Would support the establishment of Colonial magnetic and meteorological observatories if Edward Sabine were to continue to study the observations made [see GA's 1858-1-29].

Sends JH some responses to a letter from Edward Sabine on Colonial observatories [see GA's 1858-3-13].

Reacts to JH's suggestions [see JH's 1858-5-[10]] for altering GA's responses [see GA's 1858-5-4] to Edward Sabine's report on magnetic observatories [includes a silly riddle, apparently passed on from Augustus De Morgan].

Provides a more detailed response to Edward Sabine's report on magnetic observatories [see GA's 1858-5-12].

Has looked at the magnetic observations made at the Cape, and comments on their usefulness.

If magnetic observation stations are to be set up and staffed, then personnel should be considered soon.

Supports JH's intentions [see JH's 1858-6-26] and Edward Sabine's proposals about magnetic observations, but displays little faith in the effectiveness of the B.A.A.S.

Is unhappy with one aspect of Edward Sabine's report [see ES's 1858-6-26], specifically the number of days each year when simultaneous observations will be made at all stations.

Indicates GA's intention of being at the Leeds meeting [of the B.A.A.S.].

Urges JH to attend the next meeting of the Board of Visitors of the Royal Observatory, especially as GA believes some of the members of the Board do not understand the scientific problem [?].

Circular letter advising of the availability of back copies of various Royal Observatory printed observations.

As GA is about to leave on holiday, he brings JH up to date on the state of the nebula calculations [see JH's 1862-5-28].

Does JH need the original calculation sheets to deal with the errors in the nebula catalogue [see GA's 1863-2-23]?

Returns JH's letter from G. G. Stokes about eclipse spectroscopy; GA has written to Stokes as well and encloses a copy of this letter.

Provides JH with best definition that GA has available for the gallon [see JH's 1867-11-3], noting that methods for establishing standards are revised, even if the standards supposedly are not.

Writes to acknowledge receipt of letter [see JH's 1864-11-25], but it will take time to work through JH's calculations carefully.

Thanks JH for his useful letter [see JH's 1867-12-2]; it will be of value to the Commission on Weights and Measures.

Thanks JH for his clear letter [see JH's 1867-12-3] about the pound weight standards.

Proposes a principle for the establishment of musical scales to satisfy musicians, not mathematicians, as JH had apparently done.

More on musical scales [see GA's 1868-4-3]; GA here proposes the use of hyperbolic logarithms to help establish the scales.