JH concerned not so much that a few copies of the print of JH's portrait may have been sold, but that the plate itself may have been stolen and sold. Seems relieved to know that the plate was left with the printer, not the engraver. Asks RS to make an inquiry with the printer.

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.'

Tells WT about JH developing the thermographic paper which is susceptible to 'calorific' and 'chemical' rays of light.

No summary available.

Comments on several different reports; also on some experiments that lead JH to think much of the radiant energy of the Sun is absorbed in the atmosphere.

Announces King's enrollment as patron of R.A.S. Recalls Danish monarches who promoted astronomy. Praises Altona observatory and work of H. C. Schumacher.

On the preparation of paper to exhibit a thermal spectrum.

JH has apparently insulted JL by crediting JL's colleagues but not JL with improvements in lunar and planetary theory. JH explains how this happened, that JH's good intentions went awry.

Four appointed directors sent to Cape schools. Will leave Slough in two weeks for Collingwood. Laid William Herschel's telescope to rest at Slough.