Furgge glacier; thunder and lightning; the Weissthor given up; excursion by Stalden to Saas; Herr Imseng; the Mattmark See and Hotel; ascent of a boulder; Snow-storm; cold quarters; the Monte Moro; the Allalein glacier; a noble vault; Structure and Dirt-bands; stormy weather; Avalanches at Saas; the Fée glacier; Frozen dust on the Mischabelhörner; Snow, Vapour, and Cloud; curious effect on the hearing; "a Terrible Hole;" singular group; a Song from 'The Robbers'
24. 168
Need of observations on Alpine Temperature; Balmat's intention; aid from the Royal Society; Difficulties at Chamouni in 1858; the Intendant memorialised; his response; the Séracs revisited; Crevasses and Crumples; bad weather; thermometers placed at the Jardin; Avalanches of the Talèfre; wondrous sky
25.—Second Ascent of Mont Blanc (1858).177
Shadows of the Aiguilles; Silver Trees at sunrise; M. Necker's letter; Birds as Sparks and Stars against the sky; crevasse bridged; ladder rejected; a hunt for a pont; crevasses crossed; Magnificent Sunset; illuminated clouds; Storm on the Grands Mulets; a Comet discovered; start by starlight; the Petit Plateau a reservoir for avalanches; Balmat's warning; the Grand Plateau at dawn; blue of the ice; Balmat in danger; Clouds upon the Calotte; the Summit; wind and snow-dust; Balmat frostbitten; halt on the Calotte; descent to Chamouni; good conduct of porters
26. 192
Hostility of Chief Guide; Procès Verbal; the British Association; application to the Sardinian authorities; President's Letter; Royal Society; Testimonial to Balmat
27.—Winter Expedition to the Mer de Glace, 1859. 195
First defeat and fresh attempt; Geneva to Chamouni; deep snow; Desolation; slow progress; a horse in the snow; a struggle; Chamouni on Christmas night; mountains hidden; Climb to the Montanvert; Snow on the Pines; débris of avalanches; Breaking of snow; Atmospheric Changes; the mountains concealed and revealed; colour of the snow; the Montanvert in Winter; footprints in the snow; wonderful frost figures; Crystal Curtain; the Mer de Glace in Winter; the first night; "a rose of dawn;" Crimson Banners of the Aiguilles; the stakes fixed; a Hurricane on the glacier; the second night; Wild Snow-storm; a man in a crevasse; calm; Magnificent Snow Crystals; Sound through the falling snow; swift descent; Source of the Arveiron; Crystal Cave; appearance of water; westward from the vault; Majestic Scene; Farewell
PART II.
What is Light?—notion of the ancients; requires Time to pass through Space; Römer, Bradley, Fizeau; Emission Theory supported by Newton, opposed by Huyghens; the Wave Theory established by Young and Fresnel; Theory explained; nature of Sound; of Music; of Pitch; nature of Light; of Colour; two sounds may produce silence; two rays of light may produce darkness; two rays of heat may produce cold; Length and Number of waves of light; Liquid Waves; Interference; Diffraction; Colours of Thin Plates; applications of the foregoing to cloud iridescences, luminous trees, twinkling of stars, the Spirit of the Brocken, &c.
2.—Radiant Heat. 239
The Sun emits a multitude of Non-luminous Rays; Rays of Heat differ from rays of Light as one colour differs from another; the same ray may produce the sensations of light and heat
3.—Qualities of Heat.241
Heat a kind of Motion; system of exchanges; Luminous and Obscure Heat; Absorption by Gases; gases may be transparent to light, but opaque to heat; Heat selected from luminous sources; the Atmosphere acts the part of a Ratchet-wheel; possible heat of a Distant Planet; causes of Cold in the upper strata of the Earth's Atmosphere
Application of principles; the Snow-line; its meaning; waters piled annually in a solid form on the summits of the hills; the Glaciers furnish the chief means of escape; superior and inferior snow-line
5. 249
Whiteness of snow; whiteness of ice; Round air-bubbles; melting and freezing; Conversion of snow into ice by Pressure
6.—Colour of Water and Ice.253
Waves of Ether not entangled; they are separated in the prism; they are differently absorbed; Colour due to this; Water and Ice blue; water and ice opaque to radiant heat; Long Waves shivered on the molecules; Experiment; Grotto of Capri; the Laugs of Iceland
Newton's idea; Goethe's Theory; Clausius and Brücke; Suspended Particles; singular effect on a painting explained by Goethe; Light separated without Absorption; Reflected and Transmitted light; blueness of milk and juices; the Sun through London smoke; Experiments; Blue of the Eye; Colours of Steam; the Lake of Geneva
Glacier loaded along its edges by the ruins of the mountains; Lateral Moraines; Medial Moraines; their number one less than the number of Tributaries; Moraines of the Mer de Glace; successive shrinkings; Glacier Tables explained; 'Dip' of stones upon the glacier enables us to draw the Meridian Line; type 'Table;' Sand Cones; moraines engulfed and disgorged; transparency of ice under the moraines
9.—Glacier Motion—Preliminary. 269
Névé and Glacier; First Measurements; Hugi and Agassiz; Escher's defeat on the Aletsch; Piles fixed across the Aar glacier by Agassiz in 1841; Professor Forbes invited by M. Agassiz; Forbes's first observations on the Mer de Glace in 1842; motion of Agassiz's piles measured by M. Wild; Centre of the glacier moves quickest; State of the Question
10.—Motion of the Mer de Glace.275
The Theodolite; mode of measurement; first line; Centre Point not the
