Encourages RP in his speculations about the nebulae and the structure of the Milky Way, which RP suggested is formed of a 'system of convolutions,' but raises objections to RP's views. Discusses idea that the Milky Way contains miniatures of itself and that beyond it may be a hierarchy of universes comparable to the Milky Way.

Elaborates on his hypothesis that all forms of nebulae are part of the Milky Way and on his 'twisted-stream theory' of the Milky Way's structure. Favors view that dark matter is relatively common in space and that it extinguishes light from distant objects. Proposes method of measuring stellar diameters.

Is trying to get JH 2 copies of Physique sociale. Discusses additions. Addresses JH's comments concerning power of a supreme being. Sends 19th volume of annals of observatory and AQ's work on international congress on statistics.

Apologizes for not acknowledging JH's work. Asks for copy of Royal Geographical Society's papers. Discusses [François] Arago's work on light beams and prisms. Requests JH's opinion concerning [Wilhelm] Klinkerfues's theory of light, which seems to make [Augustin] Fresnel's hypothesis superfluous.

Of the fruit in the garden and the arrival of various of their daughters; JH seems to be feeling a little sorry for himself, but concludes with a riddle in French.

Thanks for second volume of Physique sociale. Happy to see AQ refuting 'the results of statistics of life, accident, crime...[as] indicative of an absence of free agency in human beings and the presence of some sort of impelling necessity.' Mentions JH's daughter's marriage and her learning Chinese.

His letter has been forwarded. JH's correspondence with the Mint to which J. G. Hubbard refers has been published in the Report of the Commissioners on International Coinage 1868. Thinks expansion of mercurial amalgam is due to hydrogen. Hopes JH will accept a small medallion.

Discusses Olbers's Paradox, raises objections to RP's argument for the existence of dark celestial matter, and points out problems in RP's method of measuring stellar diameters.

Sends 'first fruits' of Melbourne telescope in form of a letter from [A.] LeSueur and [R. L. J.] Ellery. Includes discussion of nebulae.

Thanks for notice on first performance of Melbourne telescope and its contributions to knowledge about nature and role of nebulae. Comments on relationship of nebula and apparently associated stars. Looks forward to report on Magellanic Clouds.

Thanks JH for his positive judgement of his work. Mentions that [François] Moigno could only say that it was anti-religious. Another work on statistics has emerged: Versuch einer Sozialethik, 2nd. vol., by Alexander von Ochingen. In few days leaves for international conference on statistics.

Accepts JH's objection to his method of measuring stellar diameters. Quotes an argument he had published suggesting the existence of a hierarchy of systems in an infinite universe. Discusses his studies of the relation of proper motions to the sun's motion. Asks JH's permission to publish JH's idea that some nebulae may be 'miniature' of the Milky Way.

Requests permission to print JH's response approving of fixed-telescope system for time-keeping set out in TW's new book on civil time-keeping, How to Keep the Clock Right.

Is very pleased that JH has accepted his little volume. Is sure JH would have made a success of a similar work. Behavior of animals.

Discusses in detail the then currently debated issue of a 'mintcharge or seigniorage' on gold coinage. Also discusses the idea of an international coinage.