3.--The Tyrol. 23 Kaunserthal and the Gebatsch Alp; Senner or Cheesemakers; Gebatsch Glacier; a night in a cowshed; passage to Lantaufer; a chamois on the rocks; my Guide; the atmospheric snow-line; passage of the Stelvio; Colour of fresh snow; Bormio; the pass recrossed by night; aspect of the mountains; Meran to Unserfrau; passage of the Hochjoch to Fend; singular hailstorm; wild glacier region; hidden crevasses; First Paper presented to the Royal Society 4.--Expedition of 1857: the Lake of Geneva. 33 Blueness of the water; the head of the Lake; appearance of the Rhone; subsidence of particles; Mirage 5.--Chamouni and the Montanvert. 37 Arrival; Coloured Shadows on the snow; Source of the Arveiron; fall of the Vault; "Sunrise in the Valley of Chamouni;" Scratched Rocks; quarters at the Montanvert 6.--The Mer de Glace. 42 Not a _Sea_ but a _River_ of ice; Wave-forms on its surface; their explanation; Structure and Strata; Glacier Tables; first view of the Dirt Bands; influence of Illumination in rendering them visible; the Eye incapable of detecting differences between intense lights 7. 46 Measurements commenced; the "Cleft Station" at Trelaporte; Regelation of snow granules; two chamois; view of the Mer de Glace and its Tributaries; _Seracs_ of the Col du Geant; Sliding and Viscous theories; Rending of the ice; Striae on its surface; White Ice-seams 8. 57 Alone upon the glacier; Lakes and Rivulets; parallel between Glacier and Geological disturbance; splendid rainbow; aspect of the glacier at the base of the Seracs; visit to the Chief Guide at Chamouni; Liberties granted 9.--The Jardin. 61 Glacier du Talefre; Jardin divides the neve; Blue Veins near the summit; surrounding scene; Moraines and Avalanches; Cascade du Talefre; dangers on approaching it from above 10. 64 Lightning and Rain; Spherical hailstones; an evening among the crevasses; Dangerous Leap; ice-practice; preparations for an ascent of Mont Blanc 11.--First Ascent of Mont Blanc (1857). 68