On June 7th he attended the Visitation of the Royal Observatory.—­From a letter addressed to him by Mr J. Hartnup, of Liverpool Observatory, it appears that there had grown up in the mercantile world an impression that very accurate chronometers were not needed for steam ships, because they were rarely running many days out of sight of land:  and Airy’s opinion was requested on this matter.  He replied as follows on Mar. 3rd:  “The question proposed in your letter is purely a practical one. (1) If a ship is likely ever to be two days out of sight of land, I think that she ought to be furnished with two good chronometers, properly tested. (2) For the proper testing of the rates of the chronometers, a rating of the chronometers for three or four days in a meridional observatory is necessary.  A longer testing is desirable.”—­In March he was in correspondence, as one of the Trustees of the Sheepshanks Fund, with the Master of Trinity relative to grants from the Fund for Cambridge Observatory.

1891

From June 16th to July 15th he was at Playford.  And again from Oct. 12th to Dec. 2nd (his last visit).  Throughout the year his weakness, both of brain power and muscular power, had been gradually increasing, and during this stay at Playford, on Nov. 11th, he fell down in his bed-room (probably from failure of nerve action) and was much prostrated by the shock.  For several days he remained in a semi-unconscious condition, and although he rallied, yet he continued very weak, and it was not until Dec. 2nd that he could be removed to the White House.  Up to the time of his fall he had been able to take frequent drives and even short walks in the neighbourhood that he was so fond of, but he could take but little exercise afterwards, and on or about Nov. 18th he made the following note:  “The saddest expedition that I have ever made.  We have not left home for several days.”

The rapid failure of his powers during this year is well exemplified by his handwriting in his Journal entries, which, with occasional rallies, becomes broken and in places almost illegible.  He makes frequent reference to his decline in strength and brain-power, and to his failing memory, but he continued his ordinary occupations, made frequent drives around Blackheath, and amused himself with his family history researches, arrangement of papers, and miscellaneous reading:  and he persisted to the last with his private accounts.  His interest in matters around him was still keen.  On June 13th he was driving along the Greenwich Marshes in order to track the course of the great sewer; and on August 5th he visited the Crossness Sewage Works and took great interest in the details of the treatment of the sewage.—­In March he contributed, with great satisfaction, to the Fund for the Portrait of his old friend Sir G.G.  Stokes, with whom he had had so much scientific correspondence.—­On July 25th an afternoon party was arranged to celebrate