The collection consists of log books, letter books, letters, and documents preserved by John Elphinston, rear-admiral in the service of Catherine the Great. Includes his certificate of service signed by the Empress Catherine; his unpublished manuscript memoirs (1773) in four volumes; a narrative of the Russian expedition by sea (1769-70), with an account of his reception at the Court of St. Petersburg and his meetings with Catherine the Great, who had asked the British government to loan her some senior naval officers to rehabilitate the Russian fleet; and Elphinston's own letter book and log book for the expedition. There are also manuscript narratives of the expedition edited by his grandson Captain Alexander Elphinstone; petitions to the Russian Emperors Alexander (1777-1825) and Nicolas (1868-1918) for the reward due to his grandfather; and autograph letters in English, French, and Russian; and a 1780 mezzotint of the admiral.