276 



INDEX. 



" Dirt- bands," discovery of, 21, 25, 39 ; 

 dirt-bands described, 245; their analo- 

 gues in mud-slides, 213. 



Discontinuity of glaciers, three orders of, 

 205. 



Dollfuss and Martins, MM., their observa- 

 tions on the glacier of the Aar, 186, 206. 



Ductility of ice not great, 161 ; its grada- 

 tions, 161, 162. See Fragility, Plasticity. 



Edinburgh Review, article on Glaciers in 



the, xxviii, 10. 

 Egralets, Les, 193. 

 Elie *de Beaumont, M., quoted, 48, 49, 



84, 87. 

 Erratics, their appearance on the surface of 



glaciers, 60, 202 ; often difficult to explain. 



203. 



Escher, M., quoted, 15. 

 Etna, lavas of Mount, 88. 

 Experiments on the flow of plastic bodies, 



77 ; on the plasticity of ice on the great 



scale, 103, etc. ; on the small scale, 161, 



note, 167. 

 Extrusion of stones from glaciers, 60, 202. 



Facts of glacier motion, 11, 35, 251, etc. 



Faraday, Mr., quoted, xiii, xxiii, 228 ; on 

 some properties of ice, 266. 



Firn, 244. 



Flames from Vesuvius, 44, note. 



Fluid motion with friction, 23, 31, 35, 78, 

 etc. 



Fragility of ice not inconsistent with the 

 theory of plasticity, 35, 47, 51, 53, 160 ; 

 diminished by impending fusion, 166, 

 225 ; it is succeeded by reattachment of 

 the surfaces, 161, 201. 



Freezing point of water, liable to some gra- 

 dation, 229. 



Friction of semifluids, 212. See Fluid. 



Frontal dip, 19, 24, 41, 46, 59, 70, 159, 204 ; 

 its analogue in lava streams, 90 ; in pitch, 

 93, 270 ; in mud-slides, 212, 217 ; frontal 

 dip illustrated in metal turnings, 219. 



Frontal resistance, 59, 71, 145, note, 204; 

 in mud -slides, 212, 217; in metals, 

 218. 



G,* Station on Mer de Glace marked, 144, 

 note. 



Gay Lussac, quoted, 201. 



Geant, Glacier du, its ice-fall, 199 ; wrinkles 

 on, 40, 199 ; difficulty of traversing, 199, 

 note. 



Glaciers, passim. In great glaciers the win- 

 ter's cold does not penetrate the entire 

 mass, 137 ; a glacier not a mass of frag- 

 ments, 141, 142. 



Glaciers, general account of, 233 ; names 

 for in different languages, 233 ; of the 

 Himalaya, 235; of Norway, 237; of 

 Spitzbergen, 238 ; of South America, 

 238 ; of the Alps, 237, 239 ; laws of mo- 

 tion recapitulated, 251-3. 



Glaciers of the second order, 244; their 

 veined structure, 21 ; their motion, 67, 



146. For individual glaciers, see their 



respective names. 



Gordon, Professor, quoted, 92, 141,215,269. 

 Gravitation theory, 248. 

 Grindelwald, lower Glacier of, 41. Frontal 



dip, and wrinkles upon, ibid. 

 Gruner, quoted, 95. 

 Guicharda, M., his observations on the 



Glacier of La Brenva, 179, 180. 



Hall, Captain, quoted, 83. 



Hammer, one lost and found on the glacier, 



196, note. 



Himalaya, glaciers of the, 235. 

 Hopkins, Mr., quoted, 62, 102, 103, 187. 

 Hugi, M., quoted, 248. 

 Huxley, Mr., quoted, xv, 228. 



Ice, on some properties of, near its melting 

 point, 228, 266 ; gradual fusion of, accom- 

 panied by softening, 35, 154, 166, note. 



Illustrations of the viscous theory of glacier 

 motion, 77, etc. 



Intumescence of lava, 47 ; cause of the, 91 ; 

 of glaciers, 156, 158 ; of mud-slides, 212. 



Knapsack, history of one lost and recovered 

 on the glacier, 193, etc. 



Land-slips, their analogies to glaciers, 211 ; 

 described by M. Collin, 211, etc. ; land- 

 slip at Lyme-Regis, 216. 



Lava streams, phenomena of, 44, etc. ; mo- 

 raines of, 48; their analogy to glaciers, 

 82 ; intumescence of, 47, 91 ; veined struc- 

 ture in, 46, 92, 267. 



Lava, velocity of, 85, 93. 



Letters on glaciers, first, 9 ; second, 13 : 

 third, 17; fourth, 26; fifth, 35; sixth, 

 43 ; seventh, 56 ; eighth, 61 ; ninth, 68 ; 

 eleventh, 169; twelfth, 176; thirteenth, 

 186 ; fourteenth, 205 ; fifteenth, 210 ; 

 sixteenth, 220. 



Level of glaciers. See Depression. 



Level recovered during winter, 28 ; at first 

 supposed to be due to congelation, 34 ; 

 afterwards, more correctly, to frontal 

 resistance acting on the plastic mass, 

 especially during winter, 60, 156, 158, 

 218, note, 259 ; changes of level in diffe- 

 rent years, 37, 158, 177. 



Lines of tearing-, 201. 



Longitudinal fissures exceptional, 147, 162. 



Lyme-Regis, land-slip at, 216 ; wrinkles 

 formed by, ibid. 



Martins, M., quoted, 99, 101, 209, 238. 

 Mer de Glace of Chain ouni, experiments on 



its motion, 11, 123, 188, 221, et passim ; 



change of level in different years, 37, 



158; ablation, 169, etc. ; subsidence, 170; 



relative motion of surface and bottom, 



172 ; old moraine of, 42. 

 Mer de Glace. See also Glacier des Bois, 



and Letters denoting the various stations. 

 Miage, Glacier of, 83; its velocity, 198; 



its moraines, 198. 



