Discusses methods of magnetic observation, JH's actinometric readings in the Cape, and the need for more physical observatories.

Thanks for medal of the Royal Society of Edinburgh.

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].

Comments on JF's article about glaciers and particularly on the solid, liquid, and other states of matter.

Expresses thanks for several of JF's writings and relief at JF's good health. Comments on JH's own writing.

Outlines theory behind and method for preparing thermographic paper, which allows observers to determine 'what share each ray of the spectrum bears in producing the observed total effects.'

Sets up approximate meeting time, depending on his family's timely departure to Antwerp, with JF at the R.S.L. apartments.

Calls JF's attention to an article in which an answer is attempted to JF's objection to 'the argument from probability of a physical connection between individuals of a double star.'

Requests information about actinometers in JF's possession, and provides further information regarding their use.

Believes all actinometric measurements made are useless because they did not take into account the rate of expansion of the liquid, which is not constant.

Sends thanks and congratulations for paper verifying electric origins of all magnetism. Will give JF an actinometer with complete instructions. Includes some instructions for obtaining and using it. Sends regards to Mario Gemellaro, should JF go to Catania.

Writes 'in haste' to thank JF for a pair of papers. Comments on Louis Daguerre's pictures in Paris.

Thanks JF for second edition of work on the Alps. Praises first edition.

Expresses appreciation for JF's publication on glaciers.

Suggests that JF use his instruments to compare the force of solar radiation at high and low elevations. Delineates possible methods for this experimentation, and lists results of similar experiments. Includes further information on the actinometer.

Congratulates JF on obtaining, after some difficulty, the Chair of Natural Philosophy at Edinburgh. Accepts offer to discuss meteorology with JF's relation Leslie Melville[?], and hopes to mention his actinometer.

Discusses reduction of barometric observations. Praises the Cape's climate.

Wishes JF well in [Edinburgh] and leaves addresses where JH may be reached [at the Cape].

On the preparation of paper to exhibit a thermal spectrum.

Hopes to add JF's name to B.A.A.S. Meteorological Committee, and to see JF at Cambridge meeting of the committee.