inn. Astonished by sudden disappearance of Mr Simmons of Paddington House, wonders if his flight was caused by ruinous speculation; recalls that Sir William Adams [(1783-1827)] the oculist committed suicide after being ruined by speculating in Mexican mines. Mrs Cullum possibly return to England with his son this summer.

A note at the end states that this letter was erroneously dated Monday 17 April 1828; it should have been written 17 March 1828.