ABSTRACT
John Herschel saw stars suddenly three times as bright as before, and a fortnight later, it was nearly the third brightest in the sky. Stellar parallax was still being diligently sought, Piazzi, Brinkley, and others claiming success which Bessel at Konigsberg and Pond from the Greenwich observations were unable to confirm. Great achievement of Bessel's was the discovery of the orbital motion of the two Dog-stars, Sirius and Procyon, which, in 1844, after a very refined series of measures, he pronounced to be revolving about dark or relatively dark companions. The origin of double star astronomy, a field entered with avidity by the celebrated Struve as soon as he was equipped with the great Dorpat refractor. Herschel's work required completion for the southern sky, and even in the northern part the extensive field in which he laboured did not seem to attract a successor among the leading astronomers of the time.
