Journal of a voyage in Baffin's bay and Barrow strait, in the years 1850-1851, permorfed by H. M. ships Lady Franklin and Sophia, under the command of Mr. William Penny, in search of the missing crews of H. M. Ships Erebus and Terror: with a narrative of sledge excursions on the ice of Wellington channel; and observations on the natural history and physical features of the countries and frozen seas visited