Thanks PT for papers on energy. Discusses topics of the papers, including quaternions and the concept of heat equalling motion.

Has copied out some extracts from his translation of Homer and is wondering whether to publish the first twelve books. Comments on his views and poetry of Alfred Tennyson (1st Baron Tennyson).

Thanks for the diary and pocket book. Sees that A. V. Guillemin has published an illustrated Astronomy [Le ciel (Paris, 1864)]. Thinks there is scope for publishing a volume of engravings of astronomical objects. Gives his own idea for the construction of a photometer.

Calling his attention to one of his own articles. Concerning Mr. Magers and Roger Boscovitch's views. Concerning Magellanic Clouds.

Comments about translating Homer and about other translations appearing.

Received Indian survey chart. JH's son John wrote of higher-order ellipsoidal triangles with sides based on geodesical triangles. JH objects that these violate principle of diagonal bracing. Proposes different triangles and names sites in India as apexes. Received G. B. Airy's paper on reduction.

Thanks for the valuable series of measures of double stars. Regarding JH's method of calculating the orbit of a double star, which RE seems to have misunderstood.

Gives CB permission to publish the portions of letters requested by him. JH tells CB that he has responded to John Davy's letter in the PM.

As JH has been approached by Charles Babbage for permission to publish certain portions of JH's correspondence, JH is writing to say that he gives both Babbage and JS permission to publish what they will.

Attempts to clarify claims published by John Davy concerning whether his brother Humphry Davy had in 1827 promised Charles Babbage a position as secretary of the R.S.L.

Comments on WS's publication on sidereal chromatics. Believes validity of doctrine of three primary colors proved.