This book brings together works published between 1846 and 1859 by the Scot James D. Forbes (1809–68) and Irishman John Tyndall (1820–93), both of whom were experienced alpinists as well as glaciologists. However, their views on the motion of glaciers were disparate, and a scientific quarrel over primacy and credit for discoveries continued even after their respective deaths. These papers include Forbes' articles on experiments on the flow of plastic bodies and analogies between lava and glacier flows, and on the plasticity of glacier ice, as well as Tyndall's observations on the physical phenomena of various Alpine glaciers, including the famous 'Mer de Glace', and a piece on the structure and motion of glaciers, co-written with Thomas Huxley. Several works by and about all three scientists (including works on Alpine travel) have also been reissued in this series.