Comments on JH's work on nebulae and offers some of his own nebula observations. HA would be greatly honored if JH would include HA's observations in the catalog JH is preparing.

Thanks for acknowledging his mathematical memoir. Intended his paper on polyhedra for the French prize, but was annoyed they would not recognize his work, so submitted it to the R.S.L. instead. Is sending a paper to William Cavendish (7th Duke of Devonshire), who is a mathematician.