238 See Lyell's Travels in N. America, ch. 2 and 25.

239 See Manual of Geology, chap. 29 to 33, inclusive.

240 See ch. 26, infrà.

241 See ch. 27, infrà.

242 Ann. des Sci. Nat., Septembre, Novembre, et Décembre, 1829. Revue Française, No. 15, May, 1830. Bulletin de la Société Géol. de France, p. 864, May, 1847. The latest edition of M. de Beaumont's theory will be found in the 12th vol. of the Dictionnaire Universel d'Hist. Nat. 1852, art. "Systèmes des Montagues;" also the same printed separately.

243 Système de Mont. p. 762.

244 Ibid. pp. 761 and 773.

245 Phil. Mag. and Annals, No. 58. New Series, p. 242.

246 Système de Montagnes, 1852, p. 429.

247 Phil. Mag. and Annals, No. 58. New series, p. 243.

248 Système de Montagnes, 1852, p. 429.

249 For page, see Index, "Hopkins."

250 Art. Système de Montagnes, p. 775.

251 M. E de Beaumont in his later inquiries (Comptes rendus, Sept. 1850, and Systèmes des Montagnes) has come to the conclusion, that the principal mountain ranges, if prolonged, would intersect each other at certain angles, so as to produce a regular geometric arrangement, which he calls "a pentagonal network." This theory has been ably discussed and controverted by Mr. Hopkins, in his Anniversary Address as President of the Geol. Soc., Feb. 1853.

252 Darwin's Geology of South America, p. 248. London, 1846.

253 Système de Montagnes, p. 748.

254 See Lyell's Manual of Elementary Geology, ch. 5.

255 See the Author's Anniversary Address, Quart. Journ. Geol. Soc. 1850, vol. vi. p. 46, from which some of the above passages are extracted.

256 See Lyell's Manual of Elementary Geology.

257 Reports to Brit. Assoc. 1842, 1843, and Introd. to Brit. Foss. Mamm. p. 31. The conchological evidence respecting the British Miocene, Pliocene, and Pleistocene fossils, examined by Mr. Forbes, in the paper before cited, p. 88, note, bear out some of the most important conclusions of M. Deshayes, quoted by me in the first edition of the Principles, 1831, and the recent observations of Philippi in regard to the passage of species from one formation to another. I refer to these authorities more especially because this doctrine of a gradual transition has been opposed by some living naturalists of high distinction, among whom I may mention M.A. d'Orbigny and M. Agassiz. I have long been convinced that we must abandon many of the identifications formerly made of Eocene with recent shells; but some errors of this kind do not affect the general reasoning on the subject. See a discussion on this question, Quarterly Journ. of Geog. Soc., No. 5, p. 47 Feb. 1846.

258 Darwin's Journal, p. 163. 2d. ed. p. 139.

259 Journ. Roy. Geograph. Soc. vol. iii. p. 142.

260 Book iii. ch. 50.

261 Darwin's S. America, pp. 136, 139.

262 Miller, Phil. Trans. 1851, p. 155.

263 Phil. Trans. 1850, p. 354.

264 Hooker's Himalayan Journal, ined.

265 Ibid.

266 See Manual of Geology, Index, Rain-prints.

267 See Lyell on recent and fossil rains. Quart. Journ. Geol. Soc. 1851, vol. vii. p. 239.

268 Lyell's Second Visit to the United States, 1846, vol. ii. p. 25.

269 Encyc. Brit. art. Rivers.

270 Sir T. D. Lauder's Account of the Great Floods in Morayshire, August, 1829.

271 Quarterly Jour. of Sci. &c. No. xii. New Series, p. 331.

272 Culley, Proceed. Geol. Soc. 1829.

273 Silliman's Journal, vol. xv. No. 2, p. 216. Jan. 1829.

274 Silliman's Journal, vol. xxxiv. p. 115.

275 See Lyell's Second Visit to the U. S. vol. i. p. 69.

276 This block was measured by Capt. B. Hall, R. N.

277 Inundation of the Val de Bagnes, in 1818, Ed. Phil. Journ., vol. i. p. 187, from memoir of M. Escher.

278 Lib. viii. Epist. 17.

279 When at Tivoli, in 1829, I received this account from eye-witnesses of the event.

280 Illustr. of Hutt. Theory, § 3, p. 147.

281 Quadro Istorico dell' Etna, 1824.

282 The reader will find in my Travels in North America, vol. i. ch. 2, a colored geological map and section of the Niagara district, also a bird's-eye view of the Falls and adjacent country, colored geologically, of which the first idea was suggested by the excellent original sketch given by Mr. Bakewell. I have referred more fully to these and to Mr. Hall's Report on the Geology of New York, as well as to the earlier writings of Hennepin and Kalm in the same work, and have speculated on the origin of the escarpment over which the Falls may have been originally precipitated. Vol. i. p. 32, and vol. ii. p. 93.

283 Consid. sur les Blocs Errat. 1829.

284 Capt. Bayfield, Geol. Soc. Proceedings, vol. ii. p. 223.

285 M. Arago, Annuaire, &c. 1833; and Rev. J. Farquharson, Phil. Trans. 1835, p. 329.

286 Journ. of Roy. Geograph. Soc. vol. vi. p. 416.

287 See Système Glaciaire, by Agassiz, Guyot, and Desor, pp. 436, 437, 445. Mr. Agassiz, at p. 462, states that he published in the Deutsche Vierteljahrschrift for 1841, this result as to the central motion being greater than that of the sides, and was, therefore, the first to correct his own previous mistake.

288 J. Forbes. 8th Letter on Glaciers, Aug. 1844.

289 See Mr. Hopkins on Motion of Glaciers, Cambridge Phil. Trans. 1844, and Phil. Mag. 1845. Some of the late concessions of this author as to a certain plasticity in the mass, appear to me to make the difference between him and Professor Forbes little more than one of degree. (For the latest summary of Prof. Forbes' views, see Phil. Trans. 1846, pt. 2.)

290 This experiment is cited by Mr. Forbes, Phil. Trans. 1846, p. 206; and I have conversed with Mr. Christie on the subject.

291 Etudes sur les Glaciers, 1840.

292 See Manual of Geol. ch. xi.

293 Agassiz, Jam. Ed. New Phil. Journ. No. 54, p. 388.

294 Charpentier, Ann. des Mines, tom. viii.; see also Papers by MM. Venetz and Agassiz.

295 Voyage in 1822, p. 233.

296 Travels in Norway.

297 Darwin's Journal, p. 283.

298 Journ. of Roy. Geograph. Soc. vol. ix. p. 526.

299 Journ. of Roy. Geograph. Soc. vol. ix. p. 529.

300 Ibid. vol. viii. p. 221.

301 In my Travels in N. America, pp. 19, 23, &c., and Second Visit to the U. S., vol. i. ch. 2, also in my Manual of Geology, a more full account of the action of floating ice and coast-ice, and its bearing on geology, will be found.

302 Jam. Ed. New Phil. Journ. No. xlviii. p. 439.

303 Bulletin de la Soc. Géol. de France, 1847, tom. iv. pp. 1182, 1183.

304 Consult J. Prestwich, Water-bearing Strata around London. 1851. (Van Voorst)

305 Sabine, Journ. of Sci. No. xxxiii. p. 72. 1824.

306 Héricart de Thury, "Puits Forés," p. 49.

307 Prestwich, p. 69.

308 Bull. de la Soc. Géol. de France, tom. iii. p. 194.

309 Boué Résumé des Prog. de la Géol. en 1832, p. 184.

310 Seventh Rep. Brit. Ass. 1837, p. 66.

311 H. de Thury, p. 295.

312 Bull. de la Soc. Géol de France, tom. i. p. 93.

313 Bull. de la Soc. Géol. de France, tom. ii. p. 248.

314 See Glossary, "Tufa," "Travertin."

315 Dr. Grosse on the Baths of San Filippo, Ed. Phil. Journ. vol. ii p. 292.

316 Consolations in Travel, pp. 123-125.

317 Ibid. p. 127.

318 C. Prevost, Essai sur la Constitution Physique du Bassin de Vienne, p. 10.

319 Travels across the Andes, p. 240.

320 Annalen der Chem. 1847.

321 Daubeny on Volcanoes, p. 222.

322 Dr. Webster on the Hot Springs of Furnas, Ed. Phil. Journ. vol. vi. p. 306.

323 See a cut of the Icelandic geyser, chap. 32.

324 M. Robert, Bullétin de la Soc. Géol. de France, tom. vii. p. 11.

325 Barrow's Iceland, p. 209.

326 See Lyell's Manual of Elementary Geology; and Dr. Turner, Jam. Ed. New Phil. Journ. No. xxx. p. 246.

327 L. Horner, Geol. Trans, vol. ii. p. 94.

328 Ann. de l'Auvergne, tome i. p. 234.

329 Ann. Scient. de l'Auvergne, tome ii. June, 1829.

330 Edinb. New Phil. Journ. Oct. 1839.

331 See Lyell's Travels in N. America, vol. i p. 150.

332 Symes, Embassy to Ava, vol. ii. Geol. Trans. second series, vol. ii. part iii. p. 388.

333 Dr. Nugent, Geol. Trans. vol. i. p. 69.

334 Ibid. p. 67.

335 De la Beche, Ed. Phil. Journ. vol. ii. p. 107. Jan. 1820.

336 De la Beche, MS.

337 De la Beche, MS.

338 Trans. of Lit. and Hist. Soc. of Quebec, vol. i. p. 5, 1829.

339 Prony, see Cuvier, Disc. Prelim, p. 146.

340 See De Beaumont, Géologie Pratique, vol. i. p. 323, 1844.

341 Prony, cited by Cuvier, Discours Prélimin.

342 Brocchi, Conch. Foss. Subap. vol. i. p. 118.

343 Archiac, Histoire des Progrés de la Géol. 1848, vol. ii. p. 232.

344 Brocchi, Conch. Foss. Subap. vol. i. p. 39.

345 Ibid. vol. ii. p. 94.

346 Mém. d'Astruc, cited by Von Hoff, vol. i. p. 288.

347 Lib. ii. c. v.

348 Bouche, Chorographie et Hist. de Provence, vol. i. p. 23, cited by Von Hoft, vol. i. p. 290.

349 Hist. Phys. de la Mer.

350 Karamania, or a brief Description of the Coast of Asia Minor, &c. London, 1817.

351 Geog. Syst. of Herod, vol. ii. p. 107.

352 Euterpe, XI.

353 Journ. of Roy. Geograph. Soc. vol. ix. p. 432.

354 Quart. Journ. Geol. Soc. vol. v.; Memoirs, p. 20; and Lassaigue, Journ. Pharm. t. v. p. 468.

355 Quart. Journ. Geol. Soc. 1848, vol. iv. p. 342.

356 Flint's Geography, vol. i. p. 142. Lyell's Second Visit to the United States, vol. ii chaps. 28 to 34.

357 Geograph. Descrip. of Louisiana, by W. Darby, Philadelphia, 1816, p. 102.

358 Flint's Geography, vol. i. p. 152.

359 Travels in North America, vol. iii. p. 361.

360 Travels in North America, vol. iii. p. 362.

361 "The boats are fitted," says Captain Hall, "with what is called a snag-chamber;—a partition formed of stout planks, which is calked, and made so effectually water-tight that the foremost end of the vessel is cut off as entirely from the rest of the hold as if it belonged to another boat. If the steam-vessel happen to run against a snag, and that a hole is made in her bow, under the surface, this chamber merely fills with water."—Travels in North America, vol. iii. p. 363.

362 Darby's Louisiana, p. 33.

363 Featherstonhaugh, Geol. Report, Washington, 1835, p. 84.

364 Trees submerged in an upright position have been observed in other parts of N. America. Thus Captains Clark and Lewis found, about the year 1807, a forest of pines standing erect under water in the body of the Columbia river, which they supposed, from the appearance of the trees, to have been submerged only about twenty years. (Travels, &c. vol. ii. p. 241.) More lately (1835), the Rev. Mr. Parker observed on the same river (lat. 45° N., long. 121° W.) trees standing in their natural position in spots where the water was more than twenty feet deep. The tops of the trees had disappeared; but between high and low water-mark the trunks were only partially decayed; and the roots were seen through the clear water, spreading as they had grown in their native forest. (Tour beyond the Rocky Mountains, p. 132.) Some have inferred from these facts that a tract of land, more than twenty miles in length, must have subsided vertically; but Capt. Fremont, Dec. 1845 (Rep. of Explor. Exped. p. 195), satisfied himself that the submerged forests have been formed by immense land-slides from the mountains, which here closely shut in the river.

365 For an account of the "sunk country," shaken by the earthquake of 1811-12, see Lyell's Second Visit to the United States, ch. 33.

366 Darby's Louisiana, p. 103.

367 The calculations here given were communicated to the British Association, in a lecture which I delivered at Southampton in September, 1846. (See Athenæum Journal, Sept. 26, 1846, and Report of British Association, 1846, p. 117.) Dr. Riddell has since repeated his experiments on the quantity of sediment in the river at New Orleans without any material variation in the results.

Mr. Forshey, in a memoir on the Physics of the Mississippi, published in 1850, adopts Dr. Riddell's estimate for the quantity of mud, but takes 447,199 cubic feet per second as the average discharge of water for the year at Carrolton, nine miles above New Orleans, a result deduced from thirty years of observations. This being one-tenth more than I had assumed, would add a tenth to the sediment, and would diminish by one-eleventh the number of years required to accomplish the task above alluded to. "The cubic contents of sedimentary matter," says Forshey, "are equal to 4,083,333,333, and this sediment would annually cover twelve miles square one foot deep."

368 The Mississippi is continually shifting its course in the great alluvial plain, cutting frequently to the depth of 100, and even sometimes to the depth of 250 feet. As the old channels become afterwards filled up, or in a great degree obliterated, this excavation alone must have given a considerable depth to the basin, which receives the alluvial deposit, and subsidences like those accompanying the earthquake of New Madrid in 1811-12 may have given still more depth.

369 Account of the Ganges and Burrampooter rivers, by Major Rennell, Phil. Trans. 1781.

370 Trans. of the Asiatic Society, vol. vii. p. 14.

371 Cuvier referred the true crocodiles of the Ganges to a single species, C. biporcatus. But I learn from Dr. Falconer that there are three well-marked species, C. biporcatus, C. palustris, and C. bombifrons. C. bombifrons occurs in the northern branches of the Ganges, 1000 miles from Calcutta; C. biporcatus appears to be confined to the estuary; and C. palustris, to range from the estuary to the central parts of Bengal. The garial is found along with C. bombifrons in the north, and descends to the region of C. biporcatus in the estuary.

372 See below, ch. 22 and 29.

373 Second Visit to the United States, vol. ii. p. 145.

374 Asiatic Researches, vol. xvii. p. 466.

375 Lyell's Second Visit to the United States, vol. ii. chap. 34.

376 See Manual of Geology by the Author.

377 See p. 13.

378 Geog. of Herod, vol ii. p. 331.

379 Ibid. p. 328.

380 Romme, Vents et Courans, vol. ii. p. 2. Rev. F. Fallows, Quart. Journ. of Science, March, 1829.

381 The heights of these tides were given me by the late Captain Hewett, R. N.

382 On the authority of Admiral Sir F. Beaufort, R. N.

383 Consult the map of Currents by Capt. F. Beechy, R. N., Admiralty Manual, 1849, London.

384 Rennell on Currents, p. 58.

385 Rennell on the Channel current.

386 An. du Bureau des Long. 1836.

387 Second Parliamentary Report on Steam Communication with India, July, 1851.

388 Phil. Trans. 1830, p. 59.

389 See Capt. B. Hall, On Theory of Trade Winds, Fragments of Voy. second series, vol. i., and Appendix to Daniell's Meteorology.

390 Treatise on Astronomy, chap. 3.

391 Descrip. of Shetland Islands, p. 527, Edin. 1822, to which work I am indebted for the following representations of rocks in the Shetland Isles.

392 Dr. Hibbert, from MSS. of Rev. George Low, of Fetlar.