Explains efforts at using a makeshift apparatus for 'fixing the spectrum.' Discusses current confusion and ultimate hope surrounding JF's meteorological recommendations. In a postscript, notes observations of meteors in Persei.

Instructions for preparing liquid for the actinometer. Describes 'very strange' experiments on the spectrum as well as an 'unusual' cloud formation.

Requests papers relative to a preface to the catalogue of [N. L.] Lacaille's stars, so that the catalogue may be printed.

Believes JH expressed support for pension for surviving child of Thomas Henderson. Comments on this, stating his own view that she is already well provided for.

Discusses prospects for meteorological committee of B.A.A.S., on which they both will serve. Lacks time for it. Does not need hourly observations made by Committee of Physico-Mathematical Society of Edinburgh.

Gives JF permission to use JH's letter to JF's brother in any way JF sees fit to obtain the Chair of Natural Philosophy (at Edinburgh), but still does not wish directly to promote JF's selection. Briefly discusses results of JF's experiments with the actinometer.

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.