Copy letter, from Sir John Herschel to Wilhelm Struve, dated at Slough Copy of a letter. Confirms receipt of Wilhelm Struve's last letter from Hamburg. Advises of his departure to Cape. Requests 'measure of 3000 double stars.' Directs Wilhelm Struve's attention to 'remarkable stars' and urges Wilhelm Struve to procure John Frederick William Herschel's Astronomy. Asks Wilhelm Struve to solicit [F. W.] Bessel's correspondence for John Frederick William Herschel. Adds [W. H.] Smyth's address. 29 October 1833