Henry Herbert Mackarsie was born in or around the 1810's or 1820's and died May 12, 1857 at Monte Video, Uruguay on board HMS Indefatigable after having been removed from HMSS Rifleman on May 7th. Mackarsie was a surgeon in the Royal Navy having served on the Steam Sloop Growler under Commander Patbury from April 1847 to March 1848, the HMS Dover in September 1848, the the Alert and the Sea Lark. In 1849 he transferred to HMS Spy off the west coast of Africa and then to HMS Steamer Rifleman in 1855. Mackarsie was married to Elizabeth Cock, daughter of Elizabeth Greig Currie and Robert Cock. This collection is comprised of Mackarsie's personal diary kept on a daily basis that commences April 24th 1855 "continued from the other book" ( the other book is not present) aboard HM Steamer Rifleman at Corrientes. It runs to May 7th 1857 where it ends in mid page, with several blank pages remaining. Mackarsie describes the numerous comings and goings of senior officers, visiting officials, civilian visitors and his daily activities. The geographic range of the Ship seems to be along the east coast of South America, mainly in the River Plate estuary with side trips to Rio de Janeirio.