"Glaciers of the Alps" was published nearly six and thirty years ago, and has been long out of print, its teaching in a condensed form having been embodied in the little book called "Forms of Water." The two books are, however, distinct in character; each appears to me to supplement the other; and as the older work is still frequently asked for, I have, at the suggestion of my husband's Publishers, consented to the present reprint, which may be followed later on by a reprint of "Hours of Exercise." Before reproducing a book written so long ago, I sought to assure myself that it contained nothing touching the views of others which my husband might have wished at the present time to alter or omit. With this object I asked Lord Kelvin to be good enough to read over for me the pages which deal with the history of the subject and with discussions in which he himself took an active part. In kind response he writes:--"... After carefully going through all the passages relating to those old differences I could not advise the omission of any of them from the reprint. There were, no doubt, some keen differences of opinion and judgement among us, and other friends now gone from us, but I think the statements on controversial points in this beautiful and interesting book of your husband's are all thoroughly courteous and considerate of feelings, and have been felt to be so by those whose views were contested or criticised in them." The current spelling of Swiss names has changed considerably since "Glaciers of the Alps" was written, but, except in the very few cases where an obvious oversight called for correction, the text has been left unaltered. Only the Index has been made somewhat fuller than it was. L. C. T. _January, 1896._ CONTENTS. PART I. Page 1.--Introductory. 1 Visit to Penrhyn; the Cleavage of Slate Rocks; Sedgwick's theory--its difficulties; Sharpe's observations; Sorby's experiments; Lecture at the Royal Institution; Glacier Lamination; arrangement of an expedition to Switzerland 2.--Expedition of 1856: the Oberland. 9 Valley of Lauterbrunnen; Pliability of rocks; the Wengern Alp; the Jungfrau and Silberhorn; Ice avalanches; Glaciers formed from them; Scene from the Little Scheideck; the Lower Grindelwald Glacier; the Heisse Platte--its Avalanches; Ice Minarets and Blocks; Echoes of the Wetterhorn; analogy with the Reflection of Light from angular mirrors; the Reichenbach Cascade; Handeck Fall; the Grimsel; the Unteraar Glacier; hut of M. Dollfuss; Hotel des Neufchatelois; the Rhone glacier from the Mayenwand; expedition up the glacier; Coloured Rings round the sun; crevasses of the _neve_; extraordinary meteorological phenomenon; Spirit of the Brocken