Captain T.C. Tilly's log book dating from April 1850 (with a hand drawn plan of the steam guard Ship 'Blenheim'). Nine days later he transfers temporarily to the 'Birkenhead', then the log resumes aboard the 'Blenheim' until December 1851 when he transfers to 'H.M.S. Britannia' for approximately one year, the book ends aboard the paddle Steamer 'Shearwater' amongst the Ionian Islands. Includes two charts of the area