expanding when freezing,237;epoch,92,93,246;floating,242;made soils rarely fertile,241;mass, greatest, in Greenland,226,227;moulded by pressure,215;streams,continental,225,226;of the mountains,225;of the Himalayan Mountains,234.Icebergs,242,243;indicating oceanic currents,243.Iceland, volcanic eruptions in,297,298.Instruments, first, astronomical,10,11.Inventions, mechanical, aiding science,22.Islands,84,272;continental,84;in the deeper seas made up of volcanic ejections,272;volcanic,272.Jack-o'-lantern,167.Jupiter,gaseous wraps of,97;path of the earth affected by,59,60;the largest planet of the sun,69.Kames,325.Kant, Immanuel, and nebular hypothesis,34.Kaolin,324.Klondike district, cold in,243,244.Krakatoa,eruption of,298-300;effect of, on the sea,299;effect of, on the sun,300.Lacolites,306.Lacustrine beds,351.Lagoons, salt deposits found in,200.Lake basins,formation of,200,201;bogs,331,333,334;deposits,350,351.Lakes,199-206;effect of, on the river system,205;fresh-water,145;formed from caverns,202;great, changing their outlets,205;of extinct volcanoes,203;temporary features of the land,203;volcanic,203.Lands,great, relatively unchangeable,96;table,91;movements resulting in change of coast line,351,352;shape of the seas and,83,84;accounting for the changes in the attitude of the,95;and water, divisions of,84;dry, surface of,85;general statement as to the division of the,83,84;surface, shape of the,85;triangular forms of great,90.Latitudes, horse, troublesome to mariners,104.Laplace and nebular hypothesis,34.Lava,266-268,270,271,292,293,295,296,303,304;flow of, invading a forest,268;from Vesuvius,293;of 1669,295,296;temperature of,295,296;incipient,304;outbreaks of,292,303;stream eaves,292,293.Law, natural,Aristotle and,3;of gravitation,4;of the conservation of energy,23.Leaves, radiation of,160.Length of days affected by tidal action,131.Level surfaces,91.Life, organic, evolution of,15,16.Light, belief of the ancients regarding,42.Lightning,24,164-168;noise from,166;proceeding from the earth to the clouds,165;protection of buildings from,165;stroke, wearing-out effect of,165.Limestones,353,357,358,360,364;formation of,357,360.Lisbon, earthquake of, 1755,368,369.Lowell, Mr. Percival, observations on Venus,64.Lunar mountains near the Gulf of Iris,397.Mackerel sky,35.Mallet, Mr. Charles, and the study of earthquakes,382,383.Man as an inventor of tools,10.Mangroves,340;diagram showing mode of growth,340;marshes of,339.Map of glaciers and moraines near Mont Blanc,217;of Ipswich marshes,338.Mapping with contour lines,27.Maps,desirable, for the study of celestial geography,77;geographic sketch,26,27.Marching sands jeopardizing agriculture,123.Marine animals, sustenance of,361-363;deposits,325-327,349,356;marshes,336-340;waves caused by earthquakes,387.Mars,65-67,84,97;belief that it has an atmosphere,65;canals of,67;gaseous wraps of,97;more efficient telescopes required for the study of,67;nearer to the earth than other planets,65.Marshes,mangrove,339;map of Ipswich,338;marine,336-340;deposits found in,336;of North America,337;on the coast of New England,339;phenomena of,167,168;tidal, good earth for tillage,337;tidal, of North America,340.Mercury,55,63,78;nearest to the sun,63;time in which it completes the circle of its year,55.Meteorites,47,48;kinship of comets and,48.Meteors,47;falling,47;composition of,48;flashing,39,40,47;speed of,47;inflamed by friction with air,99.Methods in studying geology,400.Milky Way,45;voyage along the path of the,44,45.Mineral crusts,328,329;deposits,308.Moon,38,395-400;absence of air and water on the,399;attended by satellites,57;attraction which it exercises on the earth,62;curious feature of the,397;destitute of gaseous or aqueous envelope,397;diameter of the,399;imaginary view of the earth from the,81;"libration" of the,398;made up of circular depressions,396,397;movements of the,78;no atmosphere in the,97;parting of the earth and,396;position of the, in relation to the earth,62;tidal action and the,131;tides of the,126,127;why does the sun not act in the same manner as the,78.Moraines,216,218,229,230;map of glaciers and, near Mont Blanc,217;movements of the,216-218;terminal,228.Moulin,219.Mount Ætna,288-310;lava yielding,290,293,294;lava stream caves of,292,293;more powerful than Vesuvius,297;peculiarities of,291,292;size of,289-291;turning of the torrents of,295.Mountain-building,90-93,304;folding,86,87,90,365;attributed to cooling of the earth,88;growth,392;Swiss falls,174;torrents, energy of,177.Mountains,85,86,89,90-93;174-178;form and structure of,86;partly caused by escape of heat from the earth,89;sections of,87.Mount Nuova, formation of,284.Mount Vesuvius,263-285,288,289,293,302,381;description of the eruption of, ina.d.79,277-280;diagrammatic sections through, showing changes in the form of the cone,283;eruption of, in 1056,281;in 1882-'83,264,266;eruption of, in 1872,282;eruptions of, increased since 1636,282;flow of lava from,285;likely to enter on a period of inaction,282,283;outbreak of, in 1882-'83,264,266.Naples, prosperity of the city,289.Nebular hypothesis,34,35,39,52.Neptune,70.Névé, the,214;no ice-cutting in the region of the,224.Newcomb's (Prof.) belief regarding the heat of the sun,52.Niagara Falls,191,192,204;cutting back of,204.North America,changes in the form of,91,92;triangular form of,90.Ocean,average depth of the,89;climatal effect of the,147;currents,145;effect of, on migration,156;effect of, on organic life,154;floor,85,93;hot and cold currents of the,102;sinking of the,93,94;the laboratory of sedimentary deposits,351;depth of the,89,126.Oceanic circulation, effect of, on the temperature,152.Oceans and continents,83.Orbit,alterations of the, and the seasons,60,61;changing of the,59-63;shape of the,61-63.Organic life,315,317,321,352,353,363;action of, on the soil,317,321;advantages of the shore belt to,363;development of in the sea,352,353;effect of ocean currents on,154;processes of, in the soil,315;decay of, in the earth,321.Orion,46.Oscillations of the shores of the Bay of Naples,287.Oxbow of a river,182,183.Oxbows and cut-off,182.Pebbles,action of seaweeds on,143;action of the waves on,142,144.Photosphere,74.Plains,86;alluvial,91,179,182,184-186,325;history of,91;sand,325.Planets,38;attended by satellites,57;comparative sizes of the,68;experiments illustrating consolidation of disseminated materials of the sun and,40;gaseous wraps of,97;important observations by the ancients of fixed stars and planets,43;movements of,57-61;outer,78;table of relative masses of sun and,77.Plant life in the Sargassum basins,156.Plants and animals,protection of,by mechanical contrivances,364;and trees, work of the roots of, on the soil,316,317;water-loving,181;forming climbing bogs,332.Polar axes, nodding movement of,54.Polar snow cap,66.Polyps,155,353.Pools, circular,203.Prairies,340,342.Radiation of heat,159.Rain,152,156,164,168,170,328,330;circuit of the,156-168;drops, force of,169,170;spheroidal form of,170;electrical action in the formation of snow and,164;work of the,171.Realm, unseen solar,75.Reeds,332.Religion,conflict between science and,20,22;struggle between paganism and,21.Rivers anddébris,183;changes in the course of, in alluvial plain,182;deposition of, accelerated by tree-planting,181;great, always clear,205;inundation of the Mississippi, eating away land,182;muds,222;newly formed, cutting a cañon,195;of snow-ice,211;origin of a normal,173;oxbow of a,182,183;sinking of,199;swinging movement of,179-181;river-valleys,193,194;diversity in the form of188-191.Rocks,145;accidents from falling,174;cut away by sandstones,188;divided by crevices,252;duration of events recorded in,389,390,ejection of, material,311;falling of,174-176;formation of,262,263;from the present day to the strata of the Laurentian,390;migration of,291;poised, indicating a long exemption from strong earthquakes,388;rents in,252,253;stratification of,349,350,352,365,390;testimony of the, in regard to glaciers,228;under volcanoes,303;variable elasticity of,366;vibration of,367,368;rock-waste, march of the,343;water,250,267.Rotation of the earth affected by tides,130;of the planetary spheres on their axes,56.Salicified forests,124.Salt deposits formed in lagoons,200;found in lakes,199-200.Sand bars,183;endurance of, against the waves,145;hills, travelling of,123;marching,123;silicious stones cutting away rooks,188.Satellites,53,54;motions of, about their centres and about the sun,53,54.Saturn,38,53,57,396;cloud bands of,70;gaseous wraps of,97;path of the earth affected by,59,60.Savages, primitive, students of Nature,1.Scandinavia, changes on the coasts of,96.Science,advance of, due to mechanical inventions,22;astronomy beginning with,10;chemical, characteristics of,14;conflict between religion and,20,22;conflict between the Roman faith and,20;mechanical inventions as aids to,22,23;modern and ancient,4;natural,5,6;of botany in Aristotle's time,14;of physiology,15;of zoölogy in Aristotle's time,14;resting practically on sight,10.Scientific development,historic outlines of,17;