Asks GA if he knows of any rules or pitfalls in calculating time from earlier times [even B.C.] to the present.

Needs to revise Outlines Astr., and will include Ernesto Capocchi's announcement of the discovery of another planet; some further corrections of JH's double star paper.

Responds to GA's 1849-4-4, and sends the key.

Is making a case for JH's priority claims with regard to the means of determining double star orbits, in conflict with Yvon Villarceau.

Has passed YV's memoirs on the calculation of orbits on to G. B. Airy for publication; copies will be sent [see YV's 1849-4-1]. Notes that YV's methods are similar to those of U. J. J. Leverrier.

Extended comments about some of GA's statements in GA's abstract of Yvon Villarceau's papers on double stars [see GA's 1849-4-11].

Approves of James Nasmyth's application to join R.S.L. Describes good points of Nasmyth's telescope. Supposes that if he had drawing talent, he would sketch the members of the R.S.L.

Comments on JH's Treatise Astr. in the Cabinet Cyclopaedia, mentioning its continued publication, misstatements he wishes to correct, and his addition of A. de Gasparis's newly-discovered planet [Hygeia].

Family news, questions of son Willy's position, frost in the garden, and JH met Louis Philippe.

A number of copies of the Cape Results were sent out, including one to Charles Ludwig Littrow [see GA's 1849-6-22]; JH will now try to trace the books whereabouts.

Invites CW to come out to Collingwood next week when some other friends are coming, too.

Is pleased CW is coming [see JH's 1849-6-29]; JH asks CW to bring some of his apparatus to do polarized light experiments.

Efforts by Duncan Stewart to provide new career for brother Peter Stewart, whose mischief created economic ruin, left Duncan Stewart in difficult financial situation. JH is willing to relinquish EM's appointment to Haileybury College for JH's son John and to seek position for John at [Royal Military Academy,] Woolwich, if EM would transfer recommendation to Haileybury from JH's son John to Duncan Stewart's second son.

Thanks for present of Thomas Wright's books [An Original Theory of the Universe, 1750]. Finds it curious. Suggests that it is conceptually as distant from 1849 as the ancients were from it. Praises printing of its plates.

Will forward WB's report on Kew Observatory to [John] Taylor. Praises WB's thoroughly inductive discussion of atmospheric electricity.

Comments favorably on report by W. R. Birt on Kew meteorological observations. Sees special significance concerning atmospheric electricity.

Certain that JH did not receive WB's 'Sheet of Curves.' They may be in Edward Sabine's or WB's own possession.

Returns a letter from Thomas Maclear to FB, and then JH expresses his concern about the state of health and work of Maclear.

Raises an objection to a method of calculating probabilities set out by AD in his Formal Logic [1847]. Otherwise, praises AD's discussion.

Encloses star observations. Comments on his instrumental system. Cannot find the rule for position when two stars are of equal magnitude. Neptune with the convicts is anchored in Simon's Bay, awaiting the answer from H. G. Grey (3rd Earl Grey).