FOOTNOTES:

[1] The Earth. Johnson’s Encyclopædia. See also statement of Murray in Smithsonian An. Rept., 1899, p. 312. Reprint from Brit. A. A. S., Dover meeting, 1899, and Scot. Geog. Mag., Vol. XV, 1899, p. 511.

[2] Its specific gravity as a whole is about 5.57, and the specific gravity of its outer portion is about 2.7.

[3] For an excellent study of the erosion, transportation, and sedimentation performed by the atmosphere, see Udden, Jour. of Geol., Vol. II, pp. 318–331. See also Pop. Sci. Mo., September, 1896.

[4] The Eruption of Krakatoa. Committee of the Royal Society, 1888.

[5] A brief account of the influence of the dust on sunsets is found in Davis’s Elementary Meteorology, pp. 85 and 119.

[6] Science, New Ser., Vol. IV, p. 816, 1896.

[7] Von Richtofen. “China.”

[8] Sketcherley and Kingsmill. Quar. Jour. Geol. Soc., Vol. LI, 1895, pp. 238–254.

[9] Chamberlin. Jour. of Geol., Vol. V, p. 795.

[10] A thoroughgoing study of the Formation of Sand Dunes (by V. Cornish) is to be found in the Geog. Jour., Vol. IX, 1897, pp. 278–309.

[11] Blanford. Geology of India, 2d ed., p. 455 et seq.

[12] Cornish, loc. cit.

[13] Cornish, loc. cit., p. 294.

[14] Diller states (17th Ann. Rept., U. S. Geol. Surv., Pt. I, p. 450) that on the coast of Oregon the slope of dunes is sometimes 40°.

[15] From folio preface, U. S. Geol. Surv.

[16] Credner. Elemente der Geologie, 6th ed., p. 271.

[17] Merrill. Rocks, Rock Weathering, and Soils, p. 295.

[18] Cowles. The Ecological Relations of the Vegetation of the Sand Dunes of Lake Michigan. Botanical Gazette, Vol. XXVII, 1899. An excellent study of the relations of sand dunes and vegetation.

[19] For example, in the Big Horn Mountains of Wyoming.

[20] It should be noted that it is the change of temperature of the rock surface, not the change of temperature of the air above it, which is to be considered. Many data concerning temperature changes are to be found in Bartholomew’s Atlas of Meteorology.

[21] Buckley. Wisconsin Survey, Bull. IV, 1899, pp. 81–3.

[22] Livingstone has reported that the temperature of rock surfaces in Africa sometimes reaches 137° Fahr. during the day, and cools sufficiently at night to split off blocks of 200 lbs. weight.

[23] Buckley. Surv. of Wis., Bull. IV, pp. 19, 20.

[24] For an excellent discussion of erosion in dry regions see Walther’s Die Denudation in der Wüste.

[25] On the assumption that condensation takes place at an average elevation of 3000 feet, it has been estimated that the force necessary to evaporate and diffuse the moisture which falls as rain and snow would be equivalent to 300,000,000,000 horse-power constantly in operation. (Strachey, Lectures on Geography, p. 145.)

[26] McGee. Bull. Geol. Soc. Am., Vol. VIII, pp. 87–112.

[27] For a discussion of convex and concave erosion slopes see Bain, Geol. Surv. of Ia., Vol. VI, p. 449.

[28] Great rivers, like the Mississippi, cut their channels somewhat below sea-level, but probably not by an amount exceeding the depth of the stream itself (see p. 79).

[29] Davis. Jour. of Geol., Vol. X, p. 87.

[30] Ibid., p. 77 et seq.

[31] In regions where canyons are common, the term is often applied to all valleys.

[32] Humphreys and Abbot. Physics and Hydraulics of the Mississippi River.

[33] From Russell’s Rivers of North America, p. 78.

[34] Alkaline carbonates considered as sodium carbonates.

[35] Carbonic acid by difference.

[36] Babb. Science, Vol. XXI, p. 343. 1893.

[37] Quoted by Mason. Water-supply, p. 204.

[38] Sot. Geog. Mag., Vol. III, p. 76. 1887.

[39] Acids and bases combined according to the principles indicated by Bunsen.

[40] Chemical Geology, Vol. I, pp. 76, 77, English ed., 1854.

[41] Allgemeine und chemische Geologie, Vol. I, pp. 456, 457. 1879.

[42] Russell. Rivers of North America, p. 79.

[43] For disastrous floods of the lower Mississippi, see Johnson, Bull. Geol. Soc. Am., Vol. II, pp. 20–25. For effect of precipitation and forests on floods, see Russell’s Meteorology, pp. 198–217, and Vermeule, Report on Water Supply, Geol. Surv. of N. J.

[44] An excellent discussion of this subject is given by Gilbert in The Henry Mountains, pp. 99 et seq., and more briefly in the Am. Jour. Sci., Vol. XII, p. 85 et seq. 1876.

[45] Jour. of Geol., Vol. IV, p. 718. An excellent summary of the principles of Rock Weathering.

[46] Russell. Rivers of North America, p. 17.

[47] W. G. Thompson. Nature, Vol. I, p. 555, 1870. The Matapediac River, N. B. Cited by Russell in Rivers of North America, p. 25.

[48] Dutton. Tertiary History of the Grand Canyon District, Mono. II, U. S. Geological Survey.

[49] The terms rapids, falls, and cataracts are rather loosely used. Many moderate rapids are incorrectly called falls. The “Falls of the Ohio” is an example. The term cataract is often applied to very steep rapids or falls.

[50] Gilbert, article on Niagara Falls, in Physiography of the United States.

[51] Gilbert. Am. Jour. Sci., Vol. XII. p. 99, 1876.

[52] For a brief account of this fall see Gilbert in Physiography of the United States.

[53] Gilbert. Science, Vol. VIII, p. 205, 1886.

[54] See Campbell, Jour. Geol., Vol. IV, pp. 567, 657.

[55] Russell. Rivers of North America, p. 280. The influence of joints on drainage is further discussed by Hobbs, Jour. Geol., Vol. IX, p. 469.

[56] See Willis. The Northern Appalachians, in Physiography of the United States.

[57] This process of adjustment has been well described by Davis in The Rivers and Valleys of Pennsylvania, Natl. Geog. Mag., Vol. I, p. 211 et seq.

[58] This sort of adjustment may be called topographic adjustment. A tributary is in topographic adjustment when its gradient is harmonious with that of its main.

[59] Davis. The Seine, the Meuse and the Moselle. Nat’l Geog. Mag., Vol. VII, pp. 181–202, and 228–238. An article which throws much light on the behavior of rivers.

[60] Another view has been advocated by Tarr, Am. Geol. Vol. XXI, pp. 351–370.

[61] Campbell. Bull. Geol. Soc. of Am., Vol. XIV, p. 277.

[62] Willis. Physiography of the United States. The Northern Appalachians.

[62a] Willis. Physiography of the United States. The Northern Appalachians.

[63] For excellent accounts of the rivers of the Appalachian Mountains see Davis, Rivers of Northern New Jersey, Nat’l Geog. Mag., Vol. II, pp. 81–110; and Rivers of Pennsylvania, op. cit., pp. 183–253; Willis, The Northern Appalachians, Physiography of the United States, pp. 169–202; Hayes, the Southern Appalachians, op. cit., pp. 305–336; Hayes and Campbell, The Geomorphology of the Southern Appalachians, Nat’l Geog. Mag., Vol. VI, pp. 63–126, and Hayes, Physiography of the Chattanooga District, 19th Ann. Rep. U. S. Geol. Surv., Pt. II, pp. 1–58.

[64] This is the case at Davis and Lone Star. Capt Howell, Miss. Riv. Commission.

[65] Russell. Rivers of North America, p. 279.

[66] Russell. Rivers of North America, p. 279.

[67] Hayes. Physiography of the Chattanooga District, 19th Ann. Rep., U. S. Geol. Surv., Pt. II, pp. 9–58. See, also, Hayes and Campbell, Geomorphology of the Southern Appalachians, Nat’l Geog. Mag., Vol. VI, pp. 63–126.

[68] Figs. 165–168 are based on reports of Hayes, and Hayes and Campbell, already referred to. Drawn by E. S. Bastin.

[69] A question might be raised in this case as to what should be called the source. A spring issues from beneath the surface and flows away in a stream. The stream is said to begin where the water appears at the surface, though in some cases the water of the spring was a subsurface stream before it reached the surface. Water escaping from beneath a glacier as a stream may likewise be considered a spring at the point of its issue.

[70] Davis. Science, Vol. X, p. 142, 1887.

[71] L. C. Johnson. Bull. Geol. Soc. Am., Vol. II, pp. 20–25, 1891.

[72] Jefferson. Nat’l Geog. Mag., Vol. XIII, pp. 373–84.

[73] According to map published by the Mississippi River Commission in 1887.

[74] Russell. Rivers of North America, p. 114.

[75] Gilbert. Am. Jour. Sci., Vol. XXVII, 1884, pp. 427–34.

[76] Cooley. Rept. U. S. Engineers for 1879–80, Pt. II, pp. 1060 and 1071.

[77] Gerber. Cited by Todd. Bull. 158, U. S. Geol. Surv., pp. 150, 151.

[78] Chamberlin. Jour. of Geol., Vol. X, pp. 747–754.

[79] For an excellent discussion of deltas, see Gilbert, Fifth Ann. Rept. U. S. Geol. Surv., pp 104–8. Also Lake Bonneville, Monograph I, U. S. Geol. Surv. (same article).

[80] Davis. Physical Geography, p. 294.

[81] Humphreys and Abbot. Physics and Hydraulics of the Mississippi River.

[82] Corthell. Nat’l Geog. Mag., Vol. VIII, p. 351, 1897.

[83] Russell. Rivers of North America, p. 132.

[84] Prestwich. Chemical and Physical Geology, Vol. I, p. 85.

[85] Geike. Text-book of Geology, 3d ed., p. 402.

[86] Medlicott and Blanford, Geology of India. Chap. XVII; Medlicott, Records of the Geological Survey of India, 1881; Oldham, Geology of India, 2d ed., Chap. XVII; and Ferguson, Q. J. G. S., Vol. XIX, pp. 321–54. The extent of this and other deltas is variously stated, probably because it is difficult to determine the exact position of its head and borders.

[87] Dana. Manual of Geology, 4th ed., p. 198.

[88] Salisbury and Kümmel. Lake Passaic. Ann. Rept. of the State Geologist of New Jersey, 1893, and Jour. of Geol., Vol. III. p. 533.

[89] Gilbert. Lake Bonneville, Mono. I, U. S. Geol. Surv.

[90] For discussions of terraces see Gilbert’s Henry Mountains, p. 126; Davis’ River Terraces in New England, Bull. of the Mus. of Comp. Zool., Geol. Series, Vol. V, pp. 282–346; and Dodge, Proc. Boston Soc. of Nat. Hist., Vol. XXVI, pp. 257–73.

[91] Davis, Bull. Mus. Comp. Zool., Geol. Ser., Vol. V.

[92] This point has recently been emphasized by Davis, loc. cit., pp. 282–346.

[93] Murray. Scot. Geog. Mag., Vol. III, p. 70, 1887.

[94] Hoskins. 16th Ann. Rept., U. S. Geol. Surv., p. 853.

[95] Van Hise. Principles of North American Pre-Cambrian Geology, 16th Ann. Rept., U. S. Geol. Surv.

[96] For a full discussion of this subject see King, 19th Ann. Rept., U. S. Geol. Surv., Pt. II, and Slichter, Water Supply and Irrigation, Paper No. 67, U. S. Geol. Surv.

[97] For tables see Buckley, Building and Ornamental Stones, Bull. IV, Wis. Surv., and Merrill, Stones for Building and Decoration, and various Survey Reports.

[98] It is probable that the porosity decreases in more than an arithmetic ratio, both because the deeper rocks are not of porous kinds, and because of the pressure which tends to close openings.

[99] Slichter (op. cit., p. 15) estimates that the ground-water is sufficient in amount to cover the earth’s surface to a depth of 3000 to 3500 feet. Earlier estimates gave still higher figures (see Delesse, Bull. Soc. Geol., France, Second Series, Vol. XIX, 1861–62, p. 64).

[100] Geikie. Text-book of Geology, 3d ed., p. 367.

[101] Ibid., p. 378.

[102] Prestwich, Q. J. Geol. Soc., Vol. XXVIII, p. lxvii.

[103] Reade. Liverpool Geol. Soc., 1876 and 1884.

[104] This is not true in the case of minerals, such as lime carbonate, dissolved under the influence of gases in solution in the water.

[105] Weed. The Formation of Hot Springs Deposits. Excursion to the Rocky Mountains. Compte Rendu. Fifth Session of the International Geological Congress, p. 360, and Ninth Ann. Rept. U. S. Geol. Surv., pp. 613–76. Also B. M. Davis, Science, Vol. VI, pp. 145–57, 1897.

[106] For a racy and interesting account of caverns see Shaler’s Aspects of the Earth.

[107] Russell has emphasized this point in 20th Ann. U. S. Geol. Surv., Pt. II, pp. 193–202, and Cross, 21st Ann. U. S. Geol. Surv., Part II, pp. 129–150.

[108] Gooch and Whitfield. Bull. 47, U. S. Geol. Surv.

[109] Copied from Russell, Mono., XI. U. S. Geol. Surv., p. 176.

[110] Correction for specific gravity only approximate, as specific gravity was not given in original analyses.

[111] As carbonates.

[112] As carbonate.

[113] As oxide.

[114] As carbonate.

[115] As sodium chloride.

[116] As fluoride of calcium.

[117] Oxygen added to SiO2 to form SiO3 of Na2SiO3.

[118] Liters of gas thrown off per liter of water.

[119] Weed. Ninth Ann. Rept. U. S. Geol. Surv., pp. 613–76, and Am. Jour. Sci., Vol. XXXVII, 1889, pp. 351–59.

[120] Geikie. Geological Sketches, pp. 206–38. Hayden. Amer. Jour. Sci., Vol. III, 1872, pp. 105–15 and 161–76.

[121] Chamberlin. Geol. of Wis., Vol. I, pp. 689–97, and Fifth Ann. Rept., U. S. Geol. Surv., pp. 131–73. The former a brief, and the latter an elaborate, exposition of the principles involved.

[122] Russell. Nat’l Geog. Mag., Vol. III, pp. 127 and 181.

[123] For an account of experiments illustrating the mobility of ice see Aitkin, Am. Jour. Sci., Vols. V, p. 303, and XXXIV, p. 149, and Nature, Vol. XXXIX, p. 203.

[124] Jour. of Geol., Vol. III, p. 888.

[125] The following list includes many of the more available articles and treatises on existing glaciers; others are referred to in the following pages.

Alaskan glaciers: Reid, (1) Nat. Geog. Mag., Vol. IV, pp. 19–55; (2) Sixteenth Ann. Rept., U. S. Geol. Surv., Part I, pp. 421–461. Russell, (1) Nat. Geog. Mag., Vol. III, pp. 176–188; (2) Jour. of Geol., Vol. I, pp. 219–245.

Glaciers in the United States: Russell, (1) Fifth Ann. Rept., U. S. Geol. Surv., pp. 309–355; (2) Eighteenth Ann. Rept., U. S. Geol. Surv., Part II, pp. 379–409; (3) Glaciers of North America.

Greenland glaciers: Chamberlin, Jour. of Geol., Vol. II, pp. 768–788; Vol. III, pp. 61–69, 198–218, 469–480, 565–582, 668–681, and 833–843; Vol. IV, pp. 582–592. Salisbury, Jour. of Geol., Vol. III, pp. 875–902, and Vol. IV, pp. 769–810.

Glaciers in general: Shaler and Davis, Illustrations of the Earth’s Surface; Forbes, Norway and its Glaciers, and Theory of Glaciers; Heim, Handbuch der Gletscherkunde.

[126] Reid. Natl. Geog. Mag., Vol. IV, p. 44.

[127] Rink’s Greenland.

[128] Reid. Variations of Glaciers. Jour. of Geol., Vols. III, p. 278; V, p. 378; VI, p. 473; VII, p. 217; VIII, p. 154; IX, p. 250, and X, p. 313.

[129] For example, in the Middle Blase Dale glacier, Island of Disco, Jour. of Geol., Vol. II, p. 784, and in the Bowdoin glacier ([Fig. 242]).

[130] Centimeter-gramme-second system. The rate of conductivity has not been very accurately determined.

[131] Russell. Jour. of Geol., Vol. III, p. 823.

[132] Geikie. The Great Ice Age, 3d ed., p. 529.

[133] Carried out by C. E. Peet and E. C. Perisho under the direction of one of the authors.

[134] Ueber die Plasticität der Eiskrystalle. Neues Jahrbuch für Mineralogie, etc., 1895, Bd. II, p. 211.

[135] On the Plasticity of Glaciers and other Ice. Proc. Roy. Soc., Vol. XLIV, 1888, pp. 331–67 (with D. A. Kidd); Vol. XLVIII, 1890, pp. 259, 260; Vol. XLIX, 1891, pp. 323–43.

[136] Grönland-Expedition der Gesellschaft für Erdkunde zu Berlin, 1891–93, Bd. I, p. 491 et seq.

[137] References on glacier structure and motion.—L. Agassiz, Études sur les Glaciers, Neuchâtel, 1840. Rendu, Théorie des Glaciers de la Savoie, Soc. Roy. Acad., Savoie, Mém. 1840 (in English, ed. by Geo. Forbes, London, 1874). J. de Charpentier, Essai sur les Glaciers et le terrain erratique du Basin du Rhone, Lausanne, 1841. F. J. Hugi, Ueber das Wesen der Gletscher und Wintereise in dem Eismeer, Stuttgart, 1842. R. Mallet, The Mechanism of Glaciers, Jour. Geol. Soc. Dublin, Vol. I, p. 317; On the Plasticity of Glacier Ice, Jour. Geol. Soc. Dublin, 1845, Vol. III, p. 122; On the Brittleness and Non-plasticity of Glacier Ice, Phil. Mag., XXVI, p. 586. James Thompson, On the Plasticity of Ice as Manifested in Glaciers, Roy. Soc. Proc., Vol. 8, 1857, pp. 455–58. J. Tyndall and T. H. Huxley, On the Structure and Motion of Glaciers, Phil. Trans., 1857, Vol. CXLVII, p. 327. J. D. Forbes, Occasional Papers on the Theory of Glaciers, Edinburgh, 1859. W. Hopkins, On the Theory of the Motion of Glaciers, Phil. Trans., 1862, p. 677; Phil. Mag., 1863, Vol. XXV, p. 224. J. Tyndall, Forms of Water, New York, 1872; The Glaciers of the Alps, London, 1861. James Croll, On the Physical Cause of the Motion of Glaciers, Phil. Mag., 1869, Vol. 38, pp. 201–6. A. Heim, On Glaciers, Phil. Mag., 1871, Vol. 41, pp. 485–508; Handbuch der Gletscherkunde, 1885. H. Moseley, On the Cause of the Descent of Glaciers, Br. Assoc. Rept., 1860, Pt. 2, p. 48; also Phil. Mag., 1869, Vol. 37, pp. 229, 363; Vol. 39, p. 241; Vol. 42, p. 138; Vol. 43, p. 38. Ch. Grad, La Constitution et le movement des Glaciers, Revue Sci., 1872. H. J. Rink, Danish Greenland, 1877. R. M. Deeley, A Theory of Glacial Motion, Phil. Mag., 1888, Vol. 25, pp. 136–64. J. C. McConnel, On the Plasticity of an Ice Crystal, Proc. Roy. Soc. London, Vol. 48, 1890, pp. 256–60; ibid., Vol. 49, 1891, pp. 323–43. O. Mügge, Über die Plasticität der Eiskrystalle, Nachr. k. Ges. d. Wiss., Göttingen, 1895, pp. 1–4. R. M. Deeley and George Fletcher, The Structure of Glacier Ice and its Bearings on Glacier Motion, Geol. Mag. (London), Decade 4, Vol. 2, 1895, pp. 152–62. T. C. Chamberlin, Presidential address before the Geol. Soc. Am., Bull. Geol. Soc. Am., Vol. VI, February 1895, pp. 199–220. Reid, Mechanics of Glaciers, Jour. Geol., Vol. IV, 1896, p. 912. Erich von Drygalski, Grönland-Expedition der Gesellschaft für Erdkunde zu Berlin, 1891–93, Vol. I, 1897.

[138] Much information on these and other points is to be found in the following books: Wild’s Thalassa; Thompson’s Depths of the Sea; Barker’s Deep Sea Soundings, and Maury’s Physical Geography; Agassiz’ The Three Cruises of the Blake, and the Challenger Reports give much more detailed information concerning these and other matters.

[139] Dittmar, Challenger Reports, Physics and Chemistry, Vol. I, p. 204.

[140] For a discussion of the way in which this gas is held in solution, see Tolman, Jour. of Geol., Vol. VII, pp. 598–618.

[141] Murray, Scot. Geogr. Mag., Vol. IV, p. 39.

[142] Murray, Scot. Geogr. Mag., Vol. III, p. 76.

[143] Ibid., p. 70.

[144] Limited areas of the ocean bottom are actually concave upward; that is, they are basins in the more commonly accepted sense of the term (see [Chapter IX]).

[145] J. Geikie. Earth Sculpture, p. 329.

[146] Murray. Scottish Geographical Magazine, Vol. XV, p. 507.

[147] Lindenkohl. Science, Vol. X, 1899, p. 807.

[148] This does not hold for tropical latitudes.

[149] National Geographic Magazine, Vol. XI, pp. 377–392.

[150] For causes of ocean-currents, see Croll’s Climate and Time; Proc. Roy. Soc., 1869–73, and Jour. Roy. Geog. Soc., 1871–77.

[151] In the following pages concerning the waves and their work Gilbert’s classic discussion of shore features, in the Fifth Annual Report of the U. S. Geol. Survey, pp. 80–100, is freely drawn on. Another incisive discussion of certain shore phenomena is that of Fenneman, Jour. of Geol., Vol. X, pp. 1–32.

[152] Dana. Manual of Geology, 4th ed., p. 213.

[153] Delesse. Lithologie des Mers de France. Cited by Geikie, Text-book of Geology, 3d ed., p. 438.

[154] Sir G. Airy. Encyclopedia Metropolitana, Art. Waves. Cited by Geikie, loc. cit., p. 438.

[155] Stevenson. Treatise on Harbors.

[156] Willis. Jour. of Geol., Vol. I, p. 481.

[157] Stevenson. Trans. Roy. Soc. Edin., Vol. XVI, p. 25. Treatise on Harbors, p. 42. Quoted by Geikie, Text-book of Geology, p. 437.

[158] Geikie. Text-book of Geology, 3d ed., p. 437.

[159] Brit. Assoc. Rept., 1850, p. 26.

[160] Davis. Physical Geography, p. 354.

[161] Dana. Manual of Geology, 4th ed., p. 219.

[162] Shaler. Sea and Land, p. 29.

[163] Gulliver, Shore Line Topography: Proc. Am. Acad. Arts and Sci., Vol. XXXIV, 1899, pp. 151–258. A valuable study of shore-line topography.

[164] Willis. Jour. of Geol., Vol. I, p. 481.

[165] See Gilbert. Topographic Features of Lake Shores, 5th Ann. Rept. U. S. Geol. Surv.

[166] Shaler, Sea Coast Swamps of the U. S., 6th Ann. Rept. U. S. Geol. Surv.; and Merrill, Pop. Sci. Mo., Oct., 1890.

[167] Willis. Bull. Geol. Soc. Amer., Vol. IX, p. 113, and Tacoma, Wash., Folio, U. S. Geol. Surv.

[168] Agassiz. Three Cruises of the Blake, Vol. I, p. 259. Agassiz would ascribe the Blake plateau itself to the Gulf Stream, p. 138. See also Am. Jour. Sci., Vol XXXV, 1888, p. 498.

[169] Reade. Phil. Mag., Vol. XXV (1888), p. 342.

[170] Murray. Challenger Report, Deep Sea Deposits, pp. 184, 185.

[171] Murray, loc. cit., pp. 187, 188.

[172] Ibid.

[173] Stevenson. Harbors, 2d ed., p. 15.

[174] Usiglio. Encyclopædia Britannica. Article on Salt.

[175] Willis. Jour. of Geol., Vol. I, p. 500, where the evidences for deposition are fully set forth.

[176] Murray, loc. cit.

[177] Ibid., p. 186.

[178] Murray, loc. cit., p. 295.

[179] Challenger Report, Deep Sea Deposits, p. 327.

[180] Young’s Astronomy, p. 472.

[181] Murray. Scottish Geog. Mag., Vol. XV, p. 511. An excellent summary of deep-sea deposits.

[182] Murray, Challenger Report on Deep Sea Deposits, p. 337 et seq., and Buchanan, Proc. Roy. Soc. Edin., Vol. XVIII, 1892, pp. 17–39.

[183] Challenger Report on Deep Sea Deposits, pp. 385–391. See also Jour. of Geol., Vol. II, pp. 167–172.

[184] Forel, Compte Rendu, 1875, 1876, 1878, 1879, and p. Du Bois, 1891. Also Forel’s Lac Leman.

[185] C. A. Davis, Journ. of Geol., Vol. VIII, pp. 485–97, and 498–503, and Vol. IX, pp. 491–506.

[186] Russell, Lake Lahontan, Mono. XI, U. S. Geol. Surv., Chap. V; also Third Ann. Rept., pp. 211–221. Gilbert, Lake Bonneville, Mono. I, U. S. Geol. Surv., p. 167.

[187] Stapff, Zeit. deut. geol. Gesell., Vol. XVIII, pp. 86–173.

[188] Upham, Lake Agassiz, Mono. XXV, U. S. Geol. Surv.; Salisbury and Kümmel, Lake Passaic, Rept. of the State Geologist of N. J., 1893, and Jour. of Geol., Vol. III, pp. 533–560; Gilbert, Lake Bonneville, Mono. I, U. S. Geol. Surv.; Russell, Lake Lahontan, Mono. XI, U. S. Geol. Surv.; and Mono Lake, Eighth Ann. Rept., U. S. Geol. Surv., Pt. I.

[189] Gilbert, Lake Bonneville, Mono. I, U. S. Geol. Surv., p. 71, and Topographic Features of Lake Shores, Fifth Ann. Rept. U. S. Geol. Surv., p. 109.

[190] Buckley. Wis. Acad. of Sci., Vol. XIII, Pt. I, 1900. A study of ice ramparts formed about the shores of Lake Mendota, Wis., in 1898–99.

[191] Copied from Russell’s Lake Lahontan, Mono. XI, U. S. Geol. Surv.

[192] Less .04254 carbonic acid added to amount found. Average of two analyses.

[193] Average from four analyses.

[194] Average of two analyses.

[195] As sesquicarbonates.

[196] As chloride.

[197] As peroxide.

[198] Carbonic acid by difference.

[199] Analyses of Rocks, Bull. 168, U. S. Geol. Surv., 1900, p. 15.

[200] Quantitative Classification of Igneous Rocks, by Whitman Cross, Joseph p. Iddings, Louis V. Pirsson, and Henry S. Washington. 1903.

[201] Van Hise. 16th Ann. U. S. Geol. Surv., Pt. I, pp. 589–94.

[202] The application of these principles we owe chiefly to Van Hise: Metamorphism of Rocks and Rock Flowage, Bull. Geol. Soc. Am., Vol. 9, pp. 269–328.

[203] Cross, Iddings, Pirsson, and Washington. Quantitative Classification of Igneous Rocks.

[204] The initials f.n. (field names) are introduced to show that the term is used in the broad field sense proposed.

[205] Added by the authors of this work.

[206] The following definitions are given, as nearly as practicable, in accordance with present common usage, which is, however, more or less varying and inconsistent.

[207] A comprehensive discussion of the “Genesis of Ore Deposits” may be found in Vols. XXIII and XXIV of the Trans. of the Am. Inst. of Min. Eng. (also printed with additions in book form by the Institute, 1902), in which Posepny, Emmons, Van Hise, LeConte, Blake, Becker, Ricard, Raymond, Lindgren, Weed, Vogt, Winslow, Winchell (H. V.), Church, Cazin, Adams, Keyes, Bain, Collins, Beck, and DeLaunay participated. Various phases of the leading modern views are set forth.

[208] Chamberlin. Geol. of Wis., Vol. IV, p. 599 et seq., 1882.

[209] Penrose. Jour. of Geol., Vol. XI, pp. 135–155, 1903.

[210] Van Hise, Mono. XIX, U. S. Geol. Surv., pp. 268–295, 1892.

[211] Gilbert. Bull. Geol. Soc. Am., Vol. X, pp. 135–140, 1898.

[212] Branner. Jour. of Geol., Vol. VIII, pp. 481–484, 1900.

[213] Iddings. Jour. of Geol., Vol. VI, pp. 704–710.

[214] Daubrée. Géologie d’Expérimentale, pp. 306–372.

[215] Crosby. American Geologist, Vol. XII, 1893, pp. 368–375.

[216] Becker. Bull. U. S. Geol. Surv., Vol. X, pp. 41–75.

[217] Van Hise. Principles of North American Pre-Cambrian Geology. 16th Ann. Rept. U. S. Geol. Surv., Pt. I, pp. 668–672.

[218] Diller. Bull. Geol. Soc. Am., Vol. I, pp. 441–442. Ibid. Hay, Vol. III, pp. 50–55; and Newsom, ibid. Vol. XIV, pp. 227–268.

[219] Willis. Bull. Geol. Soc. of Am., Vol. XIII, pp. 331–336.

[220] McConnell. Canada Geol. and Nat. Hist. Surv., 1886, Pt. II.

[221] Geikie. Text-book of Geology.

[222] Becker. Geology of the Comstock Lode, Mono. III, U. S. Geol. Surv., Chapter IV.

[223] Reference, Van Hise. Sixteenth Ann. Rept. U. S. Geol. Surv., Pt. I, pp. 672–678.

[224] Davison. Jour. of Geol., Vol. VIII, p. 301.

[225] Nature, October 24, 1895.

[226] Milne. The Geog. Jour., Vol. XXI, p. 1. See also Seismology, a more technical work than the same author’s Earthquakes.

[227] Darwin. Journal of Researches, 1845, p. 303.

[228] Oldham. Quar. Jour. Geol. Soc., Vol. XXVIII, p. 257.

[229] Geikie. Text-book of Geology, 4th ed., p. 372.

[230] Kotô. Jour. Coll. Sci., Japan, Vol. V, Pt. IV (1893), pp. 329, 339. Cited by Geikie, loc. cit., p. 373.

[231] An elaborate account of this earthquake is given by Dutton, Ninth Ann. Rept., U. S. Geol. Surv., pp. 209–528.

[232] Cross. Twenty-first Ann. Rept., U. S. Geol. Surv., Pt. II, Chap. V.

[233] Oldham. Report on the Indian Earthquake of June 12, 1897, p. 138. Mem. Geol. Surv. of India. Cited by Geikie, loc. cit., p. 374.

[234] Oldham, loc. cit., p. 80.

[235] Geikie. Text-book of Geology, 4th ed., p. 375.

[236] Ibid., p. 376.

[237] Forster, Seismology, 1877. Summarized in the Am. Geol., Vol. III, 1889, p. 182.

[238] The literature of seismology is very extensive. Some of the more general treatises are the following: Mallet, Brit. Assoc., 1847, Part II, p. 30; 1850, p. 1; 1851, p. 272; 1852, p. 1; 1858, p. 1; 1861, p. 201; and The Great Neapolitan Earthquake of 1857, 2 Vols., 1862; A. Perrey, Mém. Couronn. Bruxelles, XVIII (1844), Comptes Rendus, LII, p. 146; R. Falb, Grundzüge einer Theorie der Erdbeben und Vulkanenausbrüche, Graz, 1871, and Gedanken und Studien über den Vulkanismus, etc., 1874; Pfaff, Allgemeine Geologie als exacte Wissenschaft, Leipzig, 1873, p. 224; Schmidt, Studien über Erdbeben, 2d ed., 1879, and Studien über Vulkane und Erdbeben, 1881; Dieffenbach, Neues Jahrb., 1872, p. 155; M. S. di Rossi, La Meteorologia Endogena, 2 Vols., 1879 and 1882; J. Milne, Earthquakes and other Earth-movements (contains a bibliography), 4th ed., 1898; Seismology, ibid., 1898; Dutton, Earthquakes, 1904.

Records of earthquakes have been preserved more or less fully in several countries, especially in recent years. A few of the more accessible publications where these records are found are cited below: California earthquakes, Perrine, Bull. 147, U. S. Geol. Surv.; Earthquakes of the Pacific Coast, Holden, Smithson. Misc. Coll., No. 1087, 1898; Records of recent earthquake movements in Great Britain since 1890 are published by Davison in Quar. Jour. Geol. Soc., Geol. Mag., and Nature; Records of earlier earthquakes are found in the reports of the Brit. Assoc. (Mallet), in the Edinburgh New Philos. Jour., Vols. XXXI-XXXVI (Milne), and in Trans. of the Roy. Irish Acad., 1884 and 1886 (O’Reilly); The Earthquakes of Scandinavia have been recorded in volumes of the Geol. Fören, Förhandl.; Records of other continental European earthquakes are found in Gerland’s Beiträge zur Geophysik, 1895, 1900, and 1901; Neues Jahrb., 1865–71; Zeitschr. Naturwissen. (1884), (Credner); Bericht. k. Sachs. Geol. Wissen., 1889 and 1900 (Credner); Jahrb. Geol. Reichsanst., 1895 and 1897; Tschermak’s Min. Mitth., 1873, and later; Transactions of the Seismological Soc. of Japan. An index to these Transactions is given at the end of Milne’s Seismology.

[239] Antlitz der Erde. Vol. 1, p. 136.

[240] Eugene A. Smith. Underthrust Folds and Faults, Am. Jour. Sci., Vol. XLV, 1893, pp. 305–6.

[241] Manual of Geology, 3d ed., p. 23.

[242] For discussions of folds, see Van Hise, Sixteenth Ann. Rept. U. S. Geol. Surv., Pt. I, pp. 603–632; and Willis, Thirteenth Ann. Rept., Pt. II, pp. 217–296.

[243] Mechanismus der Gebirgsbildung, p. 213.

[244] Am. Nat., Vol. XIX, p. 257, 1885.

[245] Geol. Surv. of Canada, p. 33 D, 1886.

[246] Elements of Geology, 5th ed., p. 266.

[247] Van Hise. Bull. Geol. Soc. of Am., 1897, Vol. IX, p. 291.

[248] See Woodward’s address, Mathematical Theories of the Earth, Proc. Am. Assc. for Adv. Sci., 1889, pp. 59–63.

[249] Nat. Phil. Thompson and Tait, Pt. II, p. 477. See also Popular Lectures and Addresses, 1894, II, p. 313.

[250] Physics of the Earth’s Crust, Fisher, p. 95.

[251] Origin of Mountain Ranges, T. Mellard Reade, p. 125.

[252] Phil. Trans. Roy. Soc., Vol. 178, pp. 231–49.

[253] Amer. Jour. Sci., 1893, 3d series, Vol. 45, p. 7.

[254] Essentially the same as atmospheres.

[255] The pressures and densities here given are essentially the same as those previously worked out by others and already published. The temperatures are the results of recent preliminary computations made under the auspices of the Carnegie Institution, and are subject to change on further study. They are based on the assumption that the increase in density is due to compression. They are in general accord with the results previously reached by Dr. F. R. Moulton (see “A Group of Hypotheses Bearing on Climatic Changes,” by T. C. Chamberlin, Jour. of Geol., 1897, p. 674). The Rev. O. Fisher, in the Am. Jour. of Sci., 1901, p. 420, gives much higher results.

[256] Attention was called to this feature by Chamberlin in a paper before the Geol. Soc. of Am. at Rochester, December, 1901.

[257] These are reckoned by assuming that the temperature of no variation at 50 feet below the surface is 40° F.

[258] Am. Jour. of Sci., Vol. V, 1898, p. 161.

[259] Van Hise. Personal communication.

[260] Bull. 168 U. S. Geol. Surv., p. 14.

[261] Daniell’s Physics, p. 407.

[262] Heat. Tait, p. 225.

[263] All the feldspars are calculated as anorthite. Augite is used for hypersthene, ilmenite is included with magnetite, and all minerals are calculated as if of the isometric system.

[264] Physics of the Earth’s Crust, Chap. VIII.

[265] Penn Monthly, Philadelphia, May, 1876.

[266] The following conclusion by an eminent authority has come to our notice since this was written:

L’influence des marées océanienes sur la durée du jour est donc tout à fait minime et n’est nullement comparable à l’effet des marées dues à la viscosité et à l’elasticité de la partie solide du globe, effet sur lequel M. Darwin à insisté dans une series de Mémoires du plus haut intérêt. Par H. Poincaré, Bulletin Astronomique, tome XX (June, 1903), p. 223.

[267] On the Secular Changes in the Elements of the Orbit of a Satellite revolving about a Tidally-distorted Planet. Phil. Trans., Roy. Soc., Pt. II, 1880.

[268] Jour. Geol., Vol. VI, 1898, p. 65.

[269] Quar. Jour. Geol. Soc., Vol. 39, 1883, p. 140. Everett (Units and Physical Constants) gives 837 × 106 for steel, but as the modulus for granite seems low, we have taken the lower estimate for steel to avoid exaggerating the ratio between them.

[270] Nat. Phil. Thompson & Tait, Vol. II, p. 424, 1890.

[271] Computations made at the request of the authors. See also Fisher, Physics of the Earth’s Crust, p. 36.

[272] Of like import is the statement of Woodward—“If the crust of the earth were self-supporting, its crushing strength would have to be about thirty times that of the best cast steel, or five hundred to one thousand times that of granite.” Mathematical Theories of the Earth, Proc. Am. Assoc. for Adv. Sci., 1889, p. 49.

[273] It is assumed that the direction of the supporting thrust at the periphery of the dome is at every point parallel to the tangent to the domed surface. This is justified by symmetry in the case of a shell conforming to the sphericity of the earth, and in the other cases it would seem to be as favorable an assumption in the direction of high supporting capacity as can reasonably be made.

[274] Prepared at the authors’ request by W. H. Emmons.

[275] The terms are here used in their narrow technical sense. Extrusion is also used in a broad generic sense to indicate the whole process of outward movement.

[276] Gilbert. 14th Ann. Rept. U. S. Geol. Surv., Pt. I, p. 187.

[277] Gilbert, after a careful study of the moon’s topography, has suggested that the lunar pits may be indentations produced by infalling meteorites or planetoids, and has shown by experiment that pits of a similar type, with similar central cones, can be produced by impact. The Moon’s Face: A Study of the Origin of its Features. Presidential address, Phil. Soc. of Washington, 1892, Bull. Vol. XII, pp. 241–292.

[278] Structure and Distribution of Coral Islands.

[279] Corals and Coral Islands.

[280] Proc. Roy. Soc. Edin., Vol. X, pp. 505–18, and Vol. XVII, pp. 79–109; Nature, Vol. XXXII, p. 613; Narrative Chal. Exp., Vol. I, pp. 781–2.

[281] Bull. Mus. Comp. Zool., Vol. XVII, 1889.

[282] Ante, p. 22.

[283] Origin of Igneous Rocks. Phil. Soc. of Wash., Vol. XII, pp. 89–214.

[284] The Natural System of Volcanic Rocks. Cal. Acad. of Sci., 1868.

[285] Chemical News, April 9, 1897.

[286] Phil. Trans., 1873.

[287] Mechanics of Igneous Intrusion, Am. Jour. Sci., Apr., p. 269, and Aug., p. 107, 1903.

[288] Frank. Lehrbuch der Botanik, I, p. 576, 1892.

[289] Science, Vol. VI, p. 838, 1897. Zeitschrift für Anorganische Chemie, 1897.

[290] Reference works: Scott, Studies in Fossil Plants, 1900; Zeiller, Éléments de Paléobotanique, 1900; Potonié, Lehrbuch der Pflanzenpaleontologie, 1899; Seward, Fossil Plants, 1898; Solms-Laubach, Fossil Botany, 1887.

[291] Weed. Ninth Ann. Rept. U. S. Geol. Surv., 1887–88, pp. 613–76; also Bradley M. Davis. Science, Vol. VI, 1897, pp. 145–57.

[292] Cohn. Abhandl. Schles. Gesell. Naturwiss., Heft II, 1862.

[293] Deep Sea Deposits, p. 257.

[294] C. A. Davis. Jour. of Geol., Vol. IX, 1901, p. 491.

[295] Weed. Ninth Ann. Rept. U. S. Geol. Surv., 1887–8.

[296] Reference books: Zittel’s Text-book on Paleontology, translated and edited by Eastman; Williams’ Geological Biology; Nicholson’s Manual of Paleontology.

[297] After Zittel in the main.

[298] S. W. Johnson, How Crops Feed, p. 47.

[299] Reference works: Plant Relations, Coulter, 1900,—a convenient elementary work; Schimper, Pflanzengeographie, 1898; Warming, Lehrbuch der oekologischen Pflanzengeographie, 1896; Cowles, Botanical Gazette, Vol. XXVII, 1898.

[300] One of the earliest attempts to map these and develop their significance and value is found in Vol. II, Geol. of Wis., 1873–77, Native Vegetation, pp. 176–87.

[301] Chamberlin. A Systematic Source of Evolution of Provincial Faunas, Jour. of Geol., Vol. VI, 1898, pp. 597–609.

[302] Wallace. Island Life.

[303] For data, see Walther’s Einleitung in die Geologie, pp. 35–45.

Transcriber’s Notes: