Wishes JH well at the Cape; describes some of his current observations.
Wishes JH well at the Cape; describes some of his current observations.
Welcomes JH back from Cape; includes results of FB's work on geodesical measurements in East Prussia.
Announces the measurement of the annual parallax of 61 Cygni.
Responds to concerns about effect of temperature on measurement of stellar parallax [see JH'S 1838-10-24]; comments on other observations.
Sending JH some writings on geodesic measurements; reports the second measurement of annual parallax of 61 Cygni; comments on some other observations.
Requests FB to send JH any observations of Gamma Virginis made by FB. Anxious for these because of differences between JH's and Wilhelm Struve's measurements of Gamma Virginis. Provides JH's new determination of the orbital elements of this object. Thanks FB for publications FB sent. JH's brother-in-law, J[ames Calder] Stewart, may visit FB.
FB's letter of 4 July 1834 reached JH in March 1835. Discusses the observability of the sixth and seventh Saturnian satellites. Meteorological observations at sea, at Cape, and from Calcutta lead JH to suspect 'annual transfer of atmospheric pressure' between hemispheres and permanent depression at equator. Describes JH's work at the Cape. Praises Thomas Maclear.
Thanks FB for letter in which FB announces the discovery of annual stellar parallax; JH questions whether effects of temperature have been adequately considered.
Thanks FB for a variety of observational material, including establishment of standards of measurement [letter completed 1840-1-3].