INDEX. 



A, Station on the Mer de Glace marked, 

 37, 125. 



Aar Glacier, 2 ; motion of the, 68, etc. ; ob- 

 servations on the motion of its surface and 

 bottom, 186 ; additional observations on 

 the velocity of, 206, 209, note ; different 

 reports do hot agree, 208 



Ablation of surface of glaciers, 157 ; its 

 amount ascertained, 170, 242. 



Agassiz, Professor, quoted, 2, 55, 68, 98, 208, 

 243, 250, note. 



Air bubbles in glaciers, 201 ; in lavas, 267. 



Aletsch, motion of glacier of, 15, 62. 



' Angle" on the Mer de Glace, ridges of ice 

 near, 205. 



Annual motion of different parts of the Mer 

 de Glace, 123, 222. See also the letters 

 indicating the various stations, and the 

 word Motion, 



Annual rings of glaciers, 25, 217. 



Ascensional movement of semifluid particles, 

 212. See Intumescence and Level. 



Auldjo, Mr., quoted, 83. 



Balmat, his observations on the velocity of 

 glaciers at different seasons, 126, etc., 224. 



Bos-Neves or snow-beds, 76. 



Bischoff, M., quoted, 98. 



Blackwell, Mr,, his observations at Cha- 

 mouni during winter, 271. 



Bois, Glacier des, its motion, 126, etc., 

 222, etc. 



Bossons, Glacier of, appearance of blocks 

 on the, 204 ; its motion, 126, etc., 222, 

 etc. ; rents in, frozen up, 162. 



Brenva, Glacier of La, revisited in 1846, 176, 

 etc. ; great increase since 1842, 177 ; its 

 cause, 178; records of its extent in 1846, 

 181 ; its remarkable veined structure, 19, 

 182, 256 ; traced to its mechanical cause, 

 182, etc. ; movement of the ice tested in 

 different directions, 184, 185. 



Bruising of ice produces the veined struc- 

 ture, and results from its fragility or im- 

 perfect plasticity, xvi, 47, 51, 53, 161, 162, 

 166, 201. 



C, Station on the Mer de Glace marked, its 

 motion, 36, 38, 123, 188, 221. 



Cadell, Mr. W. A., quoted, 82. 



Charpeutier. See De Cfiarpentier. 



Christie, Mr., quoted, 161, note ; his experi- 

 ment on the plasticity of ice on a small 

 scale, ib. ; the experiment varied, 167. 



Col du Tour, 227. 



Collapse of the parts of a glacier at the 

 close of summer, 27, 28, 1 54. 



Collin, M., on land-slips, quoted, 211. 



Collomb, M., quoted, 206. 



Cones, gravel, 241. 



Congelation of water in glaciers, xix, 23, 

 34, 47, 137, 163 ; congelation not neces- 

 sary to convert snow into pellucid ice, 

 200-202. 



I Conservative power of the ice, 196. 

 | Conversion of the Neve into ice, xx, 53, 163, 

 199 ; simultaneous and identical with the 

 formation of veined structure, 200 ; due 

 to pressure and increased by differential 

 motion, 200 ; commences near the sides 

 of the glacier, 201. 



Convex surface of glaciers, 49, 60, 152 ; of 

 land-slips, 211. 



" Corpora non agunt nisi soluta" an ex- 

 ploded doctrine, 201. 



Crease or wrinkle in semifluid bodies, 215, 

 216. 



Crevasses of glaciers perpendicular .to veined 

 structure on -he Glacier of the Rhone, 7, 

 81 ; their probable origin, 8 ; their vertica- 

 lity and transverse direction reconciled 

 with the facts of motion, 30, 54 ; crevasses 

 in lava streams, 45 ; crevasses in glaciers, 

 their distribution and extent, 143 ; their 

 size and importance often overrated, 

 143-5 ; their direction, 145 and note, 

 192 ; intersecting crevasses comparatively 

 uncommon, 146 ; length of, 147 ; do not 

 materially assist progression, 147 ; may 

 be due to general or to local distension, 

 151, 152; often renewed and sealed up 

 by collapse, 153 ; crevasses of the Mer de 

 Glace, 205 ; of glaciers in general, 240. 



D, Station marked at Montanvert, its mo- 

 tion, 36, 124, 189. 



Darwin, Mr., quoted, 92, 201, 267. 



De Charpentier's theory of glaciers, 15, 34, 

 248. 



Depression of level of a glacier, 27, 33 ; due 

 to several causes, 169 ; the effects sepa- 

 rated, 170 ; geometrical depression, 171 ; 

 correction of some results in volume of 

 " Travels," 172, note. 



De Saussure's theory of glaciers, xxi, 15 ; 



denned, 95, 249 ; modified, 101. 

 ! Detrusive force, 141. 



i Detrusion of semifluids, 216 ; in the metals, 

 218, 219. 



Dilatation theory, 15, 32, 249. 



