As our Index contains all the corrections and information which I possibly could collect, those corrections and memorandums of which I had the pleasure, about eighteen months ago, to write a copy for Dr. Maskelyne, will consequently be laid aside, else I ought to take notice that there are one or two errors and several omissions which should have been corrected in that copy, but with which it will now be needless to trouble you, sir. What has laid me under particular obligation to you, my dear sir, was your timely information, the August before last, of your having proposed the printing of the Index to the P. R. S. The papers were then in so incomplete a state, that it needed each moment which could possibly be spared from other business to deliver them with some confidence of their being pretty correct. Many times do I think with pleasure and comfort on the friendly invitations Mrs. Maskelyne and yourself have given me to spend a few days at Greenwich. I hope yet to have that pleasure next spring or summer. This last has passed away, and I never thought myself well or in spirits enough to venture from home. If the heavens had befriended me, and afforded us a comet, I might, under its convoy, perhaps have ventured at an emigration. However, I cannot help thinking that I shall meet with some little reward for the denial it has been to me not coming this summer in seeing the improvements Miss Maskelyne has made (more perceptibly) in those accomplishments she seemed to be in so fair a way of attaining when I was there last. With my best respects and compliments to Mrs. M., I remain, with the greatest esteem, Your most obliged and humble servant, C. HERSCHEL. [Sidenote: 1798. _Extracts from Day-book._] DIARY. _May 29th_ and _30th_.—Was mostly spent at the Observatory, Professor Vince[15] being there. _July 30th._—My brother went with his family to Bath and Dawlish. I went daily to the Observatory and work-rooms to work, and returned home to my meals, and at night, except in fine weather, I spent some hours on the roof, and was fetched home by Sprat. * * * * * _September 11th._—Dined at my brother’s. Professor Pictet and Dr. Ingenhouse, &c., were there. Cloudy night. _October 7th._—Finished the MS. Catalogue of omitted stars for Dr. Maskelyne. * * * * * _December 31st._—_Mem._ Uncommonly harassed in consequence of the loss of time necessary for going backward and forward, and not having immediate access to each book or paper at the moment when wanted. [Sidenote: 1799. _Extracts from Day-book._] _January 4th._—Spent the evening at my brother’s. Sir Wm. Watson[16] and Mr. Wilson[17] were there. _February 11th._—My brother went to Bath to make some stay there, having taken a house on Sion Hill.