Chapter D

De Saussure's theory of glacier-motion, 156.
Dilatation theory, 155, 156.
Dirt-bands of Mer de Glace, observed by Prof. Forbes, 130;
description and explanation of, 131, 132.
Distillation, oceanic, 18; ordinary, 21.
Dôme du Goûté, broken crags of, 50.
Drifting of huts on ice, 59, 60.
Dr. William Hopkins's conclusions regarding the obliquity of the
lateral crevasses, 107.

E

Égralets, passage through the, 53.
Electric light, dark waves of, 14.
Equivalent points, comparison of velocities of, 75, 76, 107.
Erratic blocks, 147-150.
Evaporation, caused by the heat-rays of the sun, 13.
Expansion of water, 121, 155.
Experiments to show the heat-power of the dark rays, 14-19;
illustrative, 22, 23, 25, 20;
Dr. Franklin's experiment, 112.
Extract from Bordier's book, 157, 162.

F

Faraday's theory regarding regelation, 171;
special solidifying power exerted by substances upon their own
molecules, 172, 173;
opinion of Prof. James Thomson, 174, 175;
experiments illustrating the subject, 174;
quotation from Faraday, 175.
Fog, its formation in ball-rooms, 5.
Forces, of crystallization, 30;
of gravitation, 30;
of Nature, 31;
attractive and repulsive, 127.
Freezing mixture, 120, 168.

G

Glacier, the source of the Rhone, 7;
fed by mountain-snow, 7, 21;
melted by the sun's dark rays, 13;
terminal moraines of, 38;
questions regarding motions of, 54-58;
action of the ends of, 58;
motion at top and bottom of, 80, 81;
lateral compression of, 81, 82;
longitudinal compression of, 84, 85;
slow movement in winter of, 87;
motion of Grindelwald, 94;
motion of Great Aletsch, 94;
motion of Morteratsch, 95;
crevasses at the side of, 106;
action, 146, 147;
ice, 155;
veined or ribboned structure of, 178;
blue veins of, 170;
tables, 113, 114;
mills, 116-118;
theory of Scheuchzer regarding, 155;
ancient, 145-147;
impurities thrust out by, 144;
whiteness of a clean, 43, 170;
measurements by Hugi and Agassiz of, 59, 60;
epoch, 152-167.
Glacier des Bois, description of, 38-43.
---- des Bossons, 56;
mass of ice upon, 134.
---- of Aletsch, sand-cones of, 116.
---- des Périades, 51.
---- du Talèfre, boundary of, 53;
width of, 92;
chasms of the, 98.
---- de Léchaud, motion of, 80;
width of, 82;
compression of, 190.
---- du Géant, _névé_ of the, 49;
motion of, 79;
width of, 82;
cracks above the ice-falls of, 119;
honey-combing of, 115;
shortening of, 190.
---- Unteraar, movement of, 61;
appearance of Prof. Forbes on, 161;
measurements by Agassiz on, 162.
---- Görner, sand-cones of, 116;
description of, 140-144;
moraines of, 143;
advance and retreat of, 144;
objects of interest on, 144;
structure and bedding on, 181.
Grand Plateau, crevasse on, 57, 118.
Greenland's icy mountains, 21.
Growth of knowledge, 59.
Guesses in science, 74.

H

Harmony of life and its conditions, 125.
Heat, waves of, 12;
invisible, 14;
office of the invisible waves of, 36;
absorption of solar, 100;
demanded for the liquefaction of ice, 131;
latent, 153.
Hoar-frost, 5, 6;
not melted by light-waves, 13, 18.
Hôtel des Neuchâtelois, movements of, at Riffelberg, 141.