Thanks TM for restoring JH's micrometer.

Has recently been too ill to write. Sent portraits of William Herschel to Wilhelm Struve, Heinrich Schumacher, Karl Gauss, Friedrich Bessel, and others.

Thanks JH for meteorological observations and tells how he will apply them to predictions for Calcutta. Describes need to correct barometer observations. Compiles and compares barometer reading from points of India and Central Asia. Thanks JH for double star observations, which he sends to Madras Observatory.

Discussion of his latest experiments on polarization.

Is enclosing some accounts of the eclipse of the sun. The St. Helena instruments have arrived. Some observations are going to be made in Upper Canada. G. B. Airy proposes some extensive magnetic observations at Greenwich. Is going to Greenwich to see and plan extension to the observatory.

Basil Hall has just brought in the accompanying work of J. B. Biot. Sends another batch of Met. Obs. Is pleased with the success of JH's lunar discoveries.

Returns title deeds JH sent to HW for transfer of land [see HW's 1836-4-7]. Forwards cancelled 'Bond in favor of Neethling' for £150.

WW's results regarding tidal observation and theory. Requests further data from the Cape. Has nearly completed his history of the inductive sciences.

Making such slow progress that he fears the paper may not reach her in time, so will send a duplicate. The paper is longer than intended but it may be altered as desired. Remembers his days at the Cape with pleasure.