The Glaciers of the Alps. John Tyndall
meaning; Facts and Principles; definition of theory; Some Experiments on the Mer de Glace to test the Viscosity of the Ice
Caused by the Motion; Ice Sculpture; Fantastic Figures; beauty of the crevasses of the highest glaciers; Birth of a crevasse; Mechanical Origin; line of greatest strain; Marginal Crevasses; Transverse Crevasses; Longitudinal Crevasses; Bergschrunds; Influence of Flexure; why the Convex Sides of glaciers are most crevassed
18. 325
Further considerations on Viscosity; Numerical Test; formation of crevasses opposed to viscosity
Connexion of Natural Forces; Equivalence of Heat and Work; heat produced by Mechanical Action; heat consumed in producing work; Chemical Attractions; Attraction of Gravitation; amount of heat which would be produced by the stoppage of the Earth in its Orbit; amount produced by the falling of the Earth into the Sun; shifting of Atoms; heat consumed in Molecular Work; Specific Heat; Latent Heat; 'friability' of ice near its melting point; Rotten Ice and softened Wax
20. 334
Papers presented to the Royal Society by Professor Forbes in 1846; Capillary Hypothesis of glacier motion; hypothesis examined
Statement of theory; influence of Pressure on the Melting Point of Ice; difficulties of theory; Calculation of requisite Pressure; Actual pressure insufficient
Pressure and Tension; possible experiments; Ice may be moulded into Vases and Statuettes or coiled into Knots; this no proof of Viscosity; Actual Experiments; a sphere of ice moulded to a lens; a lens moulded to a cylinder; a lump of ice moulded to a cup; straight bars of ice bent; ice thus moulded incapable of being sensibly stretched; when Tension is substituted for Pressure, analogy with viscous body breaks down
Faraday's first experiments; Freezing together of pieces of ice at 32°; Freezing in Hot Water; Faraday's recent experiments; Regelation not due to Pressure nor to Capillary Attraction; it takes place in vacuo; fracture and regelation; no viscidity discovered
24.—Crystallization and Internal Liquefaction. 353
How crystals are 'nursed;' Snow-Crystals; Crystal Stars formed in Water; Arrangement of Atoms of Lake Ice; dissection of ice by a sunbeam; Liquid Flowers formed in ice; associated Vacuous Spots; curious sounds; their explanation; Cohesion of water when free from air; liquid snaps like a broken spring; Ebullition converted into Explosion; noise of crepitation; Water-cells in glacier ice; Vacuous Spots mistaken for Bubbles; not Flattened by Pressure; experiments; Cause of Regelation
Their character; Depth of Moulin on Grindelwald Glacier; Explanation the Grand Moulin of the Mer de Glace; Motion of moulins
26.—Dirt-Bands of the Mer de Glace.367
Their discovery by Professor Forbes; view of Bands from a point near the Flégère; Bands as seen from Les Charmoz; Skew Surface of glacier; aspect of Bands from the Cleft Station; Origin of bands; tendency to become straight; differences between observers
27.—Veined Structure of Glaciers.376
General appearance; Grooves upon the glacier; first observations; description by M. Guyot; observations of Professor Forbes; Structure and Stratification; subject examined; Marginal Structure; Transverse Structure; Longitudinal Structure; experimental illustrations; the Structure Complementary to the Crevasses; glaciers of the Oberland, Valais, and Savoy examined with reference to this question
28.—The Veined Structure and Differential Motion.395
Marginal Structure Oblique to sides; Drag towards the centre; difficulties of theory which ascribes the structure to Differential Sliding; it persists across the lines of maximum sliding
29.—The Ripple Theory of the Veined Structure. 398
Ripples in Water supposed to correspond to Glacier Structure; analysis of theory; observation of the MM. Weber; water dropping from an oar; stream cleft by an obstacle; Two Divergent lines of Ripple; Single Line produced by Lateral Obstacle; Direction of ripples compounded of River's motion and Wave motion; Structure and Ripples due to different causes; their positions also different
30.—The Veined Structure and Pressure. 404
Supposed case of pressed prism of glass; Experiments of Nature; Quartz-pebbles flattened and indented; Pressure would produce Lamination; Tangential Action
31.—The Veined Structure and the Liquefaction of Ice by Pressure.408
Influence of pressure on Melting and Boiling points; some substances swell, others shrink in melting; effects of pressure different on the two classes of bodies; Theoretic Anticipation by Mr. James Thomson; Melting point of Ice lowered by pressure; Internal Liquefaction of a prism of solid ice by pressure; Liquefaction in Layers; application to the Veined Structure
32.—White Ice-Seams of the Glacier du Géant. 413
Aspect of Seams; they sweep across the glacier concentric with Structure; Structure at the base of the Talèfre cascade; Crumples; Scaling off by pressure; Origin of seams of White Ice
33. 419
Glacier du Géant in a state of Longitudinal Compression; Measurements which prove that its hinder parts are advancing upon those in front; Shortening of its Undulations; Squeezing of white Ice-seams; development of Veined Structure
Summary 422