Letter, from Francis Beaufort to Sir John Herschel, dated at Admiralty Autograph letter signed by sender. On Friday the compensating bars will be embarked for the Cape; William Mann will be in charge of them at the Tower. Dr. T. R. Robinson is anxious to have some of the instruments from the Kew Observatory; does John Frederick William Herschel know how they may be obtained? Regarding an actinometer made by Robinson. 17 July 1839