Wishes JH would lay hands on the memorandum concerning the Zenith observatory on Etna. Explains why JH's theories regarding a point in gunnery do not work in actual practice. Queries the measurement given by JH for the height of Etna.

Regarding the correct figure for the height of Etna, W. H. Smyth favors the half foot measurement. Regarding falls of stones from Vesuvius. Encloses calculations made by professor at Naval College. Remembers large balls of lava at Teneriffe.

Took the chair at a meeting of the Committee for Physics at the R.S.L. Is to bring the matter before Council, who in turn will request the Master of Ordnance to publish the observations. Material from each observatory will require about half of a quarto volume.

Forwards papers relating to the Aden Observatory; please return, with any comments, to Col. W. H. Sykes. Submits suggestions for monthly information and comments on various topics.

John Murray transmitted JH's note regarding his review of William Whewell's book. Wonders if this letter has been acknowledged. Would like the paper as soon as possible.

Wishes he had communicated direct with JH regarding his article on William Whewell's History of the Inductive Sciences. Could not put it in the present number, but if any part of the article has been written please send it to their printer.

About the urgent need to prepare a report on the magnetic observations, and that HL is the most logical person to give direction to it.

Arrived in Zwartland in September. Surveyed grounds; measured baselines. Will be absent from observatory until Zwartland work finished.

Writes about HP's observations relating to the 'Law of Storms.'

Thanks for [?]'s note and enclosed sonnet. Sorry that old church was replaced during JH's absence from England.

Sending copy of first volume of HR's work on navigation [Practice of Navigation].

Thanks JH for letter introducing Mr. Burnet at the Cape. The Hudson Bay Company is recording the temperature of the subsoil at JR's request. Sends some findings, which he will publish.

Consults JH before responding to Wilhelm Weber's proposal for publication of observations. ES proposes to publish German data with data from Toronto, St. Helena, the Cape, and Van Diemen's Land. The Physical Committee of the R.S.L. suggests strengthening Adolphe Quetelet's application to the Belgian government for magnetic observations. The Hammerfest [Norway] magnetic curve does not harmonize with European ones.

Has JH any special instructions for [Louis] Agassiz's actinometers? Has sent Wilhelm Weber recent data for Toronto and St. Helena observatories while requesting Göttingen lunar observations. Discusses publication of the German Magnetic Association. Seeks advice on the inclusion of a translation of JH's paper on photometric apparatus. Has left at the R.S.L. a copy of C. F. Gauss's and Weber's magnetic atlas.

Has received papers from Colonel Sykes. Describes (and includes a portion of) Lieutenant [Henry] Yule's report on broken instruments, which have prevented operations at Aden [?]. Suggests appointing a director there. Notes safe arrival of instruments at Toronto.

Encloses letter to JH on magnetic survey in Canada and two letters from Leipzig, as well as proposals for reforms in B.A.A.S. Hopes to meet JH at the upcoming anniversary of the R.S.L.

Thanks for letting JH know about honor accorded at 'the Anniversary' [Meeting]. Offers condolences on JL's 'late severe loss.'

JH and family are beginning to feel at home at Collingwood.

Does not know anywhere that such processes as RH uses are used for registry work, although the idea is frequently raised.

Further observations on David Brewster's experiments. On heliometers. Observations on suggestions for Standards.