Of 
 CALIFORNIA 
 
 Presented to the 
 
 Department of Geological Sciences 
 University of California at 
 Berkeley, January 24, 1935 
 
 By 
 
 ABTHITR SIDMSY HUSY 
 (Graduate Student) 
 
 O ~ 4 ^. 
 
 ARTH SCIENCES LIBRAR 
 
WALKS AND TALKS 
 
 IN 
 
 GEOLOGICAL FIELD. 
 
 BY 
 
 ALEXANDER WINCHELL, LL.D.. 
 
 /,' 
 
 PROFESSOR OF GEOLOGY AND PALEONTOLOGY IN THE UNIVERSITY 
 OF MICHIGAN. 
 
 NEW YORK: 
 CHAUTAUQUA PRKSS. 
 
 C. L. S. C. DEPARTMENT, 805 BROADWAY. 
 1886. 
 
The required books of the C. L. S. C. are recommended 
 by a Council of six. It must, however, be understood that 
 recommendation does not involve an approval by the Coun- 
 cil, or by any member of it, of every principle or doctrine 
 contained in the book recommended. 
 
 (^s <^aV <f \ c.^ ( OC i --c- ^S 
 
 Copyright, 1886, by PHILLIPS & HUNT, 805 Broadway, New York. 
 
PREFACE. 
 
 THIS work attempts to hold a position between text- 
 books and books of light reading. The formal text- 
 book would not suit the class of readers addressed. The 
 style of light reading would have been unworthy of the 
 theme, and would not have supplied the substantial infor- 
 mation here intended. The writer has often felt that 
 graphic illustrations would have rendered portions of the 
 text more intelligible, and therefore, more entertaining ; 
 but these would have enhanced the cost of the book 
 beyond limits which for other reasons seemed desirable. 
 The method of treatment is simple. The reader be- 
 gins with the familiar objects at his very door. "His 
 observations are extended to the field, the lake, the tor- 
 rent, the valley, and the mountain. They widen over the 
 continent until all the striking phenomena of the surface 
 have been surveyed. Occasionally, trains of reasoning 
 suggested by the facts are followed out until the outlines 
 of geological theories emerge. The course of observation 
 and reasoning then penetrates beneath the surface. The 
 various formations and their most striking fossils are de- 
 scribed, first in descending order, to the oldest. We find 
 here indications of heat which stimulate speculation and 
 bring out the grounds of a nebular theory of world- 
 origin. From this starting point, the treatment now 
 handles the subject in historical order, weaving into a 
 
 .931177 
 
4 PREFACE. 
 
 narrative, the dry facts previously noted. Reaching the 
 end of the history, the treatment pauses for retrospect 
 and reflection ; and here are brought to view some of the 
 higher and more abstruse thoughts connected with the 
 subject of the book. 
 
 It is hoped the perusal of this work may impart some 
 clear conceptions of that grand range of scientific truths 
 with which it deals. It is hoped, also, that a relish may 
 be stimulated which will seek its gratification in the 
 scholarly study of works of higher range and more 
 exacting method. 
 
 THE AUTHOR. 
 
 ANN ARBOR, March, 1886. 
 
CONTENTS. 
 
 I. FACTS; 
 
 OR, 
 
 THE RECORD GIVEN US TO READ. 
 
 tljc 
 
 PAGE. 
 I. THE GEOLOGY AT OUR DOORS, ........... 9 
 
 Surface Materials. 
 
 II. LOST ROCKS, ................... 13 
 
 Bowlders. 
 
 III. THE GRAVEL PIT, ................. 18 
 
 Arrangement of the Drift. 
 
 IV. AMONG THE GLACIERS, .............. 24 
 
 Geological Action of Glaciers. 
 V. THE HILLSIDE SPRING AND ITS WORK, ....... 30 
 
 Subterranean Waters and their Deposits. 
 
 VI. INTRODUCTION TO THE ROCKS, ........... 35 
 
 Kinds of Minerals and Stones. 
 
 VII. THE FLOODS OP THE GREAT LAKES, ........ 41 
 
 Lacustrine Deposits and Terraces. 
 
 VIII. THE MUD FLAT, .......... . ...... 45 
 
 Sedimentation. 
 
 IX. THE RIVER GORGE, ... ............. 50 
 
 Erosion. 
 
 X. A WALK UNDER THE SEA, ............ 56 
 
 What goes on in the Ocean Depths. 
 
 XI. BY THE ROCKY WALL, .............. 62 
 
 Strata and their Classification. 
 
 XII. MYSTERIOUS FORMS OF LIFE, ............ 67 
 
 Fossils. 
 
CONTENTS. 
 
 PAGE. 
 
 XIII. COURSES OF THE EARTH'S MASONRY, ...... 74 
 
 How the formations are arranged. 
 
 XIV. A WALK IN THE YELLOWSTONE PARK, ..... 79 
 
 Thermal Waters. 
 
 XV. AMONG THE VOLCANOES, ............ 85 
 
 Indications of Internal Fires. 
 
 XVI. FROZEN SEAS OF LAVA, ........ . . . . 91 
 
 Ancient Lavas. 
 
 XVII. IMPRISONED HEAT, .............. 96 
 
 Internal Condition of the Earth. 
 
 XVIII. THE UNSTABLE LAND, ............. 102 
 
 Phenomena and Causes of Earthquakes. 
 
 XIX. THE FRAMEWORK OF THE MOUNTAINS, ..... 108 
 Mountain Structures. 
 
 XX. How THE MOUNTAIN FRAMEWORK is REARED . . 113 
 Mountain Formation. 
 
 XXI. DOWN IN A MINE, ............... 119 
 
 Modes of Occurence of the Metals. 
 
 XXII. THE KING OF METALS, ............ 125 
 
 Iron and Its Geology. 
 
 XXIII. THE CRYSTALS OF THE SEA, .......... 130 
 
 Salt and Gypsum. 
 
 XXIV. LIQUID SUNLIGHT, ........... .... 135 
 
 Petroleum. 
 
 XXV. GASEOUS SUNLIGHT, ...... ..... 141 
 
 Natural Gas Its Wonders and its Geology. 
 
 XXVI. SOLIDIFIED SUNLIGHT, ............. 149 
 
 Coal and Coal-Beds. 
 
 3^ttt<m0 th* 
 
 XXVII. MONSTERS OF A BURIED WORLD, ........ 154 
 
 Extinct -Quaternary Mammals. 
 
 XXVIII. THE CEMETERIES OF THE BAD LANDS, ..... 162 
 Tertiary Fossils. 
 
 XXIX. LESSON FROM A LUMP OP CHALK, ...... 167 
 
 Mesozoic Rocks and Fossils. 
 
CONTENTS. 7 
 
 PAGE. 
 
 XXX. LONE BURIALS IN THE COAL LANDS, 173 
 
 Coal Measure Fossils. 
 
 XXXI. TERRIBLE FISHES AND THEIR COMPANIONS, . . . 178 
 Remains of the Devonian Age. 
 
 XXXII. ANCESTRY OF THE PEARLY NAUTILUS, 184 
 
 Silurian Remains. 
 
 XXXIII. THE KING-CRAB'S GRANDFATHER AND OTHER 
 
 GRANDFATHERS, 190 
 
 Cambrian Fossils. 
 
 XXXIV. EARTH'S DEEPEST GRAVES, 197 
 
 The Eozoic Animal. 
 
 XXXV. AN EARLIER BEGINNING, 202 
 
 Intimations of a Fiery Mon. 
 
 II. HISTORICAL GLIMPSES; 
 
 OB, 
 
 STORY OF THE WORLD SET IN ORDER. 
 
 XXXVI. GATHERING WORLD-STUFF, 208 
 
 Wandering Germs of Worlds. 
 
 XXXVII. THE WHIRLING FIRE-MIST, 214 
 
 Nebular Theory of World Origin. 
 
 XXXVIII. THE PRIMEVAL STORM, 219 
 
 Origin of the Ocean. 
 
 XXXIX. THE WAR IN THE OCEAN, 224 
 
 The Earliest Strata. 
 
 XL. THE WORLD WITHOUT A BACK-BONE, ...... 230 
 
 Reign of Invertebrates. 
 
 XLI. THE DYNASTY OF FISHES, 236 
 
 Devonian and Carboniferous Times. 
 
 XLII. SCENES FROM THE COAL PERIOD, 241 
 
 How the Coal-Beds were Formed. 
 
 XLIIL THE REPTILE MONARCHIES, 246 
 
 Mesozoic Events. 
 
XLIV. 
 
 XLV. 
 
 CONTENTS. 
 
 PAGE. 
 
 MAMMALIAN EULE, . . , 252 
 
 Csenozoic Times. 
 
 ANTICIPATION AND RETROSPECT IN LIFE-PLANS, . 258 
 Comprehensive Types. 
 
 XLVI. THE THROES OP THE CONTINENT, . 264 
 
 How the Land Grew. 
 
 XL VII. THE REIGN OF ICE, 270 
 
 Continental Glaciation. 
 
 XLVIII. A GEOLOGIC SPRING TIME, 275 
 
 Incidents of the Champlain Epoch. 
 
 
 
 XLIX. THE EARTH RECEIVES HER KING, 281 
 
 Advent of Man. 
 
 III. RETROSPECT; 
 
 OB, 
 
 HOW THE STORY OF THE WORLD IMPRESSES US. 
 
 L. THE ABYSS OF CENTURIES, . 288 
 
 The Age of the World. 
 
 LI. THE METHOD OF CREATION, 294 
 
 The Question of Evolution. 
 
 LII. THE HUMAN FACTOR IN THE WORLD'S VICISSI- 
 TUDES, 300 
 
 Man in the Light of Science. 
 
 LIII. MIND IN MATTER, 306 
 
 The Interpretation of Nature. 
 
 LIV. ONE EMPIRE, . . . . ' ' . 312 
 
 The Unity of Nature. 
 
WALKS AND TAIiRS.O 
 
 ^ " ' ' J, i* 
 
 I. 
 
 FACTS; 
 
 OR, THE RECORD GIVEN U TO READ. 
 
 AMONG THE ROCKS. 
 
 I. THE GEOLOQY A.T OUR DOORS. 
 
 SURFACE MATERIALS. 
 
 COME, John and Jennie come, George and Julia let us 
 have a talk about GEOLOGY. Come, John's mother and 
 aunt come every body that wishes we shall find some of 
 the most delightful things to talk about which any body ever 
 heard of. Now "Geology" may sound like a hard word; 
 and perhaps you have no curiosity to know any thing about 
 it. But do not decide too soon, for if you know nothing 
 about Geology, you can 't know what interest there is in it. 
 Take my word for to-day you will find the subject easy and 
 delightful. 
 
 We shall travel all over the world. We shall climb over 
 mountain-cliffs and descend into deep mines. We shall go 
 down under the sea, and make the acquaintance of creatures 
 that dwell in the dark and slimy abysses. We shall split the 
 solid rocks and find where the gold, the silver, and the iron 
 are hidden. We shall open the stony tombs of the world's 
 mute populations. We shall plunge through thousands of 
 ages into the past, and shall sit on a pinnacle and see this 
 
10 WALKS AND TALKS. 
 
 planet bathed in the primitive ocean ; boiled in the seething 
 water ; roasted in ancient fires ; distorted, upheaved, moulded, 
 and reshaped again and again, in a long process of prepara- 
 tion to feecbjrfe; ;fi;t for us to dwell upon it. We shall see a 
 long prbcessio'n *oT' 'strange creatures coming into view and 
 li.-appeanpgj siich a menagerie of curious beasts and crawl- 
 ing and cfe'epirTg* aird flying things as never yet marched 
 through the streets of any town. And what is most wonder- 
 ful of all, we shall plunge through thousands of ages of com- 
 ing events, and sit on our pinnacle and see the world grow 
 old all its human populations vanished its oceans dried 
 up its sun darkened, and silence and midnight and Winter 
 reigning through the entire province in which a sisterhood of 
 planets at present basks in the warmth and light of a central 
 and paternal sun. 
 
 . Do you feel no curiosity over these wonderful themes ? 
 These all belong to Geology. Come, let us begin. 
 
 But we must begin at the beginning. Those who go on 
 long and pleasant journeys have to start from their own door- 
 steps. Geology tells all about this world. The world is here 
 under our feet. It is in the garden and along the road-side, 
 and in the field, and on the shore where the summer ripples 
 sing lullabies to the sleepy crags, and winter storms tear 
 them from their resting-places. No summer ripples or wintry 
 storms are here ; but the solid land is here. Let us walk up 
 this hill-slope and sit where we may get an outlook over a 
 little piece of the world's surface. 
 
 What is there, now, within reach of our vision that we 
 can distinguish and describe and say that it belongs to the 
 world is a part of the world ? Whatever it may be, it is a 
 geological fact. It is a part of the science of geology. Now, 
 here is this hill-slope, and the soil and stones which make it. 
 Back of us the hill rises to a higher level. Perhaps brown 
 cliffs frown near its summit; and there are huge, heavy trees 
 upborne five hundred feet above the town. But, in the op- 
 posite direction, there is the landscape. That is a geological 
 fact. With all its scenic beauty, that is geology, at founda- 
 
GEOLOGY AT OUR DOORS. 11 
 
 tion. The houses and the herds, the wheat-fields and the 
 gardens these are accessories. But the dark, beetle-browed 
 ridge which skirts the horizon that is nature's. The green 
 forest which glides down to the field borders ; the stream which 
 winds across the landscape, and rises and falls with the rains ; 
 the low swells and the valleys between ; the outcropping ledge 
 in the field, and the loose stone by the road-side these belong 
 to nature. There, in the distance, flies the train of steam-cars, 
 its iron-bound way has been cut through hill and rock-mass, 
 and opens to our view something of the hidden material 
 which goes to form the world. There is the meadow, with its 
 green turf and deep, dark soil. The gully scored in the hill- 
 side by the summer storm, and the train of stones and sand 
 at its foot which the water tore from their hiding-places be- 
 neath the soil. Up the stream we see the tamarack swamp 
 or the open marsh, through which the head-waters flow the 
 head-waters of the main stream or of some small tributary. 
 There, just beyond, is the little lake or pond, sleeping in its 
 green-fringed nest, and looking out on the grass-covered 
 slopes and the blue sky. 
 
 How charming is all this scenery ! How many times, im- 
 bued with the love of nature, we have strolled on the borders 
 of this quiet lakelet, or lounged on the green slope, which 
 seemed set, like an amphitheater, to accommodate the visitor, 
 who loves to look upon the scene. Perhaps, as urchins stray- 
 ing from school, or getting the most out of a Saturday holiday, 
 we have angled along this brook, or paddled our skiff over 
 this pond. Perhaps in wonderment we have seen the artist 
 from the city, with easel and brush reproducing on canvas 
 the beauty of this simple landscape, thinking to win a prize 
 in the Academy of Art, or at least to afford the pent-up 
 dwellers in the dusty town the luxury of knowing how lav- 
 ishly the beauties of nature are strewn before the gaze of those 
 who dwell here in this agricultural vale in this quiet hamlet 
 which Providence has made our home. 
 
 This is all geology. We are in the midst of it. We have 
 been enchanted by it before we knew its name. We have 
 
12 WALKS AND TALKS. 
 
 admired the forms fashioned in beauty by the hands of the 
 geological forces before we knew that it had a geological 
 origin, or possessed any geological significance, or had passed 
 through long ages of preparation. We have been like chil- 
 dren born in the parental dwelling, reared in the midst of its 
 comforts and adornments, without once thinking that, before 
 we were born, some mind planned the dwelling, some hands 
 reared its walls, laid its floors, and fashioned every doorway 
 and casing. Now, this terrestrial dwelling, with all its beau- 
 ties and conveniences, its wonders and sublimities, is something 
 to set us thinking; just as we reflected, when the thought first 
 came into our minds, that father's house has had a history, 
 and was the product of study and labor, which we had never be- 
 fore considered. The green slope was made ; the pretty lake was 
 scooped out ; the swelling hill was shaped ; the dark mountain 
 was upbuilt, its foundations were laid, its vast weight has 
 been sustained and is to-day sustained by some support, with 
 strength proportioned to the requirement. It is time for us to 
 come to a realization of these facts. 
 
 We may begin in this very spot to inquire how this ter- 
 restrial home was fashioned. It was made without hands, but 
 not without the use of the same forces of nature and proper- 
 ties of matter as were employed in the building of our paternal 
 dwelling. Its plan was not drafted on paper and carried out 
 under the direction of a builder, who issued his orders in 
 audible tones ; but our terrestrial abode is built under a plan 
 just as real and just as intelligible, and is just as truly a fit 
 subject for study. There is this difference, that we may ar- 
 rive at a complete understanding of the plan, and purposes, 
 and modes of construction of the paternal home ; but of the 
 terrestrial home we can only arrive at an incomplete under- 
 standing. As far as we proceed, the methods of understand- 
 ing and interpreting are the same ; but the whole plan, in its 
 depth, and breadth, and complications surpasses our powers, 
 and we must, like young children, content ourselves with a 
 comprehension of some of the most obvious things sure that 
 if our powers were loftier, we might proceed in the same way 
 
LOST ROCKS. 13 
 
 to understand more difficult things in the plans and methods 
 of world-making. 
 
 If we decide to interest ourselves in the inquiry, How the 
 world was made and what it has become, we must first give 
 attention to the materials of which it is composed. It is a 
 stone dwelling; it is imperishable at least as imperishable 
 as granite foundations and massive courses of masonry can 
 render a structure. Here are, indeed, beds of gravel and 
 sand, overspreading the greater part of the country. These 
 are not firmly consolidated, and are easily moved out of place. 
 But they are like the gravel used on the roofs of some build- 
 ings a very insignificant part of the whole. Underneath 
 these loose materials we shall find the solid and enduring 
 foundations. But the study of the loose surface materials is 
 full of interest, because their presence renders the earth hab- 
 itable. What sort of a home for man or beast would this 
 planet be, if all the loose surface beds were cleared off down 
 to the rocky floor on which they rest? Did you ever hear 
 that question asked before ? We must, by all means, begin 
 with the stones, and sands, and clays, which lie upon the sur- 
 face, or near the surface, and try to ascertain what they are 
 and how they are arranged, and of what use they are to man. 
 Do you think we had better proceed? 
 
 II. LOST ROCKS. 
 
 BOWLDERS. 
 
 WHO cares for a cobble-stone ? It is a kind of nuisance 
 anywhere so most people think. The farmer would be glad to 
 have every one of them carted from his fields. I have seen land 
 so thickly covered by them as to be almost impossible to cul- 
 tivate. In some regions near the coast, in New England, the 
 loose rounded stones lie so close over hundreds of acres that 
 I have traveled by simply stepping from stone to stone. 
 
 You will notice that cobble-stones are of various sizes. In 
 fact, it is difficult to state where a cobble-stone is small enough 
 
14 WALKS AND TALKS. 
 
 to be called a " pebble," and just where it is too large to be a 
 cobble-stone. Pebbles differ from them only in size. Pebbles 
 are hard and rounded, and seem formed of the same kinds of 
 rocks ; and the large, rounded, loose stones, which lie scattered 
 over the earth's surface, are in every respect only a larger 
 style of cobble-stones. It is plain that these are all one class 
 of rocks. So it has been decided ; and geologists call them 
 bowlders. This is an old name used by common people before 
 the science of geology existed, because these stones are rounded 
 like balls or boUs; and, being loose on the surface, are apt to 
 be bowled about. Even grains of gravel and sand appear to 
 be of the same nature as bowlders. You will also notice, 
 especially, that these rocks are all separate and detached, as 
 well as rounded, and they are of various colors and mix- 
 tures of colors. They are apparently different kinds of 
 rocks, which by some means have been brought promiscuously 
 together. Ledges of rock, which you must have noticed many 
 times, are generally all one kind of rock. They extend long 
 distances, and continue under the earth. Should a ledge of 
 rocks become broken up, and the fragments, large and small, 
 have their angles rounded off, and the whole then be scattered 
 over a township, far from the ledge, the result would be much 
 like what we see in our actual bowlders. From all we know 
 of rocks we are constrained to believe that our bowlders are 
 rounded fragments of broken up ledges. But where are the 
 ledges? Not in the next township or county. Perhaps not in 
 the next state or province. They have strayed far away from 
 their native ledges. They are " lost rocks." Now, it would 
 be very interesting to know where the parent ledges are ; and 
 it is curious how these fragments have been transported so far, 
 and how they became so rounded, instead of remaining angu- 
 lar, like the stones blasted from a quarry. 
 
 Indeed, the more we think about this, the more astonishing 
 the facts appear ; for we call to mind that just such bowlders 
 are scattered all over our northern states, and they lie buried 
 beneath the surface in countless numbers. And the very sand 
 and gravel, to the depth of many feet, is only the same kind 
 
LOST ROCKS. 15 
 
 of material in a finer state. What an incalculable amount of 
 work has been accomplished in transporting all these materials 
 so far that the places from which they came have been lost, 
 and can not be found. Suppose it were necessary to cart all 
 the loose stuff on a township to a distance only one mile fur- 
 ther, on what terms do you think the contract would be 
 taken? But all that stuff has been moved not one mile 
 alone, but many miles, to a certainty. And not alone the 
 stuff on a township, but the stuff on ten thousand townships. 
 The work was not done, you say, by the slow process of haul- 
 ing in carts. No, indeed ; but it was done somehow, and it 
 is the same job whether performed by Nature's method or by 
 human muscle. Think of that. 
 
 Now, what do you imagine was Nature's method? Would 
 it not be a grand discovery if we could find out? It was 
 Agassiz that ascertained this, and the discovery gained him 
 great fame. But there were others who came very near to 
 the same discovery. Suppose we could stand by and see 
 Nature in the midst of the job carting and dumping on the 
 bare surface of the rocks, the gravel and sand and clay so in- 
 dispensable to render the surface of the earth habitable for 
 man or beast or plant. I think we should consider it a grand 
 revelation of the method and mind of the Author of nature. 
 I am happy to assure you that we have found out pretty pre- 
 cisely how this immense and beneficent work was done ; and 
 this knowledge is a part of geology, and we are intending to 
 talk these matters over until you grasp the knowledge. That 
 is, we shall put you where you will be as a bystander gazing 
 on the progress of the great work as Nature herself car- 
 ries it on. 
 
 Many bowlders attain to dimensions which are truly enor- 
 mous. The largest are found in northern New England and 
 Canada. As we proceed southward, the average size dimin- 
 ishes, and south of the parallel of Cincinnati, bowlders are 
 entirely wanting, except along the Appalachians. In New 
 Hampshire are many immense bowlders, which have excited 
 the wonder of all who have seen them. Several of these have 
 
16 WALKS AND TALKS. 
 
 been described and figured by Professor C. H. Hitchcock in 
 his Report on the Geology of New Hampshire. The Churchill 
 Rock of Nottingham is 62 feet long, 40 feet wide and 40 feet 
 high. It contains 75,000 cubic feet, and weighs 6,000 tons. 
 Close by is Chase Rock, 40 feet long, 40 feet high and 30 
 feet wide. Vessel Rock, in Gilsum, now split by frost, 
 weighed 2,286 tons. The Green Mountain Giant, in Whit- 
 tingham, Vermont, weighs 3,000 tons; and a bowlder for- 
 merly existing at Fall River, Massachusetts, weighed 5,400 
 tons. At St. Ignace, in the Upper Peninsula of Michigan, 
 lies a porphyry bowlder 25 feet in height. Mr. G. M. 
 Dawson, in his report on the geology of the North-west Terri- 
 tory, describes a quartzite bowlder 42 feet long, 40 feet wide 
 and 20 feet high, and another nearly as large. It appears 
 that the greater part of North America, down to the latitude 
 of Cincinnati, is overstrewn by incoherent materials contain- 
 ing bowlders. The situation is similar in Europe ; and there, 
 also, certain "lost rocks" or "erratics" attain vast dimen- 
 sions. The " Pierre a bot (or Toad-stone), on the Jura Moun- 
 tains, about two miles west of Neufchatel, contains 40,000 
 cubic feet, and weighs 3,000 tons. As far south as the Lake 
 of Como, bowlders of large size are very frequently en- 
 countered. 
 
 Often these lost rocks lie perched on the summits of sharp 
 cliffs ; and sometimes we find them so nicely poised that the 
 strength of a man suflices to give them a tilt. They are then 
 called " rocking stones." In Hanover, New Hampshire, half 
 a mile east of Dartmouth College, is a rocking stone 12 feet 
 long, 10 feet wide, 5^- feet thick, containing 480 cubic feet. 
 In Goffstown is one 8 feet high and 42 feet in circumference. 
 In Barre, Massachusetts, is one having a smaller bowlder on 
 its back, which, when in motion, suggests the idea of a 
 child's rocking horse. One in Fall River, poised on granite, 
 weighs 160 tons. 
 
 We find bowlders at various altitudes, from the level of 
 the sea, to the height of perhaps six thousand feet ; but above 
 this, though rock fragments are extremely numerous, they 
 
LOST ROCKS. 17 
 
 are mostly angular, and appear to be derived from rocky 
 ledges close by. They are not " lost rocks." The summit of 
 Mt. Washington is covered by a bed of angular fragments, 
 and such fragments are common for two thousand feet below 
 the summit. Lower than this, rounded bowlders are abun- 
 dant. Professor C. H. Hitchcock, however, thinks he finds 
 real transported rocks to the very summit. The great quartz- 
 ite bowlder in the North-west Territory, Canada, is 3,250 feet 
 above sea-level. Many others in that part of the continent 
 are up to 4,400 feet in elevation ; and, in one region, attain 
 5,280 feet. Some erratics on the flanks of the Sweet Grass 
 Hills lie at an elevation of 4,660 feet. The Pierre a bot, in 
 Switzerland, is 800 feet above Lake Neufchatel, which lies 
 itself 1,427 feet above sea-level. 
 
 We observe, in passing over the country, that the larger 
 bowlders are northward ; while toward the south, their aver- 
 age size diminishes to cobble-stones, and finally, all indications 
 of transported rocks disappear. Since we have concluded 
 that all these lost rocks have been removed from extensive 
 ledges somewhere, it seems probable that the direction of these 
 ledges is to the north. We notice also, that bowlders of any 
 particular kind become more numerous, as well as larger, as 
 we proceed northward. In fact, in some cases, by following 
 up a train of bowlders of a particular kind, we trace them to 
 their origin. That origin is often sixty or one hundred miles, 
 or even two hundred miles away. Such are the distances to 
 which the forces of Nature have moved much of these inco- 
 herent materials. 
 
 It is not always possible to trace bowlders to their source 
 by following back a train. But we can always consider where 
 is the nearest locality of bed-rocks of the same kind as any 
 particular bowlders. For instance, in Connecticut, we can 
 find bed-rocks sometimes, in the near vicinity, but at other 
 times, not farther away than Massachusetts. In Ontario, the 
 nearest sources of the bowlders are in the regions east and 
 north of Georgian Bay. At Chautauqua, the nearest bed- 
 rock for the hard bowlders is beyond Lake Ontario and Lake 
 
 2 " 
 
18 WALKS AND TALKS. 
 
 Simcoe. In Michigan, the nearest source is north of Lake 
 Huron and south of Lake Superior. So in Indiana, Illinois, 
 and the north-west generally, we must go northward to find 
 rocks in place which -are of the same sorts as the bowlders. 
 This is plainly demonstrated in the case of bowlders of native 
 copper, which are frequently found in Wisconsin, Illinois, 
 Indiana, Michigan, and Ohio. Therfe is no other credible 
 source than the native copper region south of Lake Superior. 
 So, in the case of the Pierre a bot, near Neufchatel, the 
 nearest credible source is the Mont Blanc chain of Alps, sev- 
 enty miles distant, and separated by the valley of Switzerland 
 and 'the Lake of Geneva. 
 
 We seem authorized to conclude, therefore, that the 
 bowlders have been transported generally from the north; 
 that many of them have been moved one or two hundred 
 miles; that they have sometimes been borne over regions 
 which are now lake-basins; that they have been carried, at 
 times, to higher levels than their origin, and much higher 
 than valleys over which they passed ; that a vast mass of sand, 
 gravel, and clay was moved with them, since they lie imbed- 
 ded in these accumulations, to the depth, sometimes, of one 
 or two hundred feet. 
 
 These conclusions will be borne in mind when we come to 
 seek for the nature of that tremendous agency which could 
 have performed so vast a work over all the northern half of 
 at least two continents. (Talks IV and XL VII.) 
 
 III. THE GRAVEL Frr. 
 
 ARRANGEMENT OF THE DRIFT. 
 
 SHALL we proceed ? This subject has its alphabet, like 
 most others ; and every child can testify that there is little 
 inspiration in the alphabet. A few more letters of our alpha- 
 bet will be found in the arrangement of the loose materials 
 which cover the surface of the northern states. These ma- 
 terials are called Drift. The bowlders are a part of the Drift 
 
THE GEAVEL PIT. 19 
 
 Now we wish to know more about the internal constitution 
 of this deposit. This will be easy, for the Drift is all about 
 us, and numberless deep excavations have been made for sun- 
 dry purposes. Let us visit a gravel pit, or some deep railroad 
 cut through a pile of these incoherent materials. 
 
 Do you find these loose sands and gravels arranged in 
 regular courses ? Yes, you say ; and then you hesitate ; and 
 well you may; for the semblance of courses is exceedingly 
 interrupted. Here is indeed, a layer or bed, or stratum of 
 sand, but it thins out in one direction, and in the other, 
 loses its upper and lower boundaries, and merges in a general 
 mass of sand. Here is a bed of gravel, but it lies at a dif- 
 ferent inclination from the last, and in one direction it changes 
 to sand, while in the other, it becomes split up into a num- 
 ber of subordinate layers which bend down and lose themselves. 
 This bed also is composed of many oblique laminae, coarser 
 and finer in alternation, which are cut off completely by the 
 upper and lower surfaces of the bed or stratum. What is 
 singular, the very next bed below this, which is also obliquely 
 laminated, has its laminae tilted in the opposite direction. 
 And then next to this is a long straight course of cobble- 
 stones and pebbles. Is not this a correct description of what 
 you have all seen somewhere ? 
 
 In some places are large beds of fine sand, which are 
 taken out and used for mortar-making. In others we find 
 extensive deposits of gravel and pebbles, which are used for 
 paths and streets. Mixed in the sands are some cobble-stones 
 and large bowlders. Here and there, too, are some beds con- 
 taining much clay ; and these are impervious to water. Now, 
 all this is not a regular nor a perfect bedding or stratification. 
 We may say the Drift here is semi-stratified. You can all 
 recall some locality where this arrangement of materials 
 occurs. 
 
 This cut or exposure, however, extends only fifteen or 
 twenty feet down. How is the arrangement below? There 
 are places where the bed-rock is not reached in less than a 
 hundred or two hundred feet. There are wells fifty to eighty 
 
20 WALKS AND TALKS. 
 
 feet deep, without reaching bed-rock. Those who have seen 
 such wells have observed the deeper structure of the Drift ; 
 and they report it much like what we see in the gravel-pit. I 
 will tell you how we shall ascertain the arrangement to the 
 depth of perhaps two hundred feet. Go to the lake-shore, or 
 the sea-shore. Of course it must be a place where the shore 
 is not formed of bed-rocks. Here the whole thickness of the 
 Drift may be cut through, exposing at the bottom the solid 
 foundation on which the Drift reposes. Well, here we find 
 two kinds of Drift. The semi-stratified Drift passes down 
 into a sheet of Drift quite unstratified. It consists of blue 
 clay and a large quantity of imbedded bowlders. These are 
 rounded like those at the surface. They are in every respect 
 the same thing made, apparently, by the same agency ; trans- 
 ported in the same company. This is the Bowlder Clay 
 or Till 
 
 We must state, however, that in some situations the semi- 
 stratified Drift rests directly on the bed-rock. Perhaps in 
 these places the Bowlder Clay was washed off before the semi- 
 stratified Drift was laid down. Again, there are many places 
 where the semi-stratified Drift does not rest on the Bowlder 
 Clay perhaps because it was never laid down ; but more 
 probably because it has been removed. In such places the 
 stiff, blue clay is exposed over the surface, and the soil is full 
 of bowlders. Can you not call to mind such a place? 
 
 The sheets of sand and gravel, often obliquely laminated, 
 which we saw in the gravel-pit, were there cut through in a 
 vertical section presented edgewise. You must think of these 
 sheets as extending into the earth a certain distance, but very 
 irregular in extent as well as in form and position. Some 
 of them are flat; some are concave upwards, and some are 
 convex. Now and then one is nearly horizontal, but most are 
 considerably inclined. 
 
 Did you ever see a huge mound of rock-rubbish at the 
 foot of a torrent rushing down a steep ravine to the open, 
 level land a torrent sometimes suddenly swollen to a terrific 
 and maddened volume, which tears stones and trees from their 
 
, THE GRAVEL PIT. 21 
 
 fastenings? And have you ever seen such mound cut through 
 for a highway or other purpose ? If you have, you have wit- 
 nessed a semi-stratified order of deposition somewhat like that 
 in the Drift. Those who have thought on this resemblance 
 have reached the conclusion that the semi-stratified Drift must 
 have been moved and laid down by some kind of torrential 
 action. 
 
 But however this was, the origin of the bed of Bowlder 
 Clay must have been very different. Here is no sort of bed- 
 ding. The whole is in a state of uniform confusion. Evi- 
 dently, then, Nature employed two kinds of action successively 
 in transporting and dispersing the Drift. In the semi-stratified 
 Drift, water in tumultuous movement may have been the 
 chief agent. In the Bowlder Drift water was not the chief 
 agent, since here is none of the assortment and stratification 
 due to water, and here also are rock-masses moved scores or 
 hundreds of miles, and these results are not ascribable to water. 
 
 Let us take another glance over the general distribution of 
 the Drift. We have seen the bowlders increasing in bulk and 
 abundance northward. We have seen the whole Drift forma- 
 tion terminating southward on about the parallel of Cincinnati. 
 We find incoherent surface deposits in Kentucky and southward ; 
 but they contain no bowlders ; and they have mostly resulted 
 from the disintegration and decay of the bed-rocks in place. 
 The Drift, then, is a northern phenomenon. 
 
 If we notice more carefully the detailed distribution of 
 bowlders, we find that, while they have generally moved 
 southward, there has also been a radial distribution from high 
 mountains. In New Hampshire the bowlders move east and 
 west from the White Mountains, as well as south. In Switzer- 
 land, the Pierre a bot and thousands of other bowlders moved 
 north-westward from the Mont Blanc range though on the 
 opposide sides of Mont Blanc the movement was in the op- 
 posite direction. In the Kocky Mountains and the Sierra 
 Nevada, the movement of the bowlders was east and west 
 from the mountain axis. So, too, the southward distribution 
 of bowlders was greatest along mountain elevations. 
 
22 WALKS AND TALKS. 
 
 Thus the distribution of Drift materials sustains a relation 
 to altitude similar to that which it sustains to latitude. What 
 factor, or force, or agency exists in altitude which exists 
 identically in latitude? Temperature, certainly. To ascend 
 a high mountain range is the same as to ascend to a high lati- 
 tude. All high mountains support animals and plants related 
 to species farther north. On the summit of Mount Washing- 
 ton are the butterflies and plants of Labrador. Ascending the 
 Andes, you have tropical products at the foot, temperate pro- 
 ducts at ten thousand feet, and arctic conditions at the sum- 
 mit. The distribution of the Drift, then, has relation to heat 
 and cold. Greater cold has been accompanied by larger re- 
 sults. Bowlders are more numerous and more massive in 
 northern and in elevated regions, because the cold is there 
 more intense. 
 
 Now, how does cold act to effect transportation of rock- 
 fragments? Our thoughts run over the world to scrutinize 
 the modes of action of cold. Much cold implies much snow 
 and ice, if moisture and water are abundant. Most far north- 
 ern regions and high mountain summits are covered much of 
 the year, or the whole of it, by a sheet of snow. Winter 
 snow, under the action of thawing and freezing temperatures 
 in alternation, becomes granular, as we often observe in old 
 snow, especially in early spring. With a more advanced 
 stage of granulation, the icy grains coalesce into larger grains, 
 and finally merge completely into a solid mass of ice. This, 
 also, we have often noticed in the last lingering patches of 
 last winter's snow. 
 
 We have many observations of this kind on a large scale. 
 On high mountains broad fields of granular snow come into 
 existence, and at a certain elevation the average annual tem- 
 perature is not sufficient to dissolve it before autumnal snows 
 begin to increase the amount. The old snow becomes a per- 
 manent granular sheet on the high slopes. In the Alps the 
 Germans designate it Firn, and the French, Neve. When the 
 firn-masses are accumulated in valleys, the amount of snow is 
 so great that it may reach to a much lower altitude before 
 
THE GRAVEL PIT. 23 
 
 finding a temperature which will suffice to melt it all away be- 
 fore the next winter. So tongues of granular snow stretch 
 down the mountain valleys, and being, like our late spring 
 snow, exposed to increased action of warmth, these valley pro- 
 longations of the upper firn become completely changed into 
 solid ice. This is now a glacier. 
 
 We may reason a step further from facts of observation. All 
 substances expand with increase of temperature, and contract 
 with reduction of temperature. The glacier is certainly at a 
 lower temperature in winter than in summer though it can 
 never be warmed above thirty-two degrees Fahrenheit, which 
 is the thawing temperature. The surface of the glacier is also 
 at a lower temperature during the night than during the day. 
 The glacier, therefore, must sometimes expand and some- 
 times contract. Now, when it expands, the whole expansion 
 will be developed at the free lower border, since the upper 
 border is frozen to the earth, and pressed also, by the snows 
 beyond. Also, if both were free, most of the expansion would 
 be developed below, because gravity aids motion downwards. 
 Next, when the glacier contracts, the lower border does not 
 retreat, because the ice is not strong enough to bear the pull 
 of the mass up the slope. The ice breaks in innumerable 
 little cracks. These are soon filled with water, which freezes, 
 and thus restores the complete solidity of the glacier. Thus, 
 when the next expansion takes place, the glacier takes another 
 slide down the valley. So the glacier travels. So, if a whole 
 state should become glacier-covered, the ice-sheet would have 
 a motion from higher to lower, and from colder to warmer. 
 Every thing on its surface would be transported ; every loose 
 object beneath it or in front of it would be pushed forward. 
 
 Now, here are some hints toward an explanation of the 
 method of transportation of our millions of bowlders. If we 
 go to the Alps we find exactly such glaciers, on a small scale, 
 performing precisely such work. Thus our theory receives 
 confirmation. We can not pretend that glacier action ex- 
 plains all the phenomena of the Drift. Nor do we pretend 
 that any thing more than a hint has been given toward an ex- 
 
24 WALKS AND TALKS. 
 
 planation of transportation. The action which arranged the 
 semi-stratified Drift must have been exerted by water rather 
 than ice. But we leave the subject now to your thoughts. 
 You may speculate as much as you please for the purpose of 
 forming a complete theory. You will find such occupation 
 interesting and profitable. By and by we shall come upon 
 this subject again from another direction. (Talk XL VII.) 
 
 IV. AMONO THE GLACIERS. 
 
 GEOLOGICAL ACTION OF GLACIERS. 
 
 PERHAPS it is best to pause at once and contemplate a 
 fuller sketch of some living glaciers. We indulged in a little 
 speculation about the cause of the Drift. We argued that 
 glaciers must perform a work pretty nearly such as the Drift 
 required ; and I cited you to Alpine glaciers as actually exem- 
 plifying this kind of work. But come, now, let us take a 
 closer look at Alpine glaciers. The scenes are abundant in 
 picturesque interest as well as instruction. 
 
 About fifty miles from Geneva lies the * ' vale of Chamo- 
 nix" the classic valley of classic glaciers. Its axis lies 
 nearly east and west, and the Arve, taking its rise from the 
 east, flows through the length of the valley, and bends north 
 to the Lake of Geneva. On the north, the valley is bounded 
 by the sharp pinnacled Aiguilles Rouges (A-ghee-Roosj) ; on 
 the south rises the stupendous mass of the Mont Blanc 
 (Blahnc) range, nearly sixteen thousand feet above sea level. 
 The rounded summit of the monarch mountain is silver white 
 with perpetual snow. On one shoulder rises the Dome du 
 Gouter, and on the other the Aiquille de Gouter (A-ghee-du- 
 Goo-tay). For three thousand feet below the summit, com- 
 pact snow covers the surface to an unknown depth. In one 
 region below the Aiguille de Gouter, may be seen a long per- 
 pendicular cliff of snow left by a slide. It looks like a vast 
 entablature to the glittering dome. This is said to be fifteen 
 hundred feet in height. At the foot of the final dome 
 
AMONG THE GLACIERS. 25 
 
 stretches a fathomless crevasse, in which a number of persons 
 have been lost. This is the "Grande Crevasse," and for a 
 long time it prevented all successful approach to the moun- 
 tain's summit. Sometimes a temporary bridge is stretched 
 across by drifting snow. Occasionally it becomes sufficiently 
 solid to serve for a passage over, but it is always treacherous, 
 and ODce precipitated an English lady and her companion to 
 a depth from which they were never recovered. 
 
 From the Grande Crevasse stretches a gentle slope called 
 the Grand Plateau at an elevation of thirteen thousand feet. 
 This is covered with granular neve. Along its lower limit the 
 snow-mass is broken into tumultuous confusion, and the pas- 
 sage over it is difficult and dangerous. Below this is the 
 Little Plateau, ten thousand feet above sea-level ; and then 
 come other broken belts of snowy precipices. Now, the 
 upper limits of two glaciers are reached in the downward 
 flow of the ice. This common ice-field is a scene of grand 
 confusion. The mountain slope beneath the ice-sheet presents 
 many irregularities of pitch, and many projecting bosses. 
 Over all these the ice-stream flows toward the lower level. In 
 one place, nine thousand feet above sea-level, a vast pinnacled 
 mass of rock rises some hundreds of feet above the ice. This 
 divides the wide stream, but the parts completely coalesce 
 again around the lower side. In other places, the underlying 
 inequalities break the sheet by fractures large and small. 
 Some of these crevasses extend up the general slope, and 
 others are transverse. The ice-mass is therefore broken into 
 innumerable prismatic fragments. The tremendous mashing 
 together which they experience through the movements of 
 the flow, squeeze numbers of them out of their places; and 
 they stand as huge pyramids and columns ten, twenty, and 
 forty feet above the general surface. The columnar forms 
 are called seracs. The afternoon sun acts on them, and some 
 are sharpened to a point ; others are worked out at the sides, 
 and stand with broad flat caps. Finally they tumble down 
 or waste away, while new ones rise in other places. Though 
 the ice is continually shattered by crevassing, the fissures are 
 
 3 
 
26 WALKS AND TALKS. 
 
 continually closing together, when changes in underlying con- 
 figuration permit. Two fractured surfaces pressed tightly 
 unite again as one mass; and a patch shivered into ten thou- 
 sand fragments becomes solid and transparent under the lat- 
 eral squeezing to which it may become subjected. So, to 
 whatever extent the ice-sheet may be shattered, it is continu- 
 ally healing, and tends to return to the condition of a sound 
 and solid mass. Thus the tourist, picking his way among the 
 seracs, and jumping the bottomless chasms, hears frequently 
 the detonation of some new split, which is echoed back from 
 the red pinnacles of Mont Maudit, which rises on his left. 
 These themselves hurl down rocky fragments to keep alive 
 the watchfulness of the traveler, and place material on the 
 back of the glacier to be borne gradually but steadily down 
 toward the valley. 
 
 The common glacier-field just mentioned strikes the sharp 
 upper limit of a mountain salience, which slopes down to the 
 valley of Chamonix, and separates two mountain valleys. 
 This prominent dividing point is the Aiguille de la Tour. As 
 the common ice-mass impinges against it, the ice parts to the 
 right and left like a river. Down the western valley flows 
 the ice-stream known as the Glacier de Taconnay. Down the 
 eastern valley flows the greater stream known as the Glacier 
 des Bossons, having the little village of Bossons at its foot. 
 Another valley lies still farther west, and the common ice- 
 field of Mont Blanc fills it with a stream known as Glacier 
 de la Gria. 
 
 These three glaciers descend to the valley on the west of 
 the pretty village of Chamonix. On the east are three others. 
 The nearest is the celebrated Mer de Glace, the lower part of 
 which is called the Glacier des Bois, with the little village of 
 Bois at its foot. The snowy eastern slope of Mont Blanc and 
 Mont Maudit (Mo-dee) feeds an enormous glacier which, to an 
 observer from the valley of Chamonix, lies behind the pinna- 
 cled summits of Charmoz and Midi. This is the Glacier du 
 Ge"ant, and it forms the western tributary of the Mer de 
 Glace. Into the head of the Mer de Glace comes the Glacier 
 
AMONG THE GLACIEES. 27 
 
 de Lechaud (La-sho), fed by the snow-fields of the Grandes 
 Jorasses. On the east, the Lechaud is reinforced by the 
 broad triangular Glacier de Talefre (Tah-lefr'), in the midst 
 of which, at an elevation of 9,143 feet, is the Jardin, an 
 island of land-surface, walled in on all sides by lofty mount- 
 ains, and adorned in August with a display of several species 
 of Alpine flowers. 
 
 Beyond the Mer de Glace is the Glacier of Argentiere a 
 fine long river of ice, almost equal to the Mer de Glace itself. 
 The bright village of Argentiere lies at its foot. At the very 
 head of the valley of Chamonix comes down from the same 
 direction, the Glacier du Tour. Thus six glaciers descend into 
 the valley, and each contributes its torrent of muddy water 
 to create and swell the Arve. This grand series of ice-rivers 
 and the more majestic mass of the mountains, with their 
 swelling domes and sky-piercing pinnacles, may be contem- 
 plated as a panorama from the .summits which overlook the 
 valley from the north, and put the spectator face to face be- 
 fore the stupendous Mont Blanc range. No person can gaze 
 on this spectacle from the Flegere, which faces the Mer de 
 Glace, or from the Brevent, which faces directly the Glacier 
 des Bossons and Mont Blanc, without feeling a sympathy with 
 Coleridge in his " Hymn in the Vale of Chamonix :" 
 
 " Ye ice-falls ! ye that from the mountain's brow 
 Adown enormous ravines slope amain, 
 Torrents, methinks, that heard a mighty voice, 
 And stopped at once amid their maddened plunge ! 
 Motionless torrents ! silent cataracts ! 
 Who made you glorious as the gates of heaven 
 Beneath the keen full moon ? Who bade the sun 
 Clothe you with rainbow ? Who with living flowers 
 Of loveliest blue spread garlands at your feet ? 
 God ! Let the torrents like a shout of nations 
 Answer, and let the ice-plains echo, God ! " 
 
 The conception of a glacier as a frozen cataract is sugges- 
 tive and truthful. When, from the Montanvert, overlooking 
 the Mer de Glace, De Saussure contemplated the sea of ice, 
 he received an impression thus recorded: "Its surface re- 
 
28 WALKS AND TALKS. 
 
 sembles that of a sea which has become suddenly frozen not 
 during a tempest, but at the instant when the wind has sub- 
 sided, and the waves, although very high, have become 
 blunted and rounded. These great waves are nearly parallel 
 to the length of the glacier, and intersected by transverse 
 crevasses, the interior of which appears blue, while the ice 
 is white on its external surface." Farther down, in the nar- 
 rower Glacier des Bois, the seracs and needles bristle over the 
 surface in mighty uplifts and fearful confusion. 
 
 The crevasses really run in any direction, according to the 
 nature of the underlying surface. In length they vary from 
 twenty feet to a mile. The downward direction is originally 
 vertical, but as the surface of the glacier moves more rapidly 
 than the deeper portions, the transverse crevasse assumes, 
 after a while, an inclination which gives it a dip up the val- 
 ley. Its depth may be ten or a hundred, or two hundred 
 feet ; and its width, which is a few inches at first, may grow 
 to fathoms. Forbes measured a crevasse at the base of the 
 Glacier du Geant, which had a breadth of not less than 1,214 
 feet. The two walls generally approach each other downward, 
 and we may sometimes safely descend to the bottom. The 
 wall-ice is absolutely immaculate, with a greenish blue trans- 
 parency. Down in the crevasse we hear the rills coursing 
 through the substance of the glacier, and sometimes the cen- 
 tral torrent rumbling along the bottom. The surface of the 
 glacier is white and granular, from the action of the sun. 
 Pools of water rest here and there pure, cgol, and refreshing 
 and numerous rills flow over the surface, discharging them- 
 selves through crevasses and perforations in the ice-mass, into 
 some subglacial stream. 
 
 Each of these great glaciers is bordered by a moraine, or 
 long ridge of material thrown off the surface in the course 
 of ages, and pushed up by the movements of the ice. It con- 
 sists of clay and rounded bowlders. It is completely unstrati- 
 fied, and resembles precisely, the till at the bottom of the 
 Drift. These lateral moraines at the present epoch, tower fifty 
 to eighty feet above their glaciers. The ice, for centuries, has 
 
AMONG THE GLACIERS. 29 
 
 been in process of shrinkage. Such masses of debris could 
 never have been raised by the existing glaciers. Other attes- 
 tation of a former higher stage of the glaciers is seen in the 
 smoothed and striated rock-slopes which bound the glacier 
 valleys. These surfaces remind us of the smoothed and 
 striated rocks underneath the till in America. The records 
 of the glaciers may be traced on these smoothed slopes, two 
 or three hundred feet above the present ice-surfaces. 
 
 At the foot of each glacier is a terminal moraine, which 
 is continuous with the two lateral moraines. Among the 
 Chamonix glaciers, this moraine is half a mile or more below 
 the termination of the ice, showing to what extent the glaciers 
 have diminished in length. These remote moraines were left 
 in 1817 and 1826. The " chief of guides" at Chamonix 
 remembers the occasion, and narrated to me a number of 
 memorable incidents. The plain between the moraine and the 
 foot of the glacier is strewn with bowlders. Many descend 
 on the surface of the ice or imbedded in its mass. One sees 
 them frequently precipitated from the foot of the Glacier des 
 Bois to the plain below. The diminution of the glaciers ap- 
 pears to be a persistent phenomenon, and not dependent on 
 climatic fluctuations of short period. There must be either a 
 continuous diminution of cold or of precipitation. 
 
 All parts of the glacier mass move continually downward. 
 In the Glacier des Bossons the amount of the movement has 
 been determined by means of a catastrophe. In 1820, eight 
 persons were buried in the Grande Crevasse at the foot of the 
 dome of Mont Blanc. In 1861, their remains began to ap- 
 pear in the ice near the termination of the glacier. In forty 
 years they had traveled 26,000 to 29,000 feet, or 680 feet a 
 year. As they were buried 200 feet beneath the surface, it 
 appears that 200 feet had been melted from the top of the 
 glacier in the same interval. The Mer de Glace, as shown 
 by Forbes, moves past Montanvert at the rate of 822 feet 
 per annum. Near the foot of the Glacier des Bois the motion 
 is 209 feet a year. The lower Glacier of the Aar, which was 
 the scene of Agassiz's observations, moves downward at an 
 
30 WALKS AND TALKS. 
 
 average rate of 250 feet per annum. Hugi's hut according 
 to Agassiz, had been carried 5,900 feet in thirteen years. A 
 record bottled up by Hugi, stated that it had traveled 197 feet 
 in three years and 2,345 feet in nine years. The great conti- 
 nental glacier would not have traveled at rates so rapid ; but 
 if it moved 20.0 feet a year, the time required to transport a 
 bowlder 250 miles would be 6,600 years. 
 
 These interesting Chamonix glaciers are but the stumps of 
 what they have been. Once they were noble tributaries of a 
 greater glacier which filled the valley of Chamonix. Out 
 of this valley it passed along the valley of the Arve, all the 
 way to Geneva. As we ride along the highway, the rocky 
 bounding walls rise on either hand, smoothed and scored after 
 the same fashion as the rock-walls of the valley of the Mer de 
 Glace. Evidently, the Chamonix glaciers have long been in 
 process of shrinkage. Evidently, they once existed under an 
 enormous development. When that period was passing, we may 
 well believe our northern states were extensively glaciated, 
 and a work was in progress very nearly like that which we 
 have already reasoned out. With these facts before us, we 
 shall be prepared to appreciate the picture of continental 
 glaciation that will be presented as we trace the later history 
 of the world. 
 
 V. THE HiivLsiDK SF>RINO AND ITS \VORK. 
 
 SUBTERRANEAN WATERS AND THEIR DEPOSITS. 
 
 WHERE goes the rain which falls upon the earth ? If the 
 surface were completely level, and all the water should stand 
 which comes from the clouds in the form of rain and snow, 
 it would be everywhere about forty inches deep. In some 
 parts of the United States it would be more, and in others 
 less than this. Such an amount of water would be 34,480 
 barrels on every acre. What becomes of all that water? 
 
 Part of it runs off, you say ; and part of it soaks in the 
 ground. True, and part of it evaporates, and is afterward 
 
THE HILLSIDE SPRING AND ITS WOEK. 31 
 
 condensed and rained down again. Also, part of that which 
 soaks in the ground returns when the surface becomes dry, 
 and is evaporated. But, not to be too precise, let us attempt 
 to follow the water which soaks in. First of all, it must have 
 dissolved some substances with which it came in contact at 
 the surface. These substances must be, to a limited extent 
 certain mineral constituents of the Drift; but the Drift has 
 been so many thousand years exposed to rains, that all its 
 readily soluble constituents have been dissolved away from 
 the surface. The chief agencies which supply soluble matters 
 to the surface are man and animals. The underground waters, 
 therefore, carry with them a certain amount of solutions of 
 organic and inorganic origin, and are not absolutely pure, 
 like carefully distilled water. They may even be poisonous 
 and unsanitary. 
 
 Following these waters in thought, beneath the surface, 
 we see them percolating through the sands and gravels, which 
 we have found to make up the principal part of the tipper 
 Drift. Through layer after layer they continue to descend. 
 If any obstruction is encountered, they are quickly deflected 
 around it, and so continue- to settle toward the impervious 
 Bowlder Clay at the bottom of the Drift; or, if that is 
 absent, the waters settle to the bed-rock. We will not attempt, 
 at present, to follow them in the rocks. 
 
 Now, we know that the Drift contains sheets of impervious 
 clay. Of course, then, these intercept the descending water. 
 The water arrested by a clay-bed saturates the overlying sand, 
 and gradually flows along the surface of the clay to a lower 
 level. But we have seen that all these Drift beds are of 
 quite limited extent. The water, therefore, soon reaches the 
 edge of the clay-bed and escapes down to a lower level. 
 Probably it is again intercepted by a deeper clay-bed. Along 
 this it flows in a similar way, and so continues always ap- 
 proaching nearer and nearer to the lower limit of the Drift. 
 Some of the clay-beds are concave upward, and thus form real 
 dishes or cisterns, which remain full. 
 
 Suppose we dig a well. While passing through the sandy 
 
32 WALKS AND TALKS. 
 
 strata, from which the water drains away, no supply will be 
 struck. As soon, however, as we reach one of the subter- 
 ranean basins or cisterns, a supply is found. Should we dig 
 a hole through the bottom of the cistern, we would, of course, 
 lose much if not all of the water. But we might continue 
 down to the next water-basin. 
 
 Let us suppose another well is needed, a few rods away. 
 We must not be too sanguine in the expectation of getting 
 water at the same depth. Perhaps the new well is beyond 
 the limits of the higher water-basin; we must then dig to 
 some lower one. Perhaps the new well is on higher ground ; 
 it does not follow that we must dig to the level of the basin 
 in the first well. In the higher ground may be a higher 
 water-basin ; and so the second well, though several feet higher 
 than the first, may not require to be so deep. 
 
 Do not suppose these water-beds are everywhere of such 
 limited extent. There are districts where the same bed may 
 be traced one or two miles. The bed, in such cases, is 
 nearly horizontal; and that condition of the underground 
 structure is indicated by a level condition of the surface. 
 
 Now, how are springs produc.ed? Suppose a river valley 
 has cut through a deep mass of the Drift, must it not cut 
 the water-bearing sheets with the rest? And when that is 
 done, will not the water flow out? Certainly, just as when 
 we knock a hole in a cistern. So a hill-side spring is noth- 
 ing but a leak in one of nature's cisterns. The water in es- 
 caping from the cut edge of the sheet finds some spot where least 
 resistance is experienced, and there it escapes in largest quan- 
 tity. It forms a sort of stream, and by degrees wears a little 
 channel, which extends back into the bank, opening at its 
 mouth in a little arch under which the water finally escapes. 
 Of course, all the work was accomplished before we ever saw 
 the spring. A well is an artificial spring. 
 
 Generally, the water of a hill-side spring is allowed to flow 
 off to a brook or rivulet. In the course of a number of miles, 
 scores or hundreds of springs may discharge their contributions 
 into the stream. In fact, the greater part of the water in the 
 
THE HILLSIDE SPRING AND ITS WORK. 33 
 
 stream is supplied by springs. It gets directly from rains 
 only so much as flows from the surface of the basin which 
 the river drains. Most of the rain falling within the basin, 
 however, sinks into the ground, and finds its way into the 
 stream only in the form of spring water. But when a stream 
 flows over a drift-formed bed, much water wastes away. Be- 
 sides this, many deep water-basins convey their contents under 
 the river. So the river never contains the whole amount of 
 water which falls within the basin which it drains. 
 
 Suppose all the water-basins under a township or a county 
 should cease to exist, what would become of wells and springs ? 
 You understand at once that they would dry up. Therefore 
 the streams would dry up. The water would settle to the 
 Bowlder Clay or the bed-rock, and there would be the only 
 accumulation. Every well must then be sunk to that depth 
 even if it were two hundred feet. And wells would be the 
 only resort, for of springs there would be none ; of brooks 
 there would be none; of ponds and lakelets there would be 
 none. Then, again, the Drift sands being so dry, little evap- 
 oration would take place from the earth's surface. The air 
 would be dry ; no dew would condense ; no clouds would 
 form, and so the rains would stop descending, unless some 
 other region could supply us with clouds. How beneficent, 
 then, are the clay-beds ! Literally, they are all which saves 
 many a fertile region from becoming a desert and an unin- 
 habitable waste. We looked carelessly at these courses of 
 sands and clays exposed in the railroad cut, and thought, per- 
 haps, they only served to form a pile of earth for the rail- 
 road builder to cart into the neighboring filling. How 
 admirably the constitution of the Drift is suited to human wants ! 
 To us it looks as if it had been an intentional preparation for 
 man. There are persons, however, who prefer to say it is not 
 so ; but man is here only because the situation is one which 
 permits him to be here. But we are sure, at least, that a 
 happy coordination exists between our necessities and our sur- 
 roundings ; and the constitution of things which brings enjoy- 
 ment out of the coordination is a beneficient constitution. . 
 
34 WALKS AND TALKS. 
 
 In regions of deep Drift and abundant water-basins, the 
 supplies of spring-water are sometimes sufficient to meet the 
 demands of towns and cities. The city of Ann Arbor, with 
 its ten thousand of population, is thus supplied with nearly 
 five hundred thousand gallons daily. This is obtained from 
 two groups of springs, and distributed through the city in the 
 usual way. Five times this amount could be had, if needed. 
 
 Now let us consider springs in another light. We have al- 
 ready reflected that the percolating water takes some substances 
 in solution from the surface. It must take up much more in 
 leaching through the sands. This is the reason why most 
 sands are composed chiefly of insoluble constituents. Their 
 soluble constituents have been leached out. But there re- 
 main still, in many regions, some soluble limestone pebbles or 
 larger masses which have not yet been dissolved, and the 
 water is continually diminishing the amount of these. * Now, 
 first of all, consider that this little fact is a demonstration 
 that the present order of things has not existed from eternity. 
 If it had, all the soluble substances would have disappeared 
 long ago in fact, an eternity since. The time, therefore, 
 since this Drift was brought here is only a finite number of 
 years. That is a positive datum. 
 
 Water that has dissolved much limestone is "hard." Hence, 
 many spring and river waters are hard. The water of a pond 
 may be softer, because a large proportion of it has been di- 
 rectly rained in, or supplied by surface drainage from the sur- 
 rounding land. Of course, the hardness of underground water 
 depends upon the amount of limestone pebbles and grains 
 with which it has come in contact. Aside from any supply 
 of limestone from neighboring ledges, the amount of limestone 
 in the Drift depends on the amount transported from the north- 
 ern regions which supplied the material of the Drift at each 
 particular place. Some northern regions supplied much lime- 
 stone, and others little. Hence, in Michigan, Ohio, and In- 
 diana, well and spring waters are hard, while in New England 
 and Pennsylvania they are comparatively soft. 
 
 Under-ground water often experiences great pressure. In 
 
ISTTKODUCTION TO THE ROCKS. 35 
 
 this state it dissolves more limestone than it can hold in solu- 
 tion after the pressure is relieved. Hence many springs throw 
 down a calcareous deposit which in the open air hardens into 
 tufa and travertine. It often incrusts mosses and forms what is 
 called "petrified moss." The vegetable matter perishes and 
 disappears by degrees, but the form of the moss remains. 
 Calcareous springs flowing into ponds cause a deposit of chalky 
 matter on the bottom, which is called marl. It is generally 
 mixed with earthy substances washed in from the surround- 
 ing slopes. 
 
 In precisely the same way certain springs deposit peroxide 
 of iron, which is yellowish or red. Iron is also often trans- 
 ported to bogs and ponds, and there undergoes deposition. 
 Thus bog iron ore is formed. 
 
 Now, I wish to ask Johnnie if he understands what has 
 been said in this Talk. I hope he will think these matters 
 over. They will help him to understand, by and by, some 
 matters which are far more interesting. At least, I think he 
 will find them so. 
 
 VI. INTRODUCTION TO THE ROCKS 
 
 KINDS OF MINERALS AND STONES. 
 
 IT is not entirely satisfactory to roam over the fields, with 
 bowlders lying on the right and left, but without any knowl- 
 edge of their names or natures. True, we shall experience 
 much satisfaction in feeling that we know something of their 
 origin and their history. We may walk up to the side of one 
 of these ancient and way-worn travelers and say: " Old Hard 
 Head, when did you arrive in this country, and where did you 
 emigrate from ?" Old Hard Head will lie sullenly and answer 
 never a word. But he is written all over with inscriptions 
 which we can already begin to decipher. So we look on the 
 rounded and weather-beaten form, and say to ourselves: 
 " This immigrant rock came from a northern country. He 
 
36 WALKS AND TALKS. 
 
 left his mother-rock, and most of his kindred, in the woods of 
 northern Maine, or New Hampshire, or on the shore of Lake 
 Superior. A large number of his kindred came with him. 
 He rode part of the way on the back of a glacier. By and 
 by he fell off, or got into a hole ; and after that he had a severe 
 squeezing. He got crushed and rubbed and rolled and pushed 
 for some thousands of years. But every year he made some 
 progress. By and by there was a great change of weather. 
 The ice-carriage melted away from him, and fine weather re- 
 turned, and lo! he found himself, one spring, in this field. 
 That was long enough before Adam and Eve set up business 
 in gardening. But here old Hard Head has been lying ever 
 since. And now, we are the very first persons who ever 
 stopped to pay him a moment's attention, and make his 
 acquaintance." 
 
 If old Hard Head thinks, he is revolving some handsome 
 compliments on our intelligence. Whatever old Hard Head 
 may think, we are sure the ability to learn something of the 
 method of the world was given us to be exercised. If we go 
 stupidly through the world, without exercising that ability, we 
 do no better than an ox. But if we seek to gain an insight 
 into the method and history of the world, we honor the Author 
 of the world ; we read His thoughts. Knowing some of His 
 thoughts, we come into more intimate relations with 
 him. The study of science is a virtue. Attention to 
 geology is a human duty. 
 
 To complete our introduction to old Hard Head we must 
 know his name. To call him old Hard Head is like calling a 
 man " Old Russian" or " Old Englishman." He has, besides, 
 his personal name. Now, there is a way of finding out the 
 particular name of each rock. Like a dog with his 
 name on his collar, each mute rock displays a name writ- 
 ten on its exterior. Let us look into this subject a few 
 minutes. 
 
 Do you see that nearly all these bowlders appear to be 
 mixtures of different colors and kinds of rocks? See one 
 rock with round pebbles white, red, black imbedded in a 
 
INTRODUCTION TO THE ROCKS. 37 
 
 mass of smaller grains. See another rock, less coarse, with 
 grains white, pink, and black. See still another with grains 
 all nearly alike. See one rock nearly a uniform white ; 
 another, bluish ; another, reddish ; another, nearly black. See 
 one rock with numerous black shining scales; another, with 
 smoky scales; another, with silvery scales. Now, all these 
 differently colored constituents of the rocks are so many differ- 
 ent minerals. Rocks are composed of minerals. Some rocks 
 have two minerals ; some, three ; some, four ; and some, only 
 one. The particular name of a rock depends on the min- 
 erals in it. As soon as we know the minerals, we can call 
 the name of the rock. Now, sit down and take a lesson in 
 minerals. 
 
 Do you see this white flint rock, composed throughout of 
 one kind of mineral ? That mineral is Quartz. It is the hard- 
 est of all the common minerals. Try to scratch it. You see 
 the point of steel makes no impression on it. Rut it leaves a 
 black mark. The Quartz wears away the steel. When one 
 of these bowlders is thus composed entirely of Quartz, its 
 name is Quartzite. There are many Quartzites, as there are 
 many Smiths and Joneses. Let us learn the other part of the 
 name. Look at these uniformly colored quartzites white and 
 gray. You see one is composed of distinct grains; this is a 
 Granular Quartzite. One has the grains almost completely 
 melted together or confluent ; this is a Vitreous Quartzite. One 
 contains pebbles ; this is a Conglomeritic Quartzite, or simply a 
 Conglomerate. Another has some of its pebbles red ; this is a 
 Jaspery Conglomerate. You will find quartzites exceedingly 
 abundant ; and you will find grains of quartz in many other 
 rocks than quartzites. In fact, quartz is most abundant of 
 all minerals. 
 
 Conglomerates always excite curiosity especially if the 
 pebbles are of different bright colors. Two large masses of 
 conglomerates of different sorts lie on the campus of the Uni- 
 versity of Michigan souvenirs of two graduating classes. 
 One is a jaspery conglomerate from the north shore o Lake 
 Huron. It weighs six tons. The plum pudding, as big as 
 
38 WALKS AND TALKS. 
 
 the State House dome, demolished by the giant's wife and 
 her screaming boys, refers to a conglomerate. 
 
 " They flung it over to Roxbury hills, 
 
 They flung it over the plain ; 
 And all over Milton and Dorchester, too, 
 Great lumps of pudding the giants threw ; 
 
 They tumbled as thick as rain." 
 
 Well, here is a rock with shining scale-like mineral frag- 
 ments. Pick up a scale with your knife-blade. Do you see 
 it split into laminse or leaves of indefinite thinness? "Yes," 
 you say; "this is the same thing as is used in the doors of 
 our stoves to permit the light to shine through ; only these are 
 black leaves and those are transparent." Quite right. What 
 do you call the mineral in your stove door? "Mica, though 
 some people call it isinglass." Mica is correct. One species 
 of mica is black, and has a particular name ; another varies 
 from dark-brown or smoky to transparent, and has a different 
 name. There are also some other species of mica. So you 
 know mica. 
 
 Examine this rock very closely do you find any quartz? 
 "Yes," you say, "there are two kinds of light-colored min- 
 erals here." Carefully test them both for hardness. Can you 
 scratch them? " Well, no. One of them is hard enough for 
 quartz it is quartz ; but the other I am uncertain about." 
 Then you must try again. Bear on hard ; can 't you make a 
 little scratch with your knife-point, or the end of a file? "I 
 believe I do make a little impression on it." Well, then, it is 
 not quartz. Now take another look at it. Compare it with 
 the quartz grain by its side. Is its surface broken and irreg- 
 ular? "No," you say, "it is flat." Hold it then so as to 
 reflect the light from the window. Is the reflection as bright 
 and glassy as the reflection from the quartz ? "I think there 
 is a little difference." You see, too, it is an unbroken re- 
 flection, while that from the quartz is not uniform, in conse- 
 quence of the uneven surface. There is also another point; 
 this mineral appears to be a fragment of a crystal ; you can de- 
 tect one or more edges or angles. It is not so with the quartz. 
 
INTKODUCTION TO THE KOCKS. 39 
 
 Thus, in several particulars, this mineral differs from quartz. 
 Its name is Feldspar. But feldspar is not always white nor 
 cream-colored. Very often it is pink-tinted ; often almost red. 
 But you may know it to be feldspar by the same signs, inde- 
 pendently of color. 
 
 So we find in this bowlder three different minerals, and 
 their names are Quartz, Mica, and Feldspar. These three min- 
 erals mixed together form the rock Granite. There are sev- 
 eral varieties of granite, according to the species of mica ; 
 according to the colors of the quartz and feldspar; according 
 to coarseness of the constituents; according to the relative 
 proportions of the three ingredients. But they are all gran- 
 ites. If, however, the minerals are not uniformly mixed ; if 
 they are ranged in courses, the rock is stratified, and it is not 
 a proper granite, though quarry men and builders often call it 
 granite. Properly, it is Gneiss (Nice). If the mica is al- 
 most or completely wanting in a granite-like rock, the rock is 
 Granulite. When a gneiss-like rock contains very little feld- 
 spar, it is Mica Schist (Shist). 
 
 Now, let us examine another bowlder, with a similar ap- 
 pearance, but in which the dark mineral is not mica. Be 
 sure, first of all, that we have quartz and feldspar in it. Then, 
 if the dark mineral is not scaly, it is probably Hornblende. 
 It may be nearly black, or greenish-black, or dark green. It 
 may be in grains, or in flat-sided fragments showing an indistinct 
 fibrous structure. It can be scratched, giving a pale bluish-green 
 streak. Now, a rock with these constituent minerals Quartz, 
 Feldspar, and Hornblende, is Syenite so called because the rock 
 quarried by the ancient Egyptians at Sye'ne was of this kind. 
 Many persons call this granite also. The "Quincy granite," near 
 Boston, is a syenite. Often syenite contains also some mica. This 
 is the case with the "obelisk," in Central Park, New York, 
 and the Mormon Temple, in Salt Lake City. If the constit- 
 uent minerals tend to arrangement in courses, the rock is 
 stratified, and we call it Syenitic Gneiss. If the quartz is want- 
 ing, or nearly so, the rock is Hyposyenite when the feldspar is 
 of the common kind, and Diorite when otherwise. When 
 
40 WALKS AND TALKS. 
 
 Syenitic Gneiss contains very little feldspar, we call the rock 
 Hornblende Schist. 
 
 The names above explained embrace a majority of the 
 rocks, and I do noj; by any means expect you to learn at 
 present all of the others. But we may mention a few. Some 
 rocks appear to be composed wholly of one mineral, and 
 yet they are not quartzites. They are mostly dark-col- 
 ored slate-colored or blackish or greenish. If these are 
 banded in different colors, or are capable of splitting into 
 sheets, like shingles, they are Argillites including most of the 
 hard slates, like roofing slate. If a rock is very fine, black- 
 ish, and harder than slate, it may be an Aphanite. If it con- 
 sists of a very fine, hard, uniform reddish or greenish base, 
 having crystals of feldspar scattered through it, the rock is a 
 Porphyry. But, if you feel inclined to go further into rock- 
 details, it will be better to study some work which takes up 
 the subject more thoroughly. (See the Author's Geological 
 Excursions, and still fuller Geological Studies). 
 
 One word more. These bowlder rocks are all hard, crys- 
 talline, and generally (not always) foreign to the region where 
 they lie. We sometimes find fragments of rocks which are 
 not hard and crystalline, and far-fetched. They come from 
 ledges which appear at the surface not far away. The most 
 common uncrystalline ledges are of sandstone, limestone, and 
 shale. Sandstone is composed chiefly of grains of quartz like 
 those in a granular quartzite, but not so brilliant or so firmly 
 compacted together. A grindstone is a fine sandstone. Lime- 
 stone can be easily scratched with a knife ; is generally not com- 
 posed of grains ; and, if you apply strong acid, an effervescence 
 takes place. Very strong vinegar will often suffice, especially 
 if the rock is first pulverized. Shale is quite soft, easily 
 cut with a knife, dark-bluish or black, splitting into thin 
 sheets. It is exceedingly common in coal regions. It crum- 
 bles into small fragments, and finally becomes mere mud. 
 
 I think this little knowledge about rocks is better than 
 total ignorance. We may now go amongst our bowlders, and 
 speak many of their names. 
 
THE FLOODS OF THE GKEAT LAKES. 41 
 
 VII. THK KLOODS OK THK GRKAT 
 
 LACUSTRINE DEPOSITS AND TEEBACES. 
 
 PERSONS liviDg along -the borders of the "Great Lakes" 
 well understand what is meant by "The Kidge Road." 
 That road is a geological phenomenon. It is a record of high 
 waters in the lakes. It possesses much significance, and opens 
 an interesting vista through a chapter in the world's history. 
 
 The Ridge Road runs parallel with the lake shore for many 
 miles at a stretch. It is almost perfectly level and serves as a 
 ready made road-bed for country roads. It consists of gravel 
 and sands, and presents oblique lamination or cross-bedding in 
 its internal structure. The materials have evidently been ar- 
 ranged by water. It has the general characters of a beach, 
 and like a beach retains a level nearly uniform. Generally 
 two or more of these ancient beaches run parallel with the 
 lake, at different altitudes. The "ridge-road" south of Lake 
 Ontario is 190 feet above the lake. The principal terrace 
 bordering Lake Erie is 220 feet above the lake on the south 
 side. On the north side, near Toronto, there are terraces from 
 30 to 500 feet above the lake. The Davenport ridge west of 
 Toronto is 250 to 300 feet. At the west of Lake Ontario, 
 near Dundas, the ridge is 318 feet high. Around Lake 
 Huron are clayey deposits up to 500 feet. North of Lake 
 Superior the upper terrace reported is 331 feet above 
 the Lake. 
 
 There are other indications that the Great Lakes have 
 formerly stood much higher than at present. Mackinac Island 
 is a monument commemorating in stone the fact of the ancient 
 high tides of the lakes. Get into a Mackinac boat and sail 
 around the island. On all sides a wall of limestone rises per- 
 pendicularly from the water's edge to a height of about 150 
 feet. Only on the south, for a narrow space, is the approach 
 practicable. Here is the village ; back of it, on the first rock- 
 terrace, is the modern fort. The old Fort Holmes, captured 
 by the British, is on the highest dome of the island, 350 feet 
 
 4 
 
42 WALKS AND TALKS. 
 
 above the lake. As we pass along the limestone wall which 
 bounds the island, we see the waves breaking against the bar- 
 rier. We notice the peculiar smooth concavities into which 
 they wore the exposed surface. These are marks character- 
 istic of wave action. Our eyes follow along the weathered 
 buttresses to the summit. From bottom to top are the same 
 records of warring waves. There was evidently a time when 
 the lake acted at the height of 150 feet precisely as it acts 
 to-day at the lake-level, before our eyes. We ascend to the 
 main plateau of the island. On this rises a striking monu- 
 ment-like remnant of a formation which once covered the 
 whole of this plateau to an altitude at least 134 feet greater. 
 This is " Sugar Loaf." But notice the fashion of its sides. 
 Here, too, are the same smooth conchoidal depressions as the 
 lake is still carving in the wall at the water's edge. The waves 
 have certainly been there. The time was when Lakes Huron 
 and "Michigan stood at least 200 feet higher than at present. 
 Think of that condition of things. Picture the lakes filled 
 up till the water covered Sugar Loaf. At present, Lake Su- 
 perior stands twenty feet higher than Lakes Michigan and 
 Huron. These are sixteen feet higher than Lake Erie ; and 
 the descent thence to Lake Ontario is 323 feet. This is accord- 
 ing to Gannett. Now, we find lake-terraces up to three, four 
 and five hundred feet above the present levels of the lakes. 
 But let us assume the principal terrace south of Lake Erie 
 as representing the highest flood of the lakes. This 220 feet 
 above Lake Erie, 204 feet above Lakes Huron and Michigan, 
 and 180 feet higher than Lake Superior. We have perfectly 
 satisfactory proof that the water of the Great Lakes has stood 
 at least as high as this. Now let us cast our eyes over the 
 expanse. The sites of all the busy and populous lake cities 
 are submerged. The greater part of the peninsula of Ontario 
 is under water. The flood stretches westward of Detroit 
 twenty -seven miles. There, near Ypsilanti is the ancient beach 
 which marks the limit of the flood. Mackinac Island is sub- 
 merged to the pinnacle of Sugar Loaf. Passing around to 
 the head of Lake Michigan, we find the vast inland sea 
 
THE FLOODS OF THE GREAT LAKES. 43 
 
 stretching southward and westward over a large part of the 
 state of Illinois. 
 
 What hemmed in this broad expanse of water on the 
 south ? This interesting question has not been completely 
 answered. We know that in southern Illinois are the remains 
 of an ancient barrier which crossed the Mississippi, and was 
 worn down for the passage of the great river. The barrier is 
 a prolongation of the Ozark range, from Missouri. The gap 
 cut through is at Grand Tower. Perhaps here was the bar- 
 rier which held the waters back at the west, until the Missis- 
 sippi gradually sawed the notch which drained the inland sea. 
 At the east, however, we know no barrier adequate to hold 
 the lakes at the level of the 220 feet terrace of Lake Erie. 
 The high flood of the lakes must have been 182 feet higher 
 than the escarpment or wall of rock back of Lewiston, through 
 which the Niagara river has cut its gorge. Undoubtedly, this 
 escarpment, which runs east nearly parallel with the shore of 
 Lake Ontario, was formerly much higher than at present ; but 
 we have no evidence that it stood 190 feet higher than in 
 our time. 
 
 The Lewiston escarpment is at present 38 feet above Lake 
 Erie, and could have dammed the lake to that height, at any 
 time before the Niagara gorge was begun. The water, setting 
 back to the site of Chicago, would have buried it 22 feet 
 deep. Even this would overflow the present southern barrier 
 of Lake Michigan, and inundate the prairie region of Illinois. 
 Thus, the existence of a terrace, but 38 feet above Lake Erie 
 would indicate that the great lakes once flooded the greater 
 part of the state of Illinois. Now, if we examine the nature 
 of the prairie deposit, it presents every indication of forma- 
 tion in the bottom of a lake. Here is the stratified arrange- 
 ment ; here are the clay and marls, and here are even the 
 shells of the molluscs which dwelt in the water. These facts 
 must be borne in mind. 
 
 The high water of the Great Lakes has occurred since the 
 Drift was deposited since the latest semi-stratified Drift was 
 laid down. The lake terraces rest on the Drift. All the 
 
44 WALKS AHD TALKS. 
 
 other lacustrine deposits attending the high water, rest on the 
 Drift. The entire broad region covered by the high water is 
 overspread by a sheet of lacustrine clays and thin seams of 
 sand. These deposits exhibit a regular horizontal stratifica- 
 tion. Occasionally we find a bowlder imbedded in them. 
 Excellent material for bricks and pottery is furnished by the 
 clays ; and in many situations, as at Milwaukee, the absence 
 of iron prevents the production of a red color in burning. 
 The famous "Milwaukee bricks" are of a pale lemon color, 
 or even, in some cases, as white as chalk. This sort of clay 
 occurs on both sides of Lake Michigan. 
 
 These lacustrine deposits rise from the shore with the gen- 
 eral slope of the earth's surface, to the upper level reached by 
 them. The lowest beds come to the surface at the highest 
 elevation. Often these are sandy; and, becoming saturated 
 with rain at the surface, they convey a sheet of fresh water 
 under the other deposits to the lower levels. These water- 
 bearing sheets pass under the cities which have been built in 
 modern times on the lacustrine border. In some cases, as at 
 Toledo, and many points on the north shore of Lake Erie, 
 artesian borings have been carried down to the water-bearing 
 strata, and thus artesian wells have been obtained. 
 
 We have been considering lake-terraces and high water in 
 the Great Lakes. But every observer has noticed terraces 
 also along the borders of rivers. On the lower Ohio they 
 occur up to 160 feet above low water ; at Louisville, 128 feet 
 above low water; near Cincinnati, 120 feet. On the Con- 
 necticut, they range from 150 to 240 feet above the modern 
 flood level. On the Missouri we find them up to 335 feet ; 
 on the Athabasca and Saskatchewan, up to 370 feet. There 
 is no need of citing further ; for these facts show that the 
 rivers in all the northern parts of the country have been 
 enormously flooded, as well as the lakes. These terraces, also, 
 rest on the top of the Drift deposits. The flooded waters, 
 therefore, in general, existed after the events which left the 
 Drift overspreading the northern states. 
 
 Now let us reason a moment from the facts which have 
 
THE MUD FLAT. 45 
 
 been brought to our notice. In our Second and Third Talks 
 we have been led to speculate on the possible agency which 
 transported the bowlders from their northern home. We 
 have been thinking of glaciers as a satisfactory explanation ; 
 and this view was adopted by the late Louis Agassiz, and most 
 ably defended by him. Now, suppose there really, was a vast 
 glacier covering the country as widely as the Drift at present 
 covers it. The ice must have melted; it is not here now. 
 Suppose it melted rapidly ; what enormous floods must have 
 been occasioned ! With what fury those floods rushed over the 
 country to the lower levels ! How they moved and mixed and 
 half assorted the sands and pebbles ! May not such a flood 
 have produced the results which we see in the semi-stratified 
 Drift? And then may not an excess of water have remained 
 in all the streams long after the southern portion of the 
 glacier had disappeared, and the semi-stratified Drift had been 
 put in place? Would not such a state of weather as accom- 
 plished the melting of the ice have been somewhat like our 
 March and April weather, characterized by abundant rains? 
 Do we not find here good grounds for the building of a 
 theory of transported bowlders, half assorted sands and 
 flooded rivers? 
 
 VIII. THE MUD 
 
 SEDIMENTATION. 
 
 WHEN the road-side pool left by the last shower dries 
 away a film of fine sediment remains. This once hung in 
 suspension in the water; it was gathered up from the land 
 by the eddies born of rain. We shall see that this simple 
 observation is the key to an explanation of many of the grand- 
 est facts in the world's history. 
 
 A few years ago, in ascending the valley of the Aar, in 
 Switzerland, I enjoyed an extraordinary opportunity to ob- 
 serve the action of moving water. The Aar is a turbulent 
 stream issuing from the foot of the Aar glacier of the Jura 
 
46 WALKS AND TALKS. 
 
 Mountains. It comes out of its ice-roofed cavern milky white 
 with the clay sediment which results from the scouring of the 
 rocks by the sliding glacier. The sharp collision of trans- 
 ported rock-fragments accompanies the loud roaring of the 
 impetuous stream. On this occasion, the white streamlet, 
 always rapid, had been swollen to a furious torrent by a re- 
 cent cloud-burst. The torrent, in its rage, had rent all bar- 
 riers, and coursed over the adjacent lands. Stones, up to 
 several tons in weight, had been hurled right and left, as the 
 autumn wind disperses the light leaves of the maples along 
 the street. Hundreds of acres lay buried beneath sand and 
 mud, cobble-stones and massive rocks. The rough and rocky 
 slope had received its deposits ; the late goat pasture lay con- 
 cealed beneath a bed of stones, and the grassy flat was hidden 
 by a blanket of gravel and slime. 
 
 Observe the power of assortment exerted by the moving 
 water. The heavier rocks were left where the most precipitous 
 hill-side graduated into the sharp slope. Here was the first 
 abatement of the force of the stream. It dropped what could 
 no longer be moved by the diminished power of the torrent. 
 The smaller rocks lay next in order. Where the sharp slope 
 passed into a gentler grade, the still waning force of the 
 maddened stream became insufficient to bear them on. Still 
 beyond, on the lower levels, the flood was widened, its veloc- 
 ity slackened, and its'transportative power so abated that the 
 average sized cobble-stones had to be left. Still went on the 
 gravel, and found pause only on the pastures where domestic 
 animals had been grazing. But the sand was borne to the 
 level, and spread itself out over many an arable field and 
 fragrant meadow; while the fine alluvial mud had floated with 
 the tired waters, which sought out sheltered nooks and de- 
 pressions in which to rest. 
 
 This was yesterday. This morning the lesson lay before 
 me. Here were effects of a geological cause on whose action 
 the startled peasant yesterday gazed despairingly. He needs 
 no theory to convince him of the nature and mode of action 
 of the forces which devastated his fields; and I, who found 
 
THE MUD FLAT. 47 
 
 in Switzerland many windrows of gathered cobble-stones and 
 pebbles, and sheets of assorted sands and mud, miles in ex- 
 tent, felt that it was scarcely a theoretical view to attribute 
 these larger results of the same kind to a geologic agency of 
 a similar nature, though it had acted unknown ages before 
 human eyes had been created. 
 
 Not far from the home of my boyhood was the mill-pond, 
 dear to every school-ward trudging urchin who had to pass it, 
 and a Saturday resort for many others who lived in the ad- 
 joining " district." Here we bathed ; here we fished ; here we 
 risked our lives in shaky skiffs, and astride of unmanageable 
 logs. The water was deep and clear. Last summer I visited 
 the old pond. Like the anxious parents, who shared with 
 mill-pond the affection of which boyish hearts are susceptible, 
 the scene of so much truant enjoyment was changed almost 
 beyond recognition. The deep, clear water was silted up, and 
 flags were thrusting their brown noses up, in the sites where 
 I used to swim in summer and skate in winter. Sedges 
 fringed the borders ; bulrushes, to their knees in water, were 
 holding possession of land that was expected to be, and the 
 encroaching marsh threatened to corner the anxious perches 
 and sunfishes in the last lingering bowl of clear water close by 
 the decrepit old dam. This, I thought, is a picture of the 
 history of the world. How long, I queried, before this mill- 
 pond will be a swamp ? Is this the impending fate of all our 
 ponds and lakelets ? Johnny, do you think your favorite 
 skating place will over come to this? 
 
 The first land-surveyors of the territory of Michigan laid 
 down on their plats an extraordinary number of swamps and 
 bogs. It is true they greatly overdid the swamp-land business ; 
 but swamps are there in plentiful abundance ; and swamps 
 properly drained and tilled are the richest lands in the state. 
 But the early settlers of Michigan found many of the swamps 
 non-existent; some were grassy plains; some were quaking 
 bogs, and others were part marsh and part lakelet. During 
 sixty years, many of the quaking bogs have become solid 
 meadows; and many of the marsh-side lakelets have totally 
 
48 WALKS AND TALKS. 
 
 disappeared, under the encroachments of the growing marsh. 
 These are geological changes, and the geologist's eye looks 
 about for the causes. It is not a far-fetched solution to see in 
 the hillside wash a source of silt, which annually diminishes 
 the depth of water to a certain extent. And it requires but 
 ordinary sagacity to notice each decaying crop of grasses, 
 sedges, and rushes as the source of the dark peaty deposit 
 which displaces the last water, when other causes have pro- 
 duced the requisite shallowness. We have caught the marsh- 
 making business in the midst of its accomplishment. Short 
 as our lives are, each life falls within the geologic age in which 
 vast results are actually working out. All these marshes have 
 been lakes. If we dig in them we find the bleached relics of 
 the very shells which held animated tenants of the vanished 
 lakelet. Thus, gathering sediments add sheet after sheet to 
 the deposits which are filling the larger as well as the smaller 
 bodies of water which rest on the earth's surface. 
 
 All great rivers are enormous mud-carriers. The Nile, the 
 Amazons, the Ganges, the Hoang Ho, the Mississippi, are 
 great vehicles for the transport of earthy substances from the 
 higher to the lower levels. Like the Tiber, their waters are 
 all "yellow." The Chinese have surpassed all other nations 
 in making a proper name of the generic description of muddy 
 rivers. What a potion is a glass of Mississippi water, placed 
 by the side of one's plate in the cabin of the steamer! In 
 thirty minutes it holds a deposit of impalpable sediment, which 
 is simply mud. Think of the entire breadth and depth of 
 this mighty stream charged with earthy materials to such an 
 extent. What must be the total amount of matter carried 
 down to the Gulf annually? The engineers of the United 
 States have attempted to answer this question. They say that 
 if the annual discharge of mud were brought together and 
 dried, it would form a block a mile square and two hundred 
 and seventy-eight feet high. Imagine that block lying on the 
 surface of some level township. Then think another block 
 on the top the result of another year's transport. Recall the 
 fact that the Mississippi has been at this business at least five 
 
THE MUD FLAT. 49 
 
 or six thousand years. Put five or six thousand such blocks 
 together ; the aggregate would be a mountain range. 
 
 There are seasons when the proud river climbs over its 
 bounds climbs over the artificial restraints which have been 
 imposed in the form of levees. Water and mud spread over 
 hundreds of plantations. Then, as in the overflowing torrent 
 of the Aar, the slackened motion of the water allows the fine 
 sediment to subside. Corn lands and cotton lands receive a 
 new contribution of fertilizing material. Such service the 
 Nile performs for Egyptian agriculture under the rule of the 
 Khedives, as during the reigns of the Pharaohs. Thus the 
 deltas of the great rivers are formed. Still the great prepon- 
 derance of river silt passes on to the outlets. Not only the 
 floating sediment, but a large amount of bottom mud, too 
 thick to float and too loose to lie unmoved. This the stream 
 pushes along into the sea year by year into deeper and deeper 
 water, as the shallower shore region becomes silted up. This 
 is the bar. By the annual extension of the bar, the delta 
 gradually protrudes a tongue of land into the sea. Look at 
 a map of the mouth of the Mississippi, or the Nile, or the 
 Ganges. Often the piled up bar-material so obstructs the exit 
 through the main channel, that the water sets back up the 
 stream during some flood, overflows its'banks, and seeks a new 
 route to the sea. This may be many times repeated. So 
 these great rivers acquire numerous outlets. Look at the 
 map again. The bar at the mouth of the Mississippi extends 
 three hundred and thirty-eight feet into the Gulf annually. 
 
 Much of the Mississippi sediment, therefore, lies somewhat 
 permanently on the Gulf bottom, near the shore. Through 
 this Engineer Eads has staked out a channel, to which the 
 current of the Mississippi is confined after entering the Gulf, 
 until deep water is reached. Its velocity is thus preserved, 
 and its mud is carried beyond into the deeper basin. Before 
 this improvement, the water spread out fan-like, and slackened 
 its velocity to such an extent that the mud was deposited in a 
 region where the water was already so shallow that navigation 
 became seriously obstructed. 
 
 5 
 
50 WALKS AND TALKS. 
 
 \ 
 
 Still, some of the sediment floats on beyond the bar. 
 There is a current in the Gulf which sets eastward along the 
 northern border, and bears Mississippi sediment as far as the 
 straits of Florida. The fine impalpable dust finally comes to 
 rest on the bottom of the Gulf. 
 
 A thousand rivers thus are bringing their contributions to 
 the sea. Around ten thousand miles of coast, the sea itself is 
 battering down the land. The coarser fragments are left 
 along the beach. The enfeebled action of the retreating surf 
 bears some distance seaward the smaller fragments and the 
 pebbles rolled and rounded on the beach. The finest sedi- 
 ments have no opportunity to subside till floated far from 
 shore. Thus the same assortment is exerted which we saw 
 effected by the torrent of the Aar. The ocean's bottom lies 
 covered to a vast extent with sheets of sedimentary materials 
 which, near the shore, are coarse, and remoter from shore are 
 progressively finer, as far as the finest sediments are floated. 
 This process goes forward before our eyes; it has been con- 
 tinued during all the thousands of ages past, since the ocean 
 first came into existence. How many layers must there be? 
 How many feet of sediments have been piled up ? What 
 conditions have they assumed while the geologic seons have 
 rolled by? 
 
 IX. THE RIVER GORGE. 
 
 EROSION. 
 
 WHENCE come the sediments which muddy the rivers and 
 fill the lakelets, and make even the oceans shallower? The 
 query must have occurred to you as we talked about the 
 abundance of sediments ; yet, simple as it is, comparatively 
 few people have considered it. These sediments must all come 
 from some source where they existed as solid, massive constit- 
 uents of our planet. They are portions of the planet trans- 
 ported from one position to another. Their transportation 
 changes the figure of the planet. Every film of sediment pro- 
 claims that the fashion of the planet has been worked over to 
 
THE RIVER GORGE. 51 
 
 some extent. The making of the planet has been merely a 
 progressive changing of the fashion of the materials of which 
 it is composed. If the completed planet as we see it is the 
 product of geological forces, then the work of sedimentation 
 proceeds by means of forces which are geological. The least 
 mentionable portion of that work is performed by such force. 
 The filling of boyhood's mill-pond was a geological work. 
 The slime settled by the roadside is a geological phenomenon. 
 These are results accomplished; let us see how far we can 
 trace them to their causes, and thus unfold a bit of the 
 world's history. 
 
 The sediments have been brought by moving waters ; we 
 must therefore trace the waters to their sources ; we must re- 
 trace their course from the higher level. Obviously, the 
 roadside slime has descended the rill-ways from the middle of 
 the street ; from the hill-slope down which a portion of the 
 water descended. Some water flowed down the field-slope, 
 moved under the fences, and found its course to the road-side 
 pool, bringing as much sediment with it as it had power to 
 bear. The corn-fields have been taxed ; the earth built into 
 the highway has been stolen ; the form and bulk of the hill 
 have been changed. So the farmer's fields contributed the 
 material which lies in the bottom of the mill-pond. To some 
 extent, the fields have been scraped down and impoverished. 
 There lies the farmer's property spread over a surface which 
 forms the floor of the sunfishes' home. 
 
 Over every square mile flows some stream. The smallest 
 stream, as well as the largest, occupies a valley; and down 
 its slopes descend the sediment-laden drainage waters which 
 seek the stream to join in its journey to the lower levels. 
 Follow the streamlet. Along every rod of its course we find 
 discharged during a rain the muddy washings of the land. 
 The streamlet grows. Many a lateral rill brings in its con- 
 tribution from the fields which stretch in another direction. 
 Our streamlet flows on, and sooner or later it discharges its 
 burden in some larger stream, which has already grown to its 
 present volume by the contribution of a score of streamlets 
 
52 WALKS AND TALKS. 
 
 higher up the valley. All are merged together; but we are 
 sure the water and the mud from our own village our own 
 farms are there with the rest. The stream moves on it 
 never rests and it grows as it moves. It courses across a 
 State ; it marks a boundary between States. Men have made 
 it a vehicle for floating logs ; a highway for skiffs and barges. 
 Now, the more pompous stream styles itself a river. It 
 hastens to join the Ohio and share in the dignity of floating 
 steamboats and carrying on the commerce of a populous 
 valley. The Ohio has even surpassed the tributary by which 
 we have been led, in taking on its cargo of mud. We stand 
 in the middle of the suspension bridge at Cincinnati and look 
 down on the yellow surface of the great stream. There go 
 the contributions from half a dozen States. There goes the 
 soil filched from our garden, or torn from our new-made road, 
 two hundred miles away. We know it is there. 
 
 Look on the map and notice how many rivers are bring- 
 ing their sediments to the Ohio. Trace these tributaries to 
 their sources. From how wide a territory is the mud gath- 
 ered which thus rushes down with the main river? Notice 
 that the Ohio carries its burden to the Mississippi. Look 
 again upon the map and see how many other great rivers 
 bring the mud from other far-off regions to concentrate it all 
 in the mighty Father of Waters. Here float sediments from 
 western New York, from West Virginia, from the Ozark Mount- 
 ains, from the Cumberland Table Land, from Minnesota, and 
 the Indian Territory. Here in this resistless tide floats the iden- 
 tical soil which was washed from Farmer Jones's potato field. 
 
 In this view, consider the great Missouri. It pours its 
 yellow stream into the clearer tide of the Mississippi a few 
 miles above St. Louis. I have stood on the deck of a steamer 
 between Alton and St. Louis and looked down on the Mis- 
 souri's turbid volume pushing far into the Mississippi, and re- 
 taining for miles a distinct boundary between the waters of 
 the two rivers. It appears that the contributions from the 
 far northwest exceed all those from the east. Follow the 
 whirling tide of the Missouri upward toward its sources. 
 
THE RIVER GORGE. 53 
 
 There stand great cities on its alluvial banks. The crumbling 
 bluffs by spells slide into the river. Above the limits of city 
 populations the river is already gathering' in the mud destined 
 to journey to the Gulf of Mexico mud which has already 
 been floated from some remoter region and deposited here at 
 times of overflow. Here comes the Niobrara, with slime from 
 the prairies of Nebraska; the Cheyenne, with washings from 
 the mining camps in the Black Hills ; the Little Missouri 
 and Yellowstone, with sands worn from the Big Horn, the 
 Wind River, and the Snow Mountains ; here, on a grassy 
 plain, unite the Jefferson, Madison and Gallatin tributaries, 
 which bring the dust of the continent from the high water- 
 shed of the Red Rock Mountains, which parts the continental 
 drainage to opposite points of the compass. It is a bewildering 
 breadth and complexity of operations. Over every foot of this 
 wasting expanse the land is yielding to the corrosive action of 
 rivers and rains and frosts. The proud mountain domes and 
 pinnacles are coming down to acknowledge the supremacy of 
 the powers of denudation. The Rocky Mountains have begun 
 their journey to the Gulf of Mexico. Cubic miles of their 
 granitic substance are buried in the delta of Louisiana and the 
 bar of the Mississippi. 
 
 Now that we discover in action the forces which could 
 transform the face of the land in some hundreds of thousands 
 of years, we take a new view of the aspects of the terrestrial 
 surface which had already been acquired when man came into 
 existence. We discover that the face of the earth had already 
 been transformed before we began our observations on it, and 
 by means of agencies which corroded the rocks and carried 
 away the materials precisely as the forces of nature are wast- 
 ing the continent before our eyes. We have already recog- 
 nized the fact that aqueous erosion cut through the Straits of 
 Mackinac and chiseled down the steep sides of the monumental 
 island in the Straits. We have seen the deep precipitous- 
 walled gorge of the Niagara, and the rock-bluffs bounding on 
 certain sides the basins of the great lakes the works of 
 rivers and waves. 
 
54 WALKS AND TALKS. 
 
 Every river, in its search for a resting-place, has cut a 
 way of even grade across the inequalities of the land, and the 
 rubbish has been dumped somewhere in alluvial border or 
 broad delta, or seaward rolling bar. The Tampa has sawed 
 a broad gash through the Uinta range on its way to the Green 
 river. The Green has cut a dark chasm down through the 
 plateaus of Colorado to the river whose colored waters, poured 
 in from the snow-born floods of the Rocky Mountains, gave 
 name to the river and the state. The Colorado, with aug- 
 mented force, has dug a deeper and a wider canon through 
 the shattered terraces of the southern half of the state. The 
 "Grand Canon" sinks vertically six thousand feet through 
 the rocks a terrific gash, like a sabre-cut from some of the 
 powers of Nature. 
 
 " It looks as if broken by bolts of thunder, 
 Riven and driven by turbulent time." 
 
 So a hundred rivers of the far west have scored the land. 
 So the Cumberland, the Kentucky, the Hudson, the James, 
 the Mississippi, by gentle worrying of the underlying rocks, 
 have plowed out channels whose steep walls rise as high as 
 the smoke from the steamer which utilizes the water-way. 
 We have not seen these works begun; but we see them in 
 progress ; and we feel bound in reason to infer that the rivers 
 have worked in the distant past as they, are working before 
 our eyes. 
 
 There are other erosions, however, which were effected not 
 only before human times, but by agencies which have disap- 
 peared from existence. There are the Catskill Mountains 
 essentially a mere wall of horizontally laid slabs of red sand- 
 stone. We have not detected Nature anywhere raising such 
 a wall. These mountains must be a remnant of a broad for- 
 mation once stretching far east and west. The forces of ero- 
 sion have worn away the formation on both sides, and the 
 Catskills stand forth a feature of relief, as the statue emerges 
 from the block of stone under the chisel of the sculptor. 
 Such, too, is the Cumberland Table Land, high up-raised like 
 a mountain, but yet not uplifted. It is a mere salience re- 
 
THE RIVER GOKGE. 55 
 
 suiting from the vast erosions that have taken place along its 
 western border. In central Tennessee, indeed, this erosive 
 process has excavated a basin a hundred miles in diameter, 
 bounded on all sides by the ragged edges of the formations 
 which were left. 
 
 So this completed work of erosive powers which have re- 
 tired from action is commemorated in many a monument-like 
 outlier in Wisconsin and Minnesota. A great formation 
 which once overspread many a township has all been carried 
 away, save here and there an isolated remnant which lies like 
 an island in the midst of geology of a different character. It 
 is the Potsdam Sandstone which has been thus eroded; but 
 wide areas still remain, and underlie portions of those states. 
 Similar are the columns in Monument Park, and the ruins in 
 the " Garden of the gods." Like the great basin of central 
 Tennessee are many of the excavations in the Bad Lands of 
 the Upper Missouri and in New Mexico. We shall have 
 other occasion to talk about these ; for they are burial places 
 of the brute populations which held possession of America 
 before the advent of man. 
 
 These two great processes, erosion and sedimentation, 
 must be vividly appreciated. The whole history of the visi- 
 ble land has consisted chiefly of up-building and destruction, 
 rebuilding and disintegration, by the action of forces which 
 have left gigantic monuments of their former power, and 
 are even in our times, working on a scale large enough 
 to illustrate to us how the foundations of the land were laid, 
 and how the face of the earth has been carved into the fashion 
 it presents to our interested eyes. 
 
 In another walk we must follow the sediments, under the 
 sea, and try to learn what goes on in the mysterious abysses 
 through which no highway has been opened. 
 
56 WALKS AND TALKS. 
 
 X. A \VALK: UNDER THE SEA. 
 
 WHAT GOES ON IN THE OCEAN DEPTHS. 
 
 "THE sea! the sea!" shouted the companions of Balboa, 
 as they caught the first glimpse of the Pacific from the heights 
 of the American Isthmus. The sea has always inspired the 
 wonder often the veneration of mankind. Its vastness and 
 power overwhelm the imagination. Its permanence, its an- 
 tiquity, form a bewildering conception. The same ''far- 
 sounding sea " roared in the hearing of the mariners of the 
 remotest past. The same ocean floated the ships of the Tyri- 
 ans and Carthaginians. Its mysterious depths aroused the 
 superstitions of the ancients as they excite the intelligent 
 curiosity of modern science. A "glorious mirror," as Byron 
 conceived it, 
 
 " Where the Almighty's form 
 Glasses itself in tempests. * * * * 
 
 Boundless, endless, and sublime, 
 The image of eternity the throne 
 Of the invisible." 
 
 Let us stand on some bold headland and look out over the 
 Atlantic. Let us plant ourselves on Sankaty Head, the east- 
 ern promontory of Nantucket, itself the "ultima Thule" of 
 New England. The breakers roar along the beach. Across 
 the billowy blue thought wanders to the European shore. 
 Underneath the ruffled surface imagination pictures a world 
 of curious and wonderful existences. There lie the skeletons 
 of noble ships there moulder the dead sailors of all nations 
 there rot invaluable cargoes there sleep the mysteries of 
 steamers which sailed out of sight of land and never returned 
 there swarm the sharks that desecrate the sacred forms of 
 humanity which sink into their silent empire. Shall we ven- 
 ture among the dangers of the under-world ? Yes, we invoke 
 the magic protection which has made warriors invulnerable, 
 and shielded adventurers upon the waters of Styx, and the 
 fiery waves of Phlegethon. 
 
A WALK UNDER THE SEA. 57 
 
 We go down like bathers in the sea. We pass the mar- 
 gin where 
 
 " The dreary back seaweed lolls and wags." 
 
 We traverse the borders where the brown, belted kelp sways 
 to and fro in graceful curves. We get beyond the slope of 
 stony bottom to the smooth sand. We come to the gardens 
 of the rosy-tinted sea-mosses the Dasya, the Grinnellia, the 
 Callithamnion ; and startle the blue-fish and halibut in their 
 safe seclusion. A moonlight gleam is here, and the water 
 also takes on the chill of evening. We pass on, and attain a 
 depth of half a mile. Our feet press into the finer sediments 
 derived from the land the dust of other ''continents to be.'' 
 The twilight has faded into a deep shade. The creatures of 
 the sea swarm curiously about us, then flee in terror from 
 our presence. We feel the gentle movement of "a river in 
 the ocean," but the surface disturbances do not reach even to 
 this depth. A change of climate impresses itself on our sen- 
 sations. The water where we started in had a temperature 
 of sixty degrees here it is forty. But we are panoplied 
 against harm ; we press on. We descend to the depth of a 
 mile under the sea. The curiously gazing species of the shal- 
 lower water appear no more. Their home is the zone which 
 now stretches above our heads. The green and rosy sea- 
 mosses never venture here. We are in total darkness ; no 
 chlorophyll tints the growths of th$ vegetable kingdom. Here 
 are only stony, white calcareous algse and silicious diatoms of 
 microscopic minuteness. 
 
 We pause to contemplate the awful stillness of the subma- 
 rine realm, and feel our slimy path down to the deeper pro- 
 found. Above us now float two miles of black sea. Any 
 surface fish brought down here perishes from the effect of 
 enormous pressure, if possessing an air-bladder. If it have 
 none, the fish becomes torpid, and finally dies. We are here, 
 probably miles from the shore that varies with the steepness 
 of the slope. The sediments which the rivers have brought 
 to the ocean have mostly been deposited between our starting 
 
58 WALKS AND TALKS. 
 
 point and this. But here still are some of the finest particles 
 contributed by the land slime from Louisiana, from Chau- 
 tauqua, from the Rocky Mountains, from our native town. 
 Will these far-brought and commingled atoms ever see day- 
 light again? 
 
 We are standing on the border of the vast abyss which 
 extends over half the area of the earth. It is an undulating, 
 silent desert. No diversity of mountain and valley, cliff and 
 gorge exists. We have read of submarine cliffs and plateaus, 
 but these are known only in the shallower ocean ; they are 
 features of the continental slope. By a gentle grade the bot- 
 tom descends to a depth of five miles. Over all this dread 
 waste, no rocks rise above the bed of slime. No fragments of 
 crystalline rocks have been brought up by the dredge. A 
 thousand miles away the bottom has been burst through by 
 an internal force, and lavas have heaped themselves up to the 
 height of a mile or two, or even to the actual surface ; but 
 no upheaval has brought to light from the abysmal floor any 
 trace of those hard crystalline rocks which we recognize as 
 " metamorphic " the sort of which our bowlders are formed. 
 There is no evidence that such rocks were ever produced in 
 that situation. 
 
 The pressure on us in this abysmal region is four or five 
 tons to every square inch. The water is ice-cold everywhere. 
 The darkness, absolute and palpable. A curdling revulsion 
 of feeling and purpose seizes us. We halt and reflect. We 
 turn our eyes upward with a painful longing for the " holy 
 light, offspring of heaven first-born." Only the black ceiling 
 appears. Two miles above us is the sunny sea, where all the 
 blue of a genial sky beams down. There float the ships in 
 summer calm upon a ''painted ocean," or tossed and rent by 
 the winter tempest which inspires the waves with madness. 
 But no summer and winter vicissitudes are here. No sun- 
 light ever penetrates this Cimmerian gloom. No sunrise, or 
 noonday, or sunset is ever known. As it was when the Gar- 
 den of Eden was first consecrated to man, so it has remained 
 and must remain. Not even the crash of thunders or the 
 
A WALK UNDER THE SEA. 59 
 
 roar of tempests can be heard. The huge wave, crested with 
 elemental fury, rolls on, but makes no stir in the stillness and 
 stagnation of the abysmal realm. 
 
 When we crossed the borders of this dark and silent abyss, 
 our feet sank in a white pasty slime which has been desig- 
 nated " Globigerina ooze." The dredges of the CJiallenger 
 and the Albatross have been down here, hung by a piano 
 wire over the stern of the vessel, and samples of this ooze 
 have been studied. We find it composed chiefly of micro- 
 scopic dead shells called Fo-ram-i-nif'-e-ra, together with others 
 called Pter'-o-pods. The little creatures which formed the 
 shells do not live here ; they dwell in calm zones of water far 
 above. When the conscious animal ceases to live, its tiny 
 house sinks down into this dark world. And thus, as the 
 ages roll by, the fine chalky rain slowly accumulates upon the 
 bottom. When this ooze is dried and hardened, it resembles 
 the chalk of Europe ; and when that is microscopically ex- 
 amined, we find in it the same little Foraminifera. These are 
 important geological facts, which, though they come out of 
 an abyss of darkness, throw a vivid light on equally dark 
 chapters of the world's long-past history. 
 
 We have groped our way down three and four miles be- 
 neath daylight. A sort of ooze still overspreads the bottom ; 
 but it is not the Globigerina and Pteropod ooze. It is a fine 
 rusty clay. But the white shells are not wanting because the 
 tiny creatures which secrete them are not overhead. They 
 swarm there as elsewhere, far from land with other pelagw 
 forms. But the fragile matter of the shell is dissolved before 
 it reaches this great depth. Only the aluminous and insolu- 
 ble constituent reaches the bottom. This clay ooze possesses 
 other interest. Disseminated through it are minute crystals 
 of such minerals as escape through the throats of volcanoes 
 into the upper air. Here are the dust particles which have im- 
 parted a ruddy glow to many a past sunset. Once the source 
 of the roseate glory of the twilight hour, they lie now, in im- 
 penetrable darkness and the repose of death. How changed 
 the fortune of the little particle. It floated for months in the 
 
60 WALKS AND TALKS. 
 
 upper thin air in the film of space which separates earth 
 from heaven borne hither by the simoon, thither by the anti- 
 trades, hurled in the vortex of a cyclone and precipitated in 
 mid-ocean by a down-falling mass of vapor. Then, perhaps, 
 seized by the waves, and rocked and beaten at the surface till 
 it reached a zone of calm, it began its silent descent into the 
 dark world where it is destined to rest undisturbed for 
 centuries. 
 
 Here too is cosmic dust. The seeds of worlds have been 
 sprinkled through space, and some of them have been planted 
 in the soil of this abyss. These minute globules of magnetic 
 iron were sparks emitted from a burning meteor. The meteor 
 was a small mass or particle of material stuff coursing swiftly 
 through the cold interplanetary spaces. It pierced the atmos- 
 phere of the earth ; the friction resulting ignited the meteor, 
 and for a brief moment it painted a fiery streak in its flight, 
 when all had been transformed to ashy particles which floated 
 in the air like volcanic dust, until it found, at last, a 
 resting place in the cold bed of the Atlantic. What a rever- 
 sal of fortune was here ! The particle might have swept on 
 through space, as many of its companions did, until it became 
 part of a glowing comet. Perhaps it once shone in a star 
 now it is dead for a cycle of ages. It is an impressive 
 thought that here, in this rayless night, we find the black 
 ruins of a star. The realities of material history exceed in 
 wonder all the fictions of imagination. 
 
 We still stand wondering over the scene which surrounds 
 us. How oppressive is this silence. How welcome would be 
 the cheerful chirp of the sparrow. Even the piping of the 
 hated mosquito would break the eternal monotony. From 
 age to age this reign of death persists. A chill which is more 
 than icy, pierces us to the marrow. Sometimes, as we grope 
 through the Egyptian gloom, we kick the bones of aquatic creat- 
 ures which have perished in the water above us. Often their 
 kind is still in existence ; but sometimes their species are long 
 extinct. Here are teeth of sharks and ear-bones of whales 
 which have lain during geologic ages. Grand vicissitudes 
 
A WALK UNDER THE SEA. 61 
 
 have passed by, which transformed the aspect of continents, 
 but these relics lay here undisturbed unburied so slowly do 
 the sediments accumulate. 
 
 But there is indeed life here. Sparse, quaint life ; and 
 the species are of archaic and embryonic forms ; that is, they 
 resemble creatures which lived in the earlier ages of the 
 world, or creatures which have undergone but a part of their 
 development crude, uncouth, and alien to the modern world. 
 Here are Crinoids, or Stone Lilies, which, in all other waters, 
 have perished from the earth save one species long known in 
 the Caribbean Sea. They are an antique type. But from 
 deep waters off the coasts of Florida and Norway, comes up, 
 with other forms, Rhiz-od-ri-nus, a genus which disappeared 
 from shallow seas unknown millions of years ago ; but here, 
 where nothing changes, it has perpetuated its existence 
 through half the history of the world. Between death and 
 the changeless life which here reigns, the difference is slight. 
 
 Still more startling in their grotesqueness, are some of the 
 fishes which lie here more than half buried in the mud. Here 
 is one fashioned like a scoop-net. The long, slender body is 
 the handle, and the net is an enormous pouch under the chin, 
 which would take in the whole of the body three times over. 
 Another hangs like an open wide-mouthed meal-bag. In this 
 case, also, the bag hangs suspended from the part where the 
 throat should be. The diminutive body is noticed as an ap- 
 pendage attached to the back side of the bag. It is known by 
 the fins. Four of these bodies might be contained in one 
 pouch. A different, but equally erratic form brandishes an 
 attenuated body like a whip-lash appended to an enormous 
 head, exposing an eye which is nearly half its own diameter. 
 Still again, we note a shark-like form, with enormous gape 
 and horrid teeth, having a range of spines along each side of 
 the slender body, above and below, and, most curious of all, 
 a long, thread-like organ depending from beneath the chin, 
 with a tassel-like tentacle bearing structures for feeling, at the 
 end. Indeed, this reminds us of the piano wire with dredge 
 at the end, which went feeling for examples from this so-called 
 
62 WALKS AND TALKS. 
 
 Jbassalian fauna, and brought up the very prototype of its own 
 mechanism. 
 
 But see ! somebody is here with a lantern. How sleepily 
 the light gleams in the darkness. There is no fire in it. 
 Something it is. An animated lantern. A lantern without 
 a flame. It is another strange fish. It is phosphorescence 
 which gleams mildly from his shiny sides. Still another lan- 
 tern-bearing fish. Here are luminous plates beneath the eyes; 
 behind them, in a cavity, retinal tissue, as if these structures 
 were planned for eyes ; but they are not eyes. Real eyes are 
 present. We discover, then, faint relief from the palpable 
 darkness in which we have groped. 
 
 But our task is done ; our curiosity is gratified ; we have 
 glimpsed the underworld, and have gathered observations on 
 which we shall ponder, many a day. Let us now, like the 
 heroes of epic song, ascend to the light of the upper world. 
 
 XI. BY THE ROCKY 
 
 STRATA AND THEIR CLASSIFICATION. 
 
 LET us walk in front of the precipice which frowns along 
 the hill-side near the village of Panama, on the west. It is 
 no more instructive than a thousand other cliffs, but it may 
 be more convenient to reach. The cliff rises fifty or sixty feet 
 and presents a broken and rugged front. The brown and yel- 
 lowish rock is composed of fine silicious grains, with small im- 
 bedded pebbles, and thus answers the description of a con- 
 glomeritic sandstone. The face of the cliff shows several 
 yawning fissures extending from bottom to top. The winter 
 snow drifts into these in such abundance as to remain, some- 
 times, till midsummer. One of these chasms is known, there- 
 fore, as the " Ice House." You observe that this precipice is 
 composed of layers of sandstone piled one above the other. 
 These are strata, and the whole formation is stratified. [Notice 
 that one of these layers is a stratum not "a strata;" and we 
 must never say " stratas."] You observe, also, that some of 
 
BY THE ROCKY WALL. 63 
 
 the strata are composed of lamince which run obliquely across 
 the stratum. This is oblique lamination. It is of the same 
 nature as we saw in the semi-stratified drift. We concluded 
 that such mode of arrangement was caused by torrential 
 action. A similar explanation is allowable here, but the 
 water was less turbulent; it was, perhaps, wave action along 
 a beach. 
 
 At Watkins' Glen, at the south end of Seneca Lake, is a 
 wild, deep gorge cut by a stream which rushes down from 
 the highland on its way to the lake. It is a striking example 
 of erosion, and the materials carried away are deposited in 
 Seneca Lake. The rocks here are shales. They are thin- 
 bedded, and soft enough to be cut with a knife. We see no 
 oblique lamination. This is a fine example of another sort of 
 strata. At Rochester, where the Central Railroad crosses the 
 Genesee river, a few rods above the Falls, we look down into 
 a gorge eroded by the river. The high walls of the gorge are 
 distinctly stratified ; and here many of the strata are com- 
 posed of limestone. No traces of oblique lamination can be 
 found in limestones. If we go to Portland, in Connecticut, 
 we may look down into wide and deep excavations in a sand- 
 stone rock of a brownish color, and very evenly bedded. 
 Near Cleveland, and at Berea, Ohio, are extensive quarries in a 
 grayish and bluish gray sort of sandstone. At Cincinnati, 
 back of the city, we find a steep slope formed of beds of lime- 
 stone, shale, and clay. Descending the Mississippi from St. 
 Paul to St. Louis, we see high cliffs of buffish strata overlook- 
 ing the river at frequent intervals now on the west, now on 
 the east. At St. Paul the rocks are distinctly stratified lime- 
 stone. At Davenport and St. Louis we find other kinds of 
 limestones. 
 
 Now, I have directed your attention to these few exam- 
 ples out of hundreds for the purpose of enabling you to un- 
 derstand that everywhere solid rocks underlie the Drift; and 
 that they are, at least very generally, stratified rocks, and are 
 composed chiefly of sandstones, limestones, and shales. Let 
 us consider how these solid strata have been produced. None 
 
64 WALKS AND TALKS. 
 
 of these have we ever seen making ; but I think we have seen 
 a process similar to rock-making in the beds of alluvial mat- 
 ter deposited by an overflowing stream. In traveling down 
 the lower Mississippi, we can see from the deck of the steamer 
 that the material of the alluvial banks is horizontally strati- 
 fied. More strictly we should say that it is laminated ; but 
 the nature of the geological work is the same in either case. 
 Now, if those alluvial banks should become firmly consoli- 
 dated, they would present the appearance of some of the rocky 
 cliffs those in Watkins' Glen, for instance. You have also 
 learned how large quantities of sediments borne down by 
 rivers are carried out to sea many miles, and slowly deposited 
 on the ocean's bottom. These deposits must necessarily be in 
 layers, each of which is spread evenly over the bottom. You 
 remember that the distance to which materials of a certain 
 degree of coarseness may be carried before sinking to the 
 bottom, depends on the velocity of the motion of the water. 
 At a certain place in the sea the velocity is undoubtedly more 
 rapid at one time than another. The motion is caused by 
 winds, by tides, and by currents. Therefore, a coarser sheet 
 of materials will be laid down at one time, and a finer sheet at 
 another. The alternations of coarser and finer render the 
 bedded arrangement conspicuous. Very likely the colors of 
 the sediments will vary also ; since, from one direction, they 
 may be supplied by pulverized limestone, from another by 
 pulverized sandstone, and from another by pulverized shale, 
 which may be blue, red, or black. We noticed, too, in our 
 walk under the sea, that sedimentary materials are spread 
 over all the slope of the ocean's floor, within fifty or a hun- 
 dred miles of the land often much farther, if the shore is 
 "shelving" or the currents are favorable. 
 
 These various indications compel us to adopt the conclu- 
 sion that water has been the agent by which the materials of 
 the stratified rocks have been spread out in broad beds or 
 strata. But, though river overflows must leave the sediments 
 in a bedded condition, these beds are not exactly like those 
 seen in great formations of limestone and sandstone. Kiver 
 
BY THE ROCKY WALL. 65 
 
 sediments never have so wide an extent as the strata which 
 underlie a continent; nor are they generally so evenly bedded 
 as our ordinary rock-strata. We must conclude, therefore, 
 that the watery action which arranged the sediments from 
 which our rock-strata have been formed, was a very widely 
 operating action. There is no watery action known sufficiently 
 wide-spread except the action of the ocean. In the ocean, 
 sediments are now settling down in sheets a thousand miles 
 broad. This conclusion is a somewhat startling one. It im- 
 plies that, wherever rocky strata exist, there the ocean's waters 
 have stood. Rocky strata are found hundreds of feet above 
 the level of the ocean, and the fact seems incompatible with 
 our conclusion. The average level of all the northern and 
 northwestern states is from six hundred to a thousand feet 
 above the sea. If the underlying strata were deposited by 
 the ocean, then either the ocean has greatly subsided in later 
 times, or regions which were once sea-bottom have been ex- 
 tensively uplifted. 
 
 These subjects have attracted the attention of thoughtful 
 observers for a century indeed, for two or three centuries. 
 The question has been much discussed ; but no doubt is longer 
 entertained that the sea has covered all the land, and that the 
 exposure of land has resulted from upheaval of portions of 
 the ancient sea-bottom. Many confirmations of this view will 
 be discovered as we proceed. Thus by a very simple and easy 
 process of observation and reasoning we have reached a very 
 fundamental principle in geological science; and you under- 
 stand the evidence on which it rests. 
 
 Now, if all the strata which underlie the land are formed 
 from marine sediments, the time required for their accumula- 
 tion must have been enormous. We have made observations 
 along the sea-shore, and have formed some conception of the 
 rate of sedimentation over a belt near the land. There are 
 times when violent winds cause the waves to wear down the 
 shore at such a rate that the sea, for a mile from shore, be- 
 comes turbid with sediments. This has been seen often at 
 Long Branch and Coney Island. But these periods are of 
 
 6 
 
66 WALKS AND TALKS. 
 
 short duration, and the deposits at the distance ot ten miles 
 from land are no longer conspicuous. In the vicinity of coral 
 reefs and islands the attrition of the waves imparts a milky 
 complexion to the sea, especially during the prevalence of a 
 storm, and the calcareous particles are floated sometimes a 
 hundred miles and more. But it is apparent that, as a rule, 
 the sea floats too little sediment to build up a formation in any 
 other than a very gradual manner. We noticed, also, in our 
 walk under the sea, that the bottom sediments grew thin with 
 distance from the shore, and that those of continental origin 
 ceased entirely at about two miles in depth. When now we 
 remember that the stratified rocks are over a hundred thou- 
 sand feet in thickness, we perceive immediately that the 
 process of sedimentation has been an extremely long one. 
 
 We have then to consider what changes may have taken 
 place in the conditions of the world during so long a period. 
 Probably the nature of the sediments has been changed from 
 time to time by these changes in the physical conditions of 
 the planet. We do not wish to anticipate conclusions to be 
 rested on facts which have not yet fallen under our observa- 
 tion; but every body has noticed that the surface of the earth 
 is undergoing changes ; and these, in thousands of years, must 
 aggregate amounts which transform the aspects of the planet. 
 We have lived to see lakelets filled ; new channels formed for 
 great rivers ; ocean beaches consumed by the waves ; hundreds 
 of miles of continental coasts upraised or sunken as in Chili, 
 Scandinavia, and Greenland ; new islands bursting into view ; 
 whole provinces shattered by earthquakes. Suppose our ob- 
 servation extended back a million years, and the tenor of 
 events had been the same as in modern times ; is it not cer- 
 tain that changes must have aggregated to such an extent that, 
 waking at times to distinct consciousness of the greatly 
 changed conditions, we should from seon to aeon have felt ready 
 to declare a new chapter of the world's history had begun ? 
 I think so reasoning only from the physical data which, so 
 far, have engaged our attention. But we shall hereafter make 
 the acquaintance of many other facts which will confirm this 
 
MYSTERIOUS FORMS OF LIFE. 67 
 
 conclusion. Geologists have considered these facts, and have 
 settled on the principle that the long history of sedimenta- 
 tion has been divided into aeons corresponding to successive 
 conditions of the world. Names have been assigned to these 
 seons. Thus, the first series of sediments formed the strata 
 which lie deepest of all. They are called Eozoic, and the 
 aeon during which they were accumulating is the Eozoic jEon. 
 We will not pause here to inquire what these sediments rested 
 on in other words, what kind of rocks formed the bed of the 
 sea, at the beginning of that ^Eon. The ocean must have had 
 some solid bottom ; but of course, it was a bottom formed when 
 there was no ocean; for otherwise, the Eozoic strata would 
 not be the bottom strata. 
 
 The Eozoic GREAT SYSTEM of strata is at least fifty thou- 
 sand feet thick. In the next aeon the changed conditions 
 gave origin to changed strata. They constitute a Great Sys- 
 tem known as the PALAEOZOIC ; and the time during which 
 this system of strata was accumulated, is the PALEOZOIC 
 JEoN. Next after this, came the MESOZOIC JEow, during 
 which the MESOZOIC GREAT SYSTEM of strata was accumu- 
 lated. Lastly, followed the C^EN'-O-ZO-IC jiEoN, which contin- 
 ues to the present. The strata formed constitute the C^NO- 
 zoic GREAT SYSTEM. Now, before we take another walk, 
 these names must be well learned. 
 
 MYSTERIOUS F^ORMS OR 
 
 FOSSILS. 
 
 EVERY one has noticed the curious forms found in the 
 Drift, which so much resemble shells and corals, and buttons 
 or beads. Often they lie loose in the soil ; and often we see 
 them imbedded in fragments of limestones and sandstones 
 which are sometimes bowlders transported from a distance, and 
 sometimes fragments derived from a neighboring ledge or out- 
 crop of stratified rocks. In the cliffs at Panama are occasional 
 traces of shells, both bivalve and univalve. The latter 
 
68 WALKS AND TALKS. 
 
 is a little shell three-quarters of an inch in diameter, and 
 closely coiled almost in a plane, like a watch spring. I have 
 been amused to hear some of these forms like bivalve shells 
 called " petrified butterflies." Through western New York, 
 Ontario, Michigan, Ohio, and Indiana we find in the Drift 
 innumerable masses popularly known as "petrified honey- 
 comb," and " petrified wasp-nest." There are also quantities 
 of little flat discs like " buttons," each with radiating striae 
 or other decorations, and having a hole in the middle, as if 
 intended to be strung like beads. These have sometimes been 
 styled " St. Cuthbert's beads." 
 
 These curious forms, so much like animal structures, were 
 wondered over, hundreds of years ago. Very few persons 
 would then entertain the suggestion that they are real relics 
 of living things. They indeed bear the similitudes of marine 
 creatures ; but such they can not be, it was argued, because 
 they lie hundreds of feet above the sea. Some of the early 
 Italian writers attributed them to " the influence of the stars ;" 
 but Leonardo da Vinci demanded " where, in the hills, are the 
 stars now forming shells of distinct ages and species? And 
 how can the stars explain the origin of gravel, occurring at 
 different heights, and composed of pebbles rounded as if by 
 the motion of running water ?" Others attributed these forms 
 to the influence of a " plastic force" in nature. Agricola, a 
 German miner, conceived the notion that a " certain fatty 
 matter, set into fermentation by heat, gave birth to fossil or- 
 ganic shapes ;" Fallopio thought that petrified shells were gen- 
 erated by fermentation in the spots where they are found ; or 
 that they had, in some cases, acquired their form from the 
 "tumultuous movements of terrestrial exhalations." Olivi 
 thought fossils were mere "sports of nature," and some in- 
 dulged in the amusing fancy that they were "prototypes" or 
 " models" after which the Creator subsequently fashioned the 
 living creatures of the sea ; and others held that they were 
 "created" just as we find them. The last opinion I have 
 heard dogmatically asserted in America ; and probably it still 
 survives. 
 
MYSTERIOUS FORMS OF LIFE. 69 
 
 When it became impossible to resist the evidence that these 
 forms were relics of the sea, the theory obtained a foothold 
 that, as the deluge of Noah had inundated the lands, these 
 forms must be the relics of that recognized universal submer- 
 gence. It required a century and a half to argue down this 
 error ; and, meantime, the geologists who did not subscribe to 
 it, fell under the accusation of " disbelieving the whole of the 
 Sacred writings." 
 
 Thus, in our day, we stand at the outcome of a contest of 
 three hundred years; and, instead of battling against these 
 old errors, we find ourselves in a position to push on to new 
 discoveries. 
 
 That the sea has covered the land, and that shore lines 
 have greatly changed, was taught by Pythagoras, and after- 
 ward by Strabo and Pliny ; but these views were almost for- 
 gotten. Many Arabian writers have left on record views and 
 opinions on many subjects, quite in advance of their European 
 contemporaries. On this subject we find an entertaining reve- 
 lation of opinion by Mohammed Kazwini, of' the seventh cen- 
 tury of the Hegira the close of the thirteenth century of our 
 era. It is given as the narrative of Kidhz, an allegorical 
 personage: 
 
 " I passed one day by a very ancient, and wonderfully 
 populous city, and asked one of its inhabitants how long it 
 had been founded. 'It is indeed a mighty city,' replied he, 
 ' we know not how long it has existed, and our ancestors were, 
 on this subject, as ignorant as ourselves.' Five centuries after- 
 wards, as I passed by the same place, I could not perceive 
 the slightest vestige of the city. I demanded of a peasant 
 who was gathering herbs upon its former site, how long it had 
 been destroyed. 'In sooth a strange question/ replied he, 
 'the ground here has never been different from what you 
 now behold it.' ' Was there not of old,' said I, 'a splendid 
 city here?' ' Never,' he answered, 'so far as we have seen, 
 and never did our fathers speak to us of any such.' On my 
 return there five hundred years afterwards, I found the sea in 
 the same place, and on its shores were a party of fishermen, 
 
70 WALKS AND TALKS. 
 
 of whom I inquired how long the land had been covered by 
 the waters. * Is this a question/ said they, ' for a man like 
 you? This 'spot has always been what it is now/ I again re- 
 turned five hundred years afterwards, and the sea had disap- 
 peared. I inquired of a man who stood alone upon the spot, 
 how long ago this change had taken place ; and he gave me 
 the same answer as I had received before. Lastly, on com- 
 ing back again, after an equal lapse of time, I found there a 
 flourishing city, more populous and more rich in beautiful 
 buildings than the city I had seen the first time; and when I 
 would fain have informed myself concerning its origin, the in- 
 habitants answered me, ' Its rise is lost in remote antiquity ; 
 we are ignorant how long it has existed, and our fathers were 
 on this subject as ignorant as ourselves.'" 
 
 This allegory sets forth the nature of the modern scientific 
 conception of changes in relative positions of land and sea. It 
 must not, however, be understood that continents ever occu- 
 pied the sites of the modern oceans ; though these oceans once 
 extended over all the lands. 
 
 Thus these strata of sandstone, limestone, and shale are real 
 ancient sea-sediments, as we have already argued ; and these 
 forms of life imbedded in the strata are the relics of the ani- 
 mals which dwelt in the sea while the sediments were accu- 
 mulating. If so long a time as we have concluded was re- 
 quired for the deposition of these materials, then, assuredly, 
 the one hundred and fifty days of the Noachian inundation 
 were egregiously inadequate. 
 
 Moreover, if we subject these relics to critical examination, 
 we discover that their resemblance to living forms is in fun- 
 damental characters only. As to particular species, we find 
 none, save in peculiar situations, which are identical with liv- 
 ing species. We find them less like living species than the 
 leopard is like the tiger, or the hen-hawk like the snowy owl. 
 To maintain, as the old theologians did, that modern species 
 are descended from species whose relics are fossilized in the 
 rocks, is to advocate a theory of transformation which would 
 have been startling, if they could have appreciated the facts. 
 
MYSTEKIOUS FORMS OF LIFE. 71 
 
 Modern evolution, which maintains such a descent, allows mil- 
 lions of years for the accomplishment of the transmutations; 
 but the diluvialists never claimed over five thousand years, and 
 resented the offer of geology to place more time at their disposal. 
 
 If the relics buried in the rocks present undoubted diver- 
 gences from living forms, it must be because they lived in 
 other ages, and under different physical conditions from mod- 
 ern species. As there is now, so there must always have been, 
 some co-ordination or suitability between the conditions in 
 which species lived, and the structures, instincts, and capabili- 
 ties of the species. We are witnesses of this great prin- 
 ciple the adaptation of organism to environment. The Hippo- 
 potamus and the Elephant, dwellers in warm climates, are 
 almost naked. The White Bear and the Arctic Fox, dwellers 
 in the frigid zone, are densely clad in fur. , The Duck is im- 
 pelled by its instinct to the water; so its feet are webbed to 
 adapt it to movement in the water. These co-ordinations of 
 structure to environment or surroundings, are everywhere 
 seen, and possess extreme interest. Let me ask you, my 
 reader, to study out a great many other examples. 
 
 Now, during the long history of rock-accumulation, there 
 must have taken place very great changes in the conditions 
 of the world. This may be inferred from the fact that some 
 changes are taking place before our eyes; and also from the 
 fact, which we must admit, that the ocean was once universal, 
 but is now interrupted by wide continental expanses which 
 deflect the winds and the currents of the sea, and modify the 
 climates of many regions. It might thus be inferred before- 
 hand, that the populations of the world have shown a corre- 
 spondence with the changing conditions of the world. If the 
 physical world has improved if it has undergone a progres- 
 sion from some cruder condition to the present, then the pop- 
 ulations of the world have progressively improved ; and we 
 shall find the records of this improvement in the fossil re- 
 mains of those populations, as we hunt for them in strata 
 farther and farther from the surface that is, farther and far- 
 ther removed in their origin from the present time. 
 
72 WALKS AND TALKS. 
 
 Now, with this preparation of mind, permit me to state 
 what has been ascertained by studying the fossils imbedded 
 in the succession of strata. The deepest rocks of which we 
 have any knowledge are those already named Eozoic. They 
 are mostly hard and crystalline such as we find in our in- 
 numerable bowlders. They were stratified originally, never- 
 theless ; they were marine sediments, and if any marine crea- 
 tures lived at the time, their relics were inclosed in the sedi- 
 ments. But you see how greatly the sediments have been 
 changed to make of them granites arid gneisses. If the 
 change almost or completely obliterated the lines of bedding, 
 it must also have destroyed most traces of the included fossils. 
 As a fact, almost no fossil remains are found. Yet a few 
 have been preserved to us. I do not intend to describe them 
 at present ; but you may learn that they belong to the very 
 lowest grade of animal life. The ages during which they 
 existed may be styled the REIGN OF PROTOZOANS. 
 
 The strata next above, in the lower part of the Palaeozoic 
 Great System, abound in the remains of marine animals; but 
 no traces of fishes or other vertebrates have been found. 
 This was the REIGN OF MARINE INVERTEBRATES. Their 
 exclusive remains extend through two systems, Cambrian and 
 Silurian. In the next higher formations we detect the bones 
 and teeth and armor-plates of fishes. There were many in- 
 vertebrates also, but, as the fishes were dominant in rank and 
 prowess, we designate this age the REIGN OF FISHES. The 
 strata deposited during this Reign form the Devonian System. 
 Next came the relics of the first air-breathers which ever 
 lived. We find their bones resembling those of modern sala- 
 manders or amphibians, though often much more powerful. 
 This was the REIGN OF AMPHIBIANS ; and the corresponding 
 strata are the Carboniferous System. The Cambrian, Silurian, 
 Devonian, and Carboniferous systems make up the Palaeozoic 
 Great System. 
 
 Next, as stated in our last Talk, come the strata which 
 form the Mesozoic Great System. Through this, in. addition 
 to relics of amphibians, fishes, and invertebrates, we find for 
 
MYSTERIOUS FORMS OF LIFE. 
 
 73 
 
 the first time the bones and teeth of reptiles. These creatures 
 offer extraordinary interest for us, and we shall take up the 
 study of them in due time. Their empire is known as the 
 REIGN OF REPTILES. Following this was the REIGN OF MAM- 
 MALS, since their bones are found distributed through the 
 Gznoz&ic Great System of strata. Lastly came man. His 
 bones and works are confined to the surface of the earth. 
 They are not found imbedded in solid rocks. This last and 
 highest animal characterizes the REIGN OF MAN. This is a 
 grand progression. These are fundamental conceptions in 
 geological science. They must be made perfectly familiar to 
 the student of Natural history. 
 
 As the reader will desire frequently to refer to this classi- 
 fication of formations and of organic history and geological 
 time, I insert the facts in a Table : 
 
 TABLE OF GEOLOGICAL HISTORY. 
 
 GRKAT SYSTEMS, 
 
 OK JBOMfl. 
 
 SYSTEMS, on. 
 AGKS. 
 
 GROUPS, on PERIODS. 
 
 ORGANIC REIGNS. 
 (Highest Fossils.) 
 
 
 QUATERNARY 
 
 Recent 'i 
 Champlain > 
 Glacial ) 
 
 MAN. 
 
 C^ENOZOIC.... 
 
 TERTIARY 
 
 Pliocene ) 
 Miocene > 
 Eocene ) 
 
 MAMMALS. 
 
 MESOZOIC 
 
 CRETACEOUS 
 
 Upper Cretaceous ' 
 Middle Cretaceous 
 Lower Cretaceous 
 f Wasatch ! 
 
 REPTILES 
 
 
 
 Nevada 
 
 
 
 TRIASSIC 
 
 /Star Peak 
 
 
 
 
 IKoipnto 
 f Permian 
 
 
 
 1 UPPER CARBON- 
 
 < Coal Measures 
 
 
 
 LOWER CARBON- 
 
 ( Conglomerate Measures 
 ("Carboniferous Lime- 
 
 AMPHIBIANS 
 (Land Animals). 
 
 
 IFEROUS 
 
 (Catskill (Waverly) 
 f Chemung 
 
 
 
 
 I Hamilton 
 
 FISHES 
 
 PALAEOZOIC.. 
 
 j DEVONIAN 
 
 1 Corniferous f 
 
 (Marine Verte- 
 
 
 
 I Oriskany 
 
 brates). 
 
 
 
 {Helderberg "I 
 
 
 
 SIT-URTAN, 
 
 Salina 
 
 
 
 (Upper Silurian). 
 
 Niagara 
 
 
 
 
 ( Trenton ' 
 
 
 
 CAMBRIAN, 
 
 
 
 
 (Lower Silurian). 
 
 (Primordial 
 
 
 EOZOIC 
 
 J HURONIAN 
 
 ((Undivided) \ 
 
 PROTOZOANS. 
 
 
 
 
 
74 WALKS AND TALKS. 
 
 I have included also in the foregoing table a column for 
 Groups or Periods, because some readers will be glad of this 
 more detailed information. This is a dry and unadorned 
 skeleton; but geology knows how to clothe it in flesh 
 and beauty. 
 
 XIII. COURSES OK THE EARTH'S MASONRY. 
 
 HOW THE FORMATIONS ARE ARRANGED. 
 
 FIRST, let me explain what is meant by a formation. It is 
 the mass of rock resulting from some action continued uni- 
 formly to a conclusion or a pause. It was indicated in our 
 last Talk that the conditions of the world must have changed 
 from time to time, and that the nature of the ocean sediments 
 must have changed correspondingly. The sediments laid 
 down during the time in which we conclude to say no change 
 occurred, are one formation. After this, a slight change 
 would result in another formation. But these two formations 
 may much resemble each other, though decidedly different 
 from the contiguous formations above and below. These two 
 formations together may, therefore, be said to constitute a 
 formation in a larger sense, accumulated during a 'time when 
 the main action continued the same, though in subordinate 
 particulars it changed. Formation, therefore, is a general 
 term, not always signifying the same amount of accumulation 
 nor even the same range of diversity. We may employ it in 
 various applications, and we shall find it convenient to have 
 such a term. A System is a "formation;" a Great System 
 is a "formation ;" a coal-bed is a "formation ;" a river-terrace 
 is a "formation," and a metallic vein is a "formation." I 
 must state, however, that the term is not employed by all 
 geologists in this indefinite sense. 
 
 Glancing back, now, to the beginning of sedimentary for- 
 mations, we recognize two principles which must be accepted. 
 First, the oldest or lowest sedimentary formation must have 
 rested on a foundation not sedimentary. The nature of that 
 foundation will have some light thrown upon it after we have 
 
COURSES OF THE EARTH'S MASONRY. 75 
 
 proceeded a little farther with our talks. Secondly, since the 
 lowest rocks of which we can gain any knowledge are not 
 such non-sedimentary foundation, we are unable to affirm 
 that we have ever explored to the bottom of the sedimentary 
 rocks. There may have been underneath, originally, a vast 
 additional amount of strata. We will study the oldest strata 
 accessible to us, and observe how they lie in respect to the 
 later strata. 
 
 If we travel over the surface of the country, we find it 
 generally overspread by loose materials which, in the northern 
 states are the so-called Drift. But here and there the bed- 
 rocks appear at the surface. That is, they outcrop. The na- 
 ture of the outcropping rocks is various. Sometimes they 
 are limestone, sometimes sandstone, sometimes shale, some- 
 times granite or some other sort of crystalline rocks. It seems 
 at first, as if every thing were in a state of confusion. But 
 let us be patient ; we shall discover order. We shall perceive 
 that one sort of stratum passes under another, and perhaps at 
 the distance of some miles, comes to the surface again. We 
 shall notice that a different stratum or formation passes under 
 this, and then perhaps comes to the surface again at some 
 point still more distant as if they were three wooden dishes 
 in a pile J., the largest; B, the next in size, and 0, the 
 smallest. B goes down under 0, and comes up beyond C. 
 A goes down under B, and comes up beyond B, on the op- 
 posite side. Many times numerous successive strata are nested 
 in each other precisely in this fashion. The lower peninsular 
 of Michigan is a good example. If you refer to the Table on 
 page 73 you will see that the Coal Measures are underlaid 
 by the Conglomerate Measures, the Carboniferous Limestone, 
 the Catskill Group, the Chemung Group, the Hamilton 
 Group, and the Corniferous Group. Each of these formations 
 underlies the peninsula in the form of a broad, shallow dish. 
 The Corniferous Group is at the bottom. Its margin comes 
 to the surface in southern Michigan. You see it in the lime- 
 stone at Monroe and throughout that region. Thence it 
 passes under the state and comes to the surface again at Old 
 
76 WALKS AND TALKS. 
 
 Mackinac and Cheboygan. Mackinac Island, which we have 
 talked about, is of Corniferous Limestone. The eastern mar- 
 gin of this dish is at London, in Ontario, and the western is 
 under Lake Michigan. A little nearer the center of the state 
 we find the margin of the next overlying group the Hamil- 
 ton. So the other groups follow as the successively smaller 
 dishes. The top dish consists of the Coal Measures. It is a 
 pretty flat dish, however, since the middle is about as high 
 as the margin. 
 
 That is one kind of arrangement which we observe. More 
 frequently, however, the arrangement is more like a pile of 
 long, broad, thin troughs without ends. In this case you per- 
 ceive that each formation goes down on one side and comes 
 up on the opposite side. But at the ends, they may not ap- 
 pear at the surface. Such an arrangement of strata is 
 called synclinal, and the line along the middle is the 
 synclinal axis. 
 
 Still another arrangement is quite as common. Suppose 
 we turn our nest of wooden dishes upside down, and suppose 
 that is their natural position. They represent so many for- 
 mations still. Then suppose we saw through the nest hori- 
 zontally in such place as to saw off all the bottoms except that 
 of the smallest dish. It is done. Now you see the edges of 
 the formations presenting themselves in concentric outcrops. 
 Plant yourself on the inner or middle formation. Notice that 
 this now underlies all the others. This also, dips toward all 
 the others, and passes under them out of sight. Then fix 
 your attention on the outcrop of the next dish. Notice that 
 this dips away from the first one the older one, first laid 
 down ; and that it dips toward the newer or overlying forma- 
 tions. And so to the uppermost or newest each newer dip- 
 ping away from all the older. 
 
 This arrangement of strata is common. The city of Cin- 
 cinnati stands on an upward bulge of Cambrian rocks. All 
 around, at the distance of some miles, may be seen the 
 outcropping edge of the Silurian System. The Silurian strata 
 overlie the Cambrian, as shown in the Table, page 73, and 
 
COURSES OF THE EARTH'S MASONRY. 77 
 
 dip away from them. Next, a few miles farther from Cin- 
 cinnati, on all sides, we come to the Devonian strata; and 
 next, the Lower Carboniferous. 
 
 Very frequently the dip is in opposite directions along a 
 line, as if an inverted nest of troughs had had their bottoms 
 sawed off. If you turn an open book so that it rests on the 
 table with the back up, then the leaves are strata ; their in- 
 clination to the table is the dip, and the two inclinations in 
 opposite directions form an anticlinal structure. If you keep 
 the leaves in the same position and turn the back of the book 
 down, the structure is synclinal. It is rather necessary to un- 
 derstand these terms, because we meet with such structures so 
 frequently, and shall have to talk about them. 
 
 Very commonly, the dishes and troughs of which I am 
 speaking are irregular. A trough, whether inverted or not, 
 may bend, and change the course of its axis. That makes it 
 more difficult to follow, especially as -nearly all the rock sur- 
 faces are concealed by Drift. Sometimes the trough is de- 
 pressed at one end; sometimes at both ends; sometimes in the 
 middle. Again, there may be an uplifting of one or both 
 ends, or of the middle. The determination of the order of 
 the strata is often much complicated by those erosions of which 
 we have talked. Suppose, for instance, we have an anticlinal 
 axis, and suppose the surface of the earth horizontal. Then 
 if a deep broad valley were worn across and through the an- 
 ticlinal series of strata, what sort of curves would be pre- 
 sented by the cut edges of the formations? Can you think 
 them out? But suppose the anticlinal strata are elevated in 
 a long ridge like a mountain, and a deep valley should be 
 cut down one side, can you picture to your imagination the 
 lines which the cut edges of the strata would trace ? I think 
 it would be well for the ingenious reader to contrive something 
 to serve as a model to illustrate these complicated arrange- 
 ments. A nest of wooden or paper dishes might be glued 
 together and sawed and grooved and carved into shapes 
 imitating the configuration of the earth's surface. Even 
 in level and undisturbed strata erosions have created some 
 
78 WALKS AND TALKS. 
 
 complications. These are easily illustrated. Glue together 
 thin board-like pieces of pine, cherry, oak, beech, mahogany, 
 apple or other woods, to represent strata. Then cut the pile 
 in various slopes and curves, and notice where the various 
 sorts of wood outcrop. This represents precisely what we ob- 
 serve in the actual arrangements of outcrops. But the Drift 
 covers so much that we often experience difficulties in finding 
 where the rocky outcrops lie. 
 
 The complications in the structural arrangements of the 
 rocks are still greater. Anticlinal dips pass off each side into 
 level strata or synclinal arrangements. A synclinal arrange- 
 ment is often along the highest region, instead of the lowest, 
 as one would expect. On the contrary, an anticlinal arrange- 
 ment is often along the bottom and sides of a valley, instead 
 of running along the crest of a mountain, as one might expect. 
 These things result from extensive erosions. Again, the dips 
 sometimes become very great even -vertical and there may 
 be difficulty in deciding which is the upper side of a stratum. 
 Worse than this, we sometimes find a pile of strata tilted so 
 far as to seem to dip in the opposite direction. Then the 
 older and lower strata in fact lie uppermost, and seem to be 
 newer. This inversion of strata sometimes occurs along the 
 Appalachians. 
 
 But there are some compensations for all this confusion. 
 The Eozoic, or crystalline rocks are lowest of all in position, 
 and when they are in sight they form a landmark from which 
 we can estimate upward. Remember, however, that the low- 
 est rocks lowest in geological position are often highest in 
 topographical position. They are often at the summits of 
 mountains, as in the Alps and the Rocky Mountains. The 
 newer strata then slope down in order along each side of the 
 mountain, and pass under the plain. 
 
 In the next place, strata are to some extent, arranged in 
 long folds, which here rise in a ridge, and there disappear un- 
 der a synclinal. Such long drawn forms are found along the 
 Laurentian hills in Canada, and along the Appalachians. 
 Here we catch sight of a general method in rock arrangements. 
 
A WALK IN THE YELLOWSTONE PARK. 79 
 
 Still again, the newest strata lie along the Sea and Gulf 
 shores, and dip down under the water. These sheets of sedi- 
 ments are undisturbed. Beneath these are generally older 
 strata which have a corresponding dip. These seaward dip- 
 ping strata are Csenozoic and Mesozoic. When we descend to 
 the Palaeozoic strata we often find them considerably folded 
 and irregular. 
 
 In general, the present positions of the strata may be ex- 
 plained as if they had been produced thus : First, the uni- 
 versal ocean deposited sediments which hardened into Eozoic 
 rocks which universally underlie. Then some portion of the 
 bottom was uplifted to daylight, and the sediments of the next, 
 or Palaeozoic, jEon were not universal. Next the uplifted 
 regions were further uplifted, and some of the Palaeozoic sedi- 
 ments appeared along the margins of the Eozoic. Then fol- 
 lowed Mesozoic sedimentation, another uplift of the same 
 regions ; then Caenozoic sedimentation and other uplifts. 
 Meanwhile the destructive work of erosion was in progress, and 
 the original shapes of the uplifted strata, already disguised by 
 many movements, were further obscured by the wearing down 
 of extensive formations, and the obliteration of some. But 
 of all this we shall catch more satisfactory glimpses hereafter. 
 
 . A. 
 
 THERMAL WATERS. 
 
 IN the north-western corner of the territory of Wyoming 
 is a tract sixty-five miles long and fifty-five miles broad which 
 has been reserved by act of Congress (March 1, 1872) as a 
 national park or reservation "dedicated and set apart as a 
 public park or pleasuring ground for the benefit and enjoy- 
 ment of the people." This was done on the recommendation 
 of the national geologist, Dr. F. V. Hayden. The tract on 
 the north extends about two miles into the territory of Mon- 
 tana, and on the west, two and a half miles into Montana and 
 Idaho. For natural scenery it is one of the most remarkable 
 
80 WALKS AND TALKS. 
 
 regions on the surface of the earth. It lies on the great con- 
 tinental divide at a mean altitude of six thousand feet, and 
 includes mountain summits rising to ten and twelve thousand 
 feet about twice the altitude of Mount Washington, and 
 covered, of course, with perpetual snow. Within the tract is 
 the Yellowstone Lake, which lies 7,427 feet above sea-level. 
 Two or three miles west of this is Two Ocean Pond, lying on 
 the water-shed. On the east, the drainage from this pond 
 passes into the Yellowstone Lake and Kiver, and thence into 
 the Missouri and the Gulf of Mexico. On the west, the same 
 pond drains into Shoshone Lake, the Snake and Columbia 
 rivers and the Pacific Ocean. The Yellowstone and Madison 
 are the chief rivers of the reservation, the first flowing west to 
 form the Missouri, and the other north to a navigable tribu- 
 tary of the same. The upper Madison is also known as the 
 Firehole river. Gardiner's river is an important tributary of 
 the Yellowstone, flowing north, and making its junction on the 
 northern boundary of the Park. Some of the loftiest moun- 
 tains of the interior overlook the Park on all sides. On the 
 east, are the two ranges of the Shoshone Sierra ; on the w r est, 
 the Gallatin Range ; on the south, the Red Mountain Range 
 and the Pitchstone Plateau; on the north, a belt of "peaks" 
 rising ten and eleven thousand feet high. These mountains, 
 like nearly the whole surface of the Park, are composed of 
 volcanic rocks. The Yellowstone, after passing two falls, re- 
 spectively 162 and 350 feet, flows through a caiion nine miles 
 long, which has been thus described: 
 
 " For a mile away, the sides are formed of slopes from 
 which rise vast battlements, turrets, pinnacles, alone or in 
 clusters, of tall conical spires; some are of basalt, some of 
 limestone [this is probably an error] ; they rise through slopes 
 part clay and part broken silicates and limestone. On this 
 mass of material nature has lavished her wealth of colors with 
 a spendthrift hand. The taller rocks of ruddy browns or 
 Pompeian red melt away in the debris from which they spring, 
 to rich yellows, fading below, to cool grays in exquisite grada- 
 tion. Here and there are rocks of a red like claret lees; 
 
A WALK IN THE YELLOWSTONE PAEK. 81 
 
 others have a basis of rich ochre, with the projections of 
 umber brown. In places, the reds are nearly of a dark 
 scarlet. Here the rocks are of a lovely French gray ; there, 
 of a delicate fawn tint, rising above to saffron, and melting to 
 snow-white below ; while in places, patches of vivid green, 
 orange or black mark the masses of moss and lichen fed by 
 the abundant spray, and forced into luxury of growth by the 
 warm streams from the numberless springs issuing from the 
 walls of the canon." Lippincott's Magazine, June, 1880, p. 699. 
 
 It is not for the scenery not even for the geology of the 
 Park, that I have led you hither. What I have noted will 
 serve to illustrate principles to be stated hereafter. I wish 
 your imaginations to be impressed by the wonderful groups 
 of geysers and hot springs scattered through the Park. I wish 
 you to make the acquaintance of some facts from which we 
 may derive important inferences bearing on internal heat. Mr. 
 A. C. Peale, one of the United States geologists, has described 
 in the Park 2,195 warm springs, and expresses the belief that 
 three thousand exist. He has also named and described 
 seventy-one geysers. A geyser is a spring which periodically 
 throws up hot water to some distance above the level of the 
 ground. 
 
 Let us take a particular geyser and note its situation and 
 the phenomena connected with its eruptions. "Old Faithful" 
 geyser is one of a group in the upper part of the valley of 
 Firehole river. The external formation is a mound or table 
 of geyserite or silicious sinter a whitish mineral composed 
 chiefly of silica and water, and deposited from the waters of 
 the geysers. The mound is one hundred and forty-five feet 
 by two hundred and fifteen at base, and twenty by fifty-four 
 feet at top. It rises about twelve feet above the surrounding 
 level, and is composed of layers of deposit arranged in a suc- 
 cession of steps that are made up of small basins. Near the 
 top these basins are beautiful, broad, shallow pools, with pink, 
 cream, white, brown and gray bottoms, in which the deep 
 azure-tinted water stands after the eruptions. The "chimney" 
 or " crater" is the top of a " basin" five feet deep, at the bot- 
 
82 WALKS AND TALKS. 
 
 torn of which is an irregular orifice, the head of the geyser 
 " tube." The eruption begins with some preliminary splashes 
 or spurts from three to a dozen or more which appear like 
 abortive attempts at eruption. These grow more powerful for 
 about four minutes when jets in rapid succession escape with 
 a roar, and soon attain the maximum height. In a few sec- 
 onds later the column subsides with occasional vigorous spurts. 
 The water eruption is followed by steam which escapes gently 
 and soon dies away, leaving the crater empty. The water is 
 thrown to a maximum height of one hundred and fifty feet. 
 
 General Sherman thus describes "Old Faithful:" "We 
 saw Old Faithful perform at intervals of sixty-two to eighty 
 minutes. So regular are its periods of activity that we could 
 foretell its movements within a few minutes. Sometimes we 
 stood near enough to feel the hot spray, and at others, we sat 
 at our camp, three hundred yards away. Each eruption was 
 similar, preceded by about five minutes of sputtering, and then 
 would arise a column of hot water, steaming and smoking, to 
 the height of one hundred and twenty-five or one hundred and 
 thirty feet, the steam going a hundred or more feet higher, 
 according to the state of the wind. The whole performance 
 lasts about five minutes, when the column of water gradually 
 sinks, and the spring resumes its normal state of rest." Re- 
 ports of Inspections, 1877, p. 36. 
 
 The "Giantess" geyser, belonging also, to a group on the 
 upper Firehole, has an inconspicuous crater, but is charac- 
 terized by magnificent eruptions. Mr. N. P. Langford writes 
 of it: "No water could be discovered, but we could dis- 
 tinctly hear it gurgling and boiling at a great distance below. 
 Suddenly it began to rise, boiling and spluttering, and send- 
 ing out huge masses of steam, causing a general stampede of 
 our company. When within about forty feet of the surface, 
 it became stationary, and we returned to look down upon it. 
 It was foaming and surging at a terrible rate, occasionally 
 emitting small jets of hot water nearly to the mouth of the 
 orifice. All at once it seemed seized with a fearful spasm, and 
 rose with incredible rapidity, hardly affording us time to flee 
 
A WALK IN THE YELLOWSTONE PARK. 83 
 
 to a safe distance, when it burst from the orifice with terrific 
 momentum, rising in a column the full size of this immense 
 aperture, to the height of sixty feet; and through and out of 
 the apex of this vast aqueous mass five or six smaller jets or 
 round columns of water, varying from six to fifteen inches in 
 diameter, were projected to the marvelous height of two hun- 
 dred and fifty feet." This eruption continued twenty min- 
 utes; and two eruptions occurred during twenty-four hours. 
 
 The numerous other geysers in their action present phe- 
 nomena essentially similar to these. The mineral deposit gen- 
 erally forms a mound, cone, or nozzle, through which the 
 water escapes. This varies greatly in diameter and height. 
 In the White Dome and White Pyramid geysers it is twenty- 
 five feet high. In the Giant geyser the cone is ten feet high 
 and rests on a platform four feet high and over three hundred 
 feet in diameter. The material is generally geyserite ; but a 
 few geysers and springs exist in which it is travertin or cal- 
 careous tufa, consisting of calcium carbonate. The Soda 
 Butte, on the east of the Yellowstone, is a conical mound 
 twenty feet high, which though now closed at the top, was 
 formerly an active geyser. It is composed of travertin, and 
 Soda Butte is a misnomer. 
 
 The thermal springs of the Park have built up mineral de- 
 posits of extremely curious and interesting character. The 
 Mammoth Hot Springs, on Gardiner's river, three miles from 
 its mouth, situated on a series of terraces, present a fine de- 
 velopment of a style of formation characteristic of hot springs 
 in various parts of the world. The waters issue at many dif- 
 ferent levels along a slope, and the calcareous deposit takes 
 the form of a pile of tubs so arranged that the overflow from 
 one at a higher level falls into another at a lower level. The 
 tubs are of various depths and diameters, and sometimes dis- 
 play lively shades of color greenish, reddish, and yellowish. 
 There are several terraces of deposits from which the water 
 has disappeared ; and the evidence is, generally, that the ther- 
 mal energy of the region is diminishing. 
 
 The phenomena of hot springs are well known in various 
 
84 WALKS AND TALKS. 
 
 parts of the world. Some of those of New Zealand present 
 close resemblances to the Mammoth Hot Springs of Gardiner's 
 river. Geysers occur also, in New Zealand ; but the most 
 celebrated is the Great Geyser of Iceland. To impart a con- 
 ception of its behavior in eruption, the following description 
 by S. Baring Gould is cited: "Five strokes under ground 
 were the signal, then an overflow, wetting every side of the 
 mound. Presently a dome of water rose in the centre of the 
 basin and fell again, immediately to be followed by a fresh 
 bell, which sprang into the air full forty feet high, accompa- 
 nied by a roaring burst of steam. Instantly, the fountain 
 began to play with the utmost violence ; a column rushed up 
 to the height of ninety or one hundred feet, against the gray 
 night sky, with mighty volume of white steam cloud rolling 
 about it, and swept off by the breeze to fall in torrents of hot 
 rain. Jets and lines of water tore their "way through the 
 cloud, or leaped high above its domed mass. The earth 
 trembled and throbbed during the explosion, then the column 
 sank, started up again, dropped once more, and seemed to be 
 sucked back into the earth." Pen and Pencil Sketches of Faroe 
 and Iceland. 
 
 No one can contemplate the phenomena of a geyser or hot 
 spring without feeling a conviction that heat is the essential 
 condition. Somewhere within the earth is a repository of heat 
 sufficient to warm, or even to boil, the water which rises to 
 the surface. Strata whose outcropping edges appear at the 
 surface, receive rain-water and convey it along the dip to un- 
 known depths. In the geyser, some concurrent conditions 
 must exist. I* is admitted that the water rises through a 
 tube, and that in its lower part a temperature exists sufficient 
 to boil water under the pressure there existing. But details 
 of the mechanism are not unanimously agreed upon. They 
 are probably somewhat as follows : Water accumulates in the 
 geyser pipe upon the steam formed in the lower part by the 
 bottom temperature. The steam, for a time, is subjected to 
 compression, and the compression increases with the continued 
 development of steam and accumulation of water. Finally, 
 
AMONG THE VOLCANOES. 85 
 
 the elastic force becomes sufficient to lift the column of water. 
 The commencement of escape now diminishes pressure, and a 
 large volume of steam is instantly formed, which causes the 
 violent eruption. The heavy thumps sometimes heard before 
 and during the action are due to collapses of steam in contact 
 with the water, and are strictly the same in principle as the 
 sharp detonations frequently heard in the steam-pipes employed 
 for warming buildings. 
 
 XV. AJVEONQ THE 
 
 INDICATIONS OF INTEKNAL FIRES. 
 
 VESUVIUS and ^Etna are the two volcanoes familiarly known 
 to classical antiquity. They offer for our observation nearly 
 all the characters with which the geological reader and student 
 should become acquainted in prosecuting his inquiries into the 
 present and past temperatures of the earth. Let us make the 
 ascent of Vesuvius, taking the usual route from Naples. 
 Driving a couple of hours down the coast to Resi'na, on the 
 site of the ancient Herculaneum, we begin the ascent either 
 on foot or on mule or horse back. For thirty minutes we fol- 
 low a rough road through vineyards. The road then turns to 
 the north and we enjoy a lovely view of the landscape and the 
 bay. Here stretch two dark streams of cold lava presenting 
 somewhat the aspect of enormous beds of enormous cinders 
 fibrous and twisted and waxy. They are the lava streams of 
 1858 and 1868. Next appears the huge lava wall of 1858. 
 In two hours from Resin a, we reach the Observatory, 2,218 
 feet above sea-level, erected in 1844 for meteorological and 
 seismic observations. Here Professor Palmieri, the celebrated 
 vulcanologist, is engaged in making the most minute studies 
 of the incidents in the history of the mountain. From this 
 station and the "Hermitage" just below, where the traveler 
 procures refreshments, the view over the black and herbless 
 lava slope is desolate beyond description. Soon the road be- 
 comes impracticable for quadrupeds. Crossing the lava flood 
 of 1871, we now reach the Atrio del Cavallo, at the foot of 
 
86 WALKS AND TALKS. 
 
 the cone. This is the valley which separates the highest and 
 principal summit of the mountain from Monte Somma, a frag- 
 ment of an ancient crater of much larger size than the modern 
 one. The height of Vesuvius varies from 3,900 to 4,300 feet. 
 Monte Somma stands 3,642 feet. The slope of the mountain 
 near the base is 10, while the active cone has a gradient of 
 29 to 30. Monte Somma rises almost perpendicularly from 
 the Atrio del Cavallo, while on the opposite side, it slopes to 
 the plain at an angle of three degrees. 
 
 The entire mountain, so far as can be seen, is a vast pile 
 of lava, lapilli (stones) sand and ashes (powder-like lava) 
 resulting from a long succession of eruptions. The molten 
 mineral matter thrown out is lava. It escapes from the regu- 
 lar crater or bursts out through some new fissure near the 
 summit, around which the erupted materials may accumulate 
 and form a subsidiary crater. The molten lava has a tem- 
 perature above 2000 Fah. Often vapor of water escapes with 
 the lava, and throws the molten mineral up with such violence 
 as to break it into fragments, the larger of which are known 
 as lapilli and scoriae, while the minuter fragments constitute 
 volcanic sand and ashes. The vapors rise to a height of about 
 ten thousand feet, and spread over the mountain like a vast 
 umbrella or Cedar of Lebanon. Indeed, the height sometimes 
 attained by this enormous canopy of vapor and ashes has been 
 shown by measurements to reach twenty-three thousand to 
 twenty-six thousand feet. Enormous quantities of ashes borne 
 upward with the vapor, give the cloud a dark and angry 
 appearance, and its frowning aspect is confirmed by the flashes 
 of lightnings which dart through it. By night the vivid re- 
 flection of the light thrown upward from the crater gives the 
 appearance of terrific flames roaring from the summit of a 
 burning mountain. But no proper combustion exists. Often 
 the condensation of the vapor results in rain which descends 
 in a torrent. The ashes mingled with water convert the storm 
 into a deluge of mud. This rushes down the mountain with 
 destructive effects, and in several instances, whole villages and 
 even cities have been buried in mud. 
 
AMONG THE VOLCANOES. 87 
 
 A moderate disturbance of the mountain is characterized 
 by the ejection of vapors and stones, accompanied by a roar, 
 resembling that of distant artillery. More serious eruptions 
 are accompanied by loud subterranean noises, earthquakes, 
 and vivid electric phenomena. 
 
 History records a large number of Vesuvian eruptions. 
 According to Strabo, Vesuvius was once covered by beautiful 
 meadows, except over the summit, which was level and sterile. 
 "It has" he says, "an appearance like ashes, and shows rug- 
 ged rocks of sooty consistency and color, as if they had been 
 consumed by fire." At the same period the theater of vol- 
 canic activity was a few miles toward the west. Ischia, Pro- 
 cida, the Solfatara and the Monte Nuovo were then active 
 craters. About A. D. 63, the volcanic nature of Vesuvius 
 manifested itself; and in 79 occurred the terrific eruption 
 which overwhelmed Pompeii, Herculaneum, Stabise, and other 
 villages in a deluge of ashes and mud. In the eruption of 
 1631, heavy stones were thrown to the distance of 15 miles. 
 One which fell at the village of Somma had a weight of 
 fifteen tons. The earth was convulsed by a violent earth- 
 quake, and seven streams of lava poured from the summit, 
 overwhelming Bosco, Torre dell' Annunciata, Torre del Greco, 
 Kesina and Portici. Three thousand persons perished on the 
 occasion. In 1779 a vast number of red-hot stones were 
 hurled to a height of two thousand feet. In April, 1872, after 
 months of threatening, the lava burst forth on every side on 
 the north-east, south-west, and more particularly at the Atrio 
 del Cavallo, from which a huge stream issued with such sud- 
 denness as to overtake and destroy twenty persons out of a 
 crowd of spectators gathered to watch the spectacle. The tor- 
 rent descended to Massa and St. Sebastiano, passing beneath 
 these villages, which it partially destroyed, in a molten stream 
 3,000 feet wide and 20 feet deep. At the same time, amidst 
 terrific thundering, the crater hurled forth immense volumes 
 of smoke, mingled with red-hot stones and lava, to a height 
 of 40,000 feet. 
 
 Mt. ^Etna is altogether a more majestic structure. It has 
 
88 WALKS AND TALKS. 
 
 a circumference at base of one hundred miles. It rises 10,840 
 feet above sea-level, and 3,000 feet above the forest-limit. 
 The highest cone is a black and silent waste. The whole 
 mountain, from top to bottom, is a series of frozen lava- 
 sheets piled one above another. Some conception of the age 
 of the mountain may be formed from the fact that JEtna has 
 been known from the earliest ages as a volcanic mountain, 
 and eruptions have occurred, on an average, once in ten years, 
 yet, within the historic period its bulk and altitude have not 
 increased to a perceptible extent. The eruptions of ^Etna are 
 attended by circumstances similar to those of Vesuvius. The 
 lava, however, does not escape, in modern times, from the 
 summit crater, but breaks through the wall at some distance 
 below. In 1669, the Monti Rossi, so-called, were formed, and 
 27,000 persons were deprived of all shelter, and many lives 
 were lost in the descending streams* of lava. In 1693, an 
 eruption was accompanied by a fearful earthquake which par- 
 tially or totally destroyed forty towns and caused a loss of 
 sixty to one hundred thousand lives. 
 
 One of the greatest eruptions of modern times occurred in 
 1865. After violent premonitory symptoms two years pre- 
 viously, when the loftiest cone of the volcano opened on the 
 side and emitted a large stream of lava, the wall of the 
 mountain yielded to the pressure of its molten contents. 
 Some subterranean roaring was first heard ; slight agitations 
 affected the whole eastern part of Sicily, and the ground was 
 rent open for a mile and a half to the north of Monte Fru- 
 mento, one of the secondary cones which rise on the slope of 
 ^Etna. This vomited lava for a few hours, when, seeming to 
 be obstructed, fresh outbursts occurred a little lower down, 
 and six cones of ejection were built up. These and smaller 
 ones blended together in an elevation of nearly 300 feet. Soon 
 the two upper craters hurled forth only lumps of stone and 
 ashes, while the lower poured forth lava. Then followed the 
 diversified phenomena of a prolonged eruption, which, however 
 interesting, we have not space to describe. Of the volume of 
 lava something may be said. 
 
AMONG THE VOLCANOES. 89 
 
 During the first six days, the quantity of lava issuing 
 from the fissure of Monte Frumento was estimated at 117 cu- 
 bic yards a second. In the vicinity of the outlet, the speed 
 of the current was not less than twenty feet a minute ; but 
 lower down the velocity was diminished. On the second of 
 February, the principal current had traveled three miles. It 
 was from 900 to 1,600 feet wide and 49 feet deep. Here it 
 plunged like a cataract into a deep gorge. "It was a mag- 
 nificent spectacle, especially during the night, to see this sheet 
 of molten matter dazzling red like liquid iron, making its way 
 in a thin layer, from the heaps of brown scoriae which had 
 gradually accumulated above ; then carrying with it the more 
 solid lumps which dashed one against the other with a metallic 
 noise, it fell over into the ravine only to rebound in stars of 
 fire." In a few days, the ravine was filled and the lava stood 
 160 feet deep. From this the flow continued east toward 
 Mascali, filling to its brink, on the way, the winding gorge of 
 the dried up rivulet. By the middle of February, the river 
 of fire was more than six miles long, and its flow was more 
 and more slackened by incasement in a crust of cooled ma- 
 terial. Through this, it continually burst, in front and on the 
 sides, and new spurts darted off for short distances in various 
 directions, giving to the solidified stream an aspect character- 
 istically rough. Suddenly one of the outbursts far up the 
 stream, resulted in a new river, which flowed toward the plains 
 of Lingua grossa, swallowing up thousands of trees. The de- 
 structive action was not much longer continued, but months 
 after the commencement of the eruption, the molten fluid 
 within the incrusted river continued to burst forth in slowly 
 advancing and overlapping outflows, leaving an exterior black 
 and rough beyond description. 
 
 This eruption may serve to illustrate the volume of molten 
 lava sometimes emitted from a volcano. Perhaps a more 
 striking example of volume is furnished by the volcano of 
 Coseguina, a hillock about 500 feet high on a promontory to 
 the south of the Bay of Fonseca in Central America. The 
 ashes thrown into the upper atmosphere spread out in a dark 
 
 8 
 
90 WALKS AND TALKS. 
 
 canopy several hundred miles in width. It covered the plains 
 for a distance of twenty-five miles, with a layer of dust six- 
 teen feet thick. The headland was advanced 787 feet into 
 the bay. Two new islands were formed from the ashes and 
 stones. The wind carried the dust westward more than forty 
 degrees of longitude, and a layer of pumice was formed at that 
 distance which vessels penetrated with difficulty. On the 
 east, the fall of ashes extended to Jamaica, 800 miles. The 
 area covered by the fall was one and a half million square 
 miles ; and the total volume of matter which escaped was not 
 less than 65J billions of cubic yards. The sound of the ex- 
 plosion was heard at Bogota, 1,025 miles distant. Impenetra- 
 ble darkness reigned for forty-three hours throughout the re- 
 gion of the eruption. 
 
 The amount of lava from Kilau-e'-a in 1840 exceeded 
 six billion five hundred and fifty million cubic yards. That 
 from Mauna Loa, in 1835, flowed seventy-six miles from the 
 crater. The volcano of Skaptar Jokul, in Iceland, was cleft 
 asunder in 1783, and gave vent to two rivers of fire, each of 
 which filled up a valley; one attained a length of fifty miles, 
 with a breadth of fifteen miles; the other was of less dimen- 
 sions, but the depth of the mass was in some places as much 
 as four hundred and ninety-two feet. The whole volume of 
 lava erupted on this occasion was not less than six hundred 
 and fifty-five billions of cubic yards a volume equivalent to 
 that of the whole mass of Mont Blanc. 
 
 Many thrilling narratives of volcanic violence might be 
 cited ; but these must serve as examples. They demonstrate 
 the existence of enormous reservoirs of molten rock within 
 the earth, and the exertion of such inconceivable forces as 
 suffice to burst mountains, to hurl rock-fragments a mile into 
 the atmosphere ; to blow into atoms, while escaping with 
 steam and gases, sufficient matter to bury thousands of square 
 miles in ashes. It appears that isolated volcanic cones, like 
 Vesuvius, jEtna, and Shasta, are composed generally of piles 
 of ejected materials, inaugurated by the escape of matter 
 through an initial fissure. The volcanic cone is hollow above, 
 
FROZEN SEAS OF LAVA. 91 
 
 with a pipe leading down into the earth. Through this the 
 lava rises into the cavity. When the strains have sufficiently 
 accumulated, the lava is forced above its usual level some- 
 times overflowing the lips pf the crater; sometimes bursting 
 the walls of the mountain, thinned by melting from within. 
 Sometimes, also, the walls by internal fusion become so much 
 weakened that the whole summit falls in, leaving an enor- 
 mous open chasm. Over this a solid crust forms by exposure. 
 Then, in subsequent ages, this is pierced by a new rupture, 
 around which a new, and smaller, cone is built up, with the 
 broken margin of the older one still more or less perfectly 
 preserved. So, during the eruption of 79, the crater of Ve- 
 suvius collapsed, and the present crater has since grown up, 
 leaving still on the north a vast rampart, Somma, showing 
 where the line of rupture of the ancient cone was traced. 
 
 XVI. KRONEN SEAS OR 
 
 ANCIENT LAVAS. 
 
 THE spectacle of a volcano in a state of active eruption is 
 a terrific demonstration of the forces of fire imprisoned within 
 the earth, and escaping to our view only when their accumu- 
 lated strength exceeds that of the restraints in which they are 
 held. These are activities of the present ages of the world, 
 and proofs of intense heat now existing within the cool ex- 
 terior. Geology brings to our notice the records of still 
 vaster and more terrific operations of intense heat. Vast as 
 are the volumes of modern eruptions, they are slight com- 
 pared with eruptions of former geologic ages. The limited 
 amount of matter poured forth in modern times cools near the 
 place of escape, and seldom flows to the distance of ten miles. 
 It accumulates, therefore, around the vent, and builds up a 
 volcanic cone.^ In earlier times the molten lava issued in such 
 quantity as to retain its liquid state sufficiently long to flow 
 away sometimes a hundred miles or more, and overspread 
 with a sea of fire regions as broad as States. The modern 
 
92 WALKS AND TALKS. 
 
 volcano exhibits, perhaps, a greater explosive energy than the 
 ancient one, and hence it may disperse greater volumes of 
 ashes ; yet some of the ancient volcanoes, near the beginning 
 of modern geological history, have ejected vastly greater quan- 
 tities of ashes than have been known to escape during any 
 eruption of historic times. Let us make the acquaintance of 
 some of the most remarkable of lava-covered areas. 
 
 Let us turn, first, to what is probably the most extraordi- 
 nary outflow of lava lying on the earth's surface. A concise, 
 but comprehensive description has been furnished by Pro- 
 fessor Joseph Leconte: "Commencing in middle California as 
 separate streams, in northern California it becomes a flood 
 flowing over and completely mantling the smaller inequalities, 
 and flowing around the greater inequalities of surface ; while 
 in northern Oregon and Washington it becomes an absolutely 
 universal flood, beneath which the whole original face of the 
 country, with its hills and dales, mountains and valleys, lies 
 buried several thousand feet. It covers the greater portion 
 of northern California and northwestern Nevada, nearly the 
 whole of Oregon, Washington, and Idaho, and runs far into 
 Montana and British Columbia on the north. Its eastern and 
 southern limits are not well known, but its extent can not be 
 less than one hundred and fifty thousand to two hundred 
 thousand square miles, with a thickness of three thousand to 
 four thousand feet in its thickest part, where cut through by 
 the Columbia River. In another place, at least seventy miles 
 distant, where cut into twenty-five hundred feet deep by the 
 Des Chutes River, at least thirty successive sheets may be 
 counted." 
 
 The Columbia has cut through the entire breadth and 
 depth of the Cascade range, down to within one hundred feet 
 of sea-level. Here is a canon one hundred miles long, with 
 the summits of the range rising twenty-five hundred to thirty- 
 eight hundred feet above the river surface. The entire walls 
 of the canon are composed of ancient lava. When we reflect 
 that the peaks of the Cascade range are simply results of 
 erosion, we can well believe that the highest summits were 
 
FKOZEN SEAS OF LAVA. 93 
 
 originally not less than four thousand feet above the base of 
 this astounding lava-deposit. 
 
 This vast and ponderous sheet of lava appears to have 
 flowed through fissures from the Cascade Mountains, and nat- 
 urally to have accumulated to greatest thickness along that 
 range. The sheet extends across eastern Oregon to the Blue 
 Mountains. From this range, also, other, but less copious, 
 lava streams were poured forth. 
 
 The chain of volcanic outbursts continued southward into 
 the Sierra Nevada. The lava vents here were more local and 
 isolated. The lava, though enormous in quantity, was less 
 than in Oregon, and overspread the surface less generally. 
 Under these circumstances, great volcanic cones were built 
 up such as Lassen, Shasta, Hood, and Ranier. From 
 Lassen's Peak the sheets of lava form a regular slope to the 
 Sacramento river. Through this the streams have cut their 
 channels five hundred to eight hundred feet deep. 
 
 Nearly all the so-called Basin Ranges lying eastward of 
 the Sierra Nevada, through Utah and parts of California and 
 Arizona, are composed, at least in part, of ancient lavas. 
 Through the Plateau Region, farther east, lavas are equally 
 abundant. In the Sevier Basin, according to Gilbert, the 
 great Sevier fault, or break, through the rocks, exposes a 
 maximum thickness of two thousand feet. South of the Col- 
 orado is a much larger lava-basin, spreading several broad 
 lobes over into New Mexico, the most easterly of which, 
 reaches nearly to the Rio Grande. Its extreme limits are 
 three hundred and twenty-five miles apart. It includes the 
 San Francisco, Mogollon, and Sierra Blanca mountains. This 
 outflow proceeded from a large number of vents. In San 
 Francisco Mpuntain we have a pyramid of compact lava 
 nearly five thousand feet high, with slopes of ten to twenty 
 degrees. 
 
 The examples cited are sufficient to impress the imagina- 
 tion and enable us to appreciate the magnitude of the work 
 of heat in the geological aeon not long antecedent to the dawn 
 of modern times. We mark the Tertiary, and especially the 
 
94 WALKS AND TALKS. 
 
 later Tertiary, ages as signalized in the history of the world 
 by outflows of molten lava primarily from fissures, but sec- 
 ondarily building up small and moderate sized cones in great 
 abundance, and not a few stupendous mountain piles reaching 
 to eighteen thousand feet. 
 
 In remote geologic ages lava eruptions were of frequent 
 occurrence but less frequent and less copious than in later 
 ages. During the Triassic Age (see Table, p. 73) many erup- 
 tions of lava occurred, both in Europe and America. The 
 Palisades of the Hudson; the cliffs of Meriden, Connecticut, 
 and East and West Rock, New Haven, are ancient lavas of 
 this age. Much farther back in geological history, in Cambrian 
 time, or as some think before Cambrian time, vast and repeated 
 outflows of lava took place which remain to-day uplifted in 
 Keweenaw Point and He Roy ale. The native copper is 
 found imbedded in these ancient lavas. 
 
 A fissure filled with rock-material solidified from a state of 
 fusion, is a dyke. Sometimes the formation containing the 
 dyke is more friable than the lava, and weathers away more 
 rapidly. The dyke then projects above the surface like a 
 vertical wall. Certain varieties of lava called basalt possess 
 the peculiar property of assuming a columnar structure while 
 cooling. The longer axes of the columns are ranged at right 
 angles with the cooling surfaces. Thus, when the basalt cools 
 in a fissure, the columns lie transversely from wall to wall. In 
 most cases, the columns are vertical. This is thought some- 
 times to result from cooling under the sea ; but probably when 
 a sheet of basalt rests on the surface of the earth, the atmos- 
 phere above and the earth below are cooling surfaces of the 
 requisite efficiency to develop vertical columnar structure. 
 The columnar structure induced to an imperfect extent, in 
 basaltic rocks of He Royale may be conceived as produced in 
 the bottom of the sea; but the columnar structure in the 
 canon of the Columbia must have been acquired upon the 
 land. The columns, in some cases, rest with their ends 
 directly on a bed of pebbles and sand not over a hundred 
 feet thick, and bearing the evidences of torrential action 
 
FROZEN SEAS OP LAVA. 95 
 
 therefore a shallow- water deposit, while the columnar basalt is 
 three thousand five hundred feet thick. High cliffs of basaltic 
 columns, like those exposed on the Hudson and Columbia 
 rivers are often called palisades. 
 
 \ In some cases the uprising lavas have not been able to 
 find their way to the surface. Either the fissures in which 
 they started, from some unknown depth, never extended to 
 the surface, or the streams lost their way and found them- 
 selves pent in the strata, and crowded in every direction in 
 search of relief. In such case the lavas have sometimes in- 
 sinuated themselves laterally between the strata to such ex- 
 tent as to separate the strata by a considerable interval, with- 
 out being able to escape to the surface. The result is, a dome- 
 like elevation of the surface, forming a peculiar type of mount- 
 ains called laccolites named and first described by Mr. G. K. 
 Gilbert. In many cases, the arched strata become much fis- 
 sured, and the lava sheets communicate quite freely with each 
 other. Such laccolites exposed to the processes of erosion reveal 
 the constitution of the interior. This subject is fully illus- 
 trated by Mr. Gilbert in his memoir on the Henry Mountains 
 in eastern Utah. 
 
 River erosions of vast lava-sheets have resulted in many 
 striking forms. As the most extensive sheets are the result 
 of late geological action, they generally rest on incoherent 
 materials gravel and sand, as in Oregon and California. 
 When the erosions of the streams have cut through the lava, 
 and for some distance into the gravel, the less coherent nature 
 of the latter causes an undermining of the lava-sheet. It thus 
 projects like a table-top, beyond the gravel. When the ero- 
 sion cuts the lava-sheet along parallel lines, it gives rise to 
 the forms known as "table mountains." These are common 
 in the volcanic region of central France; and especially so in 
 eastern California. In Butte county, the ancient drainage 
 wore channels stretching westward from the upland of the 
 Sierra. These were subsequently filled by outflows of lava. 
 Then in modern times, a change of levels established drainage 
 from north to south. The modern streams, therefore, have 
 
96 WALKS AND TALKS. 
 
 cut channels across the ancient ones, and lava-topped intervals 
 remain. These are table mountains. Further south, in Tuo- 
 lumne county, the ancient and the modern drainage both 
 moved from north to south. The aucient channels, therefore, 
 stretched north and south, and the lava-sheets which filled 
 them stretched from north to south. The modern water- 
 courses have shunned the hard lava, and have dug their chan- 
 nels alongside of the lava, in less consolidated materials- 
 gravels or slates. These positions were formerly the elevated 
 banks of the streams. Thus, the undisturbed, elongated lava- 
 sheets, which rested on the bottoms of the ancient channels, 
 now rest on elongated ridges. The ancient bottoms are be- 
 neath these tables. Over the ancient bottoms were distrib- 
 uted the auriferous gravels from the mountains ; and here they 
 are still found. They are the "deep placers;" and are ex- 
 plored by drifting in from the sides. The beds of the modern 
 streams, strewn with auriferous sands from the same sources 
 form the so-called "shallow placers." 
 
 - XVII. I M PRISON ED HEDA.T. 
 INTERNAL CONDITION OP THE EARTH. 
 
 IT is a startling circumstance to see warm water issue from 
 a hole bored in the rocks. The common impression is that 
 deep waters are cooler than the average temperature at the 
 surface. A well of this sort is styled Artesian; and you will 
 understand that the water is forced up by pressure of other 
 water standing somewhere, at a higher level, and freely com- 
 municating with this. You have learned, for instance (Talk 
 XIII), that strata often dip down from their place of outcrop 
 to a great depth into the earth. Suppose a porous formation, 
 like a sandstone, thus goes down from the surface ; the rain 
 which falls on its outcrop must soak into the rock and saturate 
 it. This is then a water-bearing stratum. In descending ob- 
 liquely it passes under many places ; and if a hole should be 
 bored from the surface to this stratum, the water would rise 
 
IMPRISONED HEAT. 97 
 
 into it to the height of the place of outcrop. If the place of 
 boring is lower than the outcrop, the water will rise above the 
 surface. The water comes up with nearly the temperature 
 acquired at the bottom of the well. 
 
 The sun's warmth penetrates daily but a foot or two in 
 summer; and at night, much of this is lost by radiation. 
 Not all, however, for the deeper warmth continues to descend ; 
 and next day's excess of warmth follows this. Thus the sum- 
 mer heat accumulates, and continues to descend. It grows 
 less and less, however, and at fifty feet, can no longer be 
 discerned. The winter's cold also penetrates slowly, and 
 diminishing in intensity at every foot, ceases to influence the 
 temperature at the depth of about fifty feet. At this depth 
 then, the temperature is constant the year round. The depth 
 of constant temperature varies, however, with the nature of 
 the climate. If the surface fluctuations are excessively great, 
 you can understand that the contrasts must be felt at a greater 
 depth. In Minnesota, therefore, the depth of uniform tem- 
 perature would be greater than fifty feet. In Florida, how- 
 ever, where the climatic extremes are much less, the depth of 
 uniform temperature would be less than fifty feet. The uni- 
 form temperature under any region must be about the same 
 as the mean annual temperature at the surface. 
 
 The heat of midsummer and the cold of midwinter pene- 
 trate the earth at the rate of about one foot per week. Hence 
 the cold of January 1st is felt at a depth of twenty-five feet 
 about July 1st ; and so of the cold or heat of any other date. 
 At twenty-five feet the temperature of water is higher in 
 winter and lower in summer. So the popular opinion about 
 certain wells is not entirely unfounded. 
 
 If, however, we employ means to ascertain the tempera- 
 ture at depths below the plane of constant temperature, we 
 find it regularly increasing as we descend. We do not find 
 the rate of increase exactly the same at different localities, 
 but the average is about one degree (Fahrenheit) for every 
 fifty or sixty feet of descent. The Artesian well at Charles- 
 ton, South Carolina, is 1,250 feet deep, and the bottom 
 
 9 
 
98 WALKS AND TALKS. 
 
 temperature is 87. As the mean surface temperature is 66, 
 and the depth of uniform temperature may be assumed at 50 
 feet, the increase is at the rate of 57 feet for one degree. At 
 Louisville, Kentucky, is an Artesian well 2,086 feet deep, 
 with a bottom temperature of 86 J. As the surface tempera- 
 ture is 55^, the rate of increase is one degree for every 66 
 feet. The Belcher well at St. Louis with a depth of 2,199 
 feet, has a bottom temperature of 73. 4. The surface tem- 
 perature being 55, the indicated rate of increase is one degree 
 for 116 feet. This is exceptional. At Columbus, Ohio, an 
 Artesian well 2,775J feet deep gives a bottom temperature of 
 91 with a surface mean of 52. This implies a rate of in- 
 crease of one degree for every 77 feet. Again, the well at 
 the Insane Asylum, St. Louis, is 3,843^ feet deep and affords 
 water at 105, giving a rate of increase of one degree for 
 76 feet. 
 
 In deep mines, the temperature becomes intolerable, and 
 measures have to be adopted for the introduction of fresh air 
 from the surface. In the deep workings on the celebrated 
 " Comstock Lode," the temperature of the water at 2,000 feet 
 is 130. The water which filled the Savage and Hale and 
 Norcross mines for two years, had a temperature of 157. At 
 3,080 feet, the temperature is 170. To cool the air suffi- 
 ciently for the endurance of the miners, over thirty tons of 
 ice were consumed daily. [See further, Talk XXI.] 
 
 Tunnels through mountains generally attain oppressive 
 temperatures. The Mont Cenis Tunnel through the Alps, 
 between Turin and Chambery, lies 4, 093 feet below the surface 
 of the Pass, or 5,251 feet below the summit of Mt. Frejus, 
 and is eight miles in length. The rise of temperature discov- 
 ered in the rocks is about fifty degrees. 
 
 Assuming the rate of increase to be one degree for 60 feet 
 of descent, we should obtain, in the latitude of New York, 
 heat enough to boil water at a depth of about 9,000 feet. At 
 the depth of 50 miles, the temperature would be 4,600, 
 which is far above the melting temperature of ordinary min- 
 eral substances. In this method of reasoning we find an easy 
 
IMPRISONED HEAT. 99 
 
 explanation of the temperature of deep waters, and of the 
 molten condition of rocky matter erupted from volcanoes. But 
 we know that boiling and melting points, under the enormous 
 pressure experienced within the earth, are materially higher 
 than at the surface. There is much reason also, to argue, on 
 theoretical grounds, that the rate of increase of temperature 
 continually diminishes at any considerable depths. But, though 
 the depth may be quite uncertain at which a rock-melting 
 temperature would be reached, we have the demonstration 
 that such temperature exists at some depth. 
 
 Movements of temperature beneath the earth's surface are 
 slow. Many instances are known of permanent ice preserved 
 in caverns. At Brandon, Vermont, permanent frozen gravel 
 exists at a depth of sixteen feet. In the Caucasus, masses of 
 ice lie buried permanently in the moraines, one of which is 
 1,500 feet distant from any glacier, and others are a mile be- 
 low the termination of the glacier. In Siberia and in northern 
 America, the earth remains permanently frozen at a depth of 
 two or three feet. At Yakutsk, in eastern Siberia, the earth 
 is frozen to a depth of 700 feet. As these and other occur- 
 rences of permanent ice are not attributable to any climatic 
 influences now existing, they must be the records and evidences 
 of more rigorous climates in the past. In other words, the 
 climate of the present is still contending with temperatures 
 whose effects are lingering in protected situations long after 
 the climates have become ameliorated. It has been demon- 
 strated that an ice-cap resting several thousand years over any 
 considerable portion of the surface, would so reduce the sub- 
 jacent temperature of the earth that for many centuries after 
 the disappearance of the ice, a decrease of temperature would 
 be discovered in penetrating downward. Even centuries later, 
 so much cold would still remain within the earth, that the rate 
 of increase of temperature would be less than if the ice-cap 
 had not existed; and after 3,600 years, that rate would be 
 only half the normal rate. 
 
 Masses of lava are singularly poor conductors of heat. A 
 lava stream has been found still burning a century after its 
 
100 WALKS AND TALKS. 
 
 eruption. Some years ago a bed of ice was discovered on the 
 slope of JEtna, buried beneath a stream of lava ; and from this 
 the city of Catania has since obtained supplies of ice. On 
 Tierra del Fuego ice and lava are found interstratified for a 
 great depth each winter's snow being covered by a new lava- 
 sheet. In 1860 the crater of the mountain Kutlagaya, in Ice- 
 land, hurled out simultaneously into the air lumps of lava 
 and of ice, all intermingled together. 
 
 These are interesting facts, but I propose for them no other 
 use at present than to show some possible reasons why the rate 
 of increase is unequal at different localities or different depths. 
 We know that some regions have been overlaid by sheets of 
 snow and ice. We have also discovered reasons for believing 
 that our northern States, as far as the bowlders are distributed, 
 were covered by continental glaciers during a geological 
 period. If this was so, it may be that their cooling influence 
 is still left within the earth ; and if it is, the rate of increase 
 of temperature as observed is lower than it would be under 
 normal conditions. A more rapid rate of increase implies a 
 thinner crust of solid matter. But, while these considerations 
 must not be forgotten, it must be confessed that most of the 
 questions concerning internal heat are still imperfectly un- 
 derstood. 
 
 Though we are certain intense internal heat exists, we 
 neither know at what depth it exists, at what ratio it increases, 
 nor what is its cause or source. Nor do we know whether the 
 deep interior is in a solid or a liquid state. 
 
 As to the cause of the heat, two principal theories are held. 
 The first conceives the internal heat to be the residual heat of 
 a cooling and once molten globe. (Talks, XXXVII and 
 XXXVIII). The earth is evidently cooling. The records of 
 past volcanic action prove that heat has escaped in enormous 
 quantities from the interior. Thousands of cubic miles of 
 molten lava now solidified over the surface, imply some reduc- 
 tion of the earth's temperature, and the problem is one which 
 might be solved. The traces of former intense action at the 
 surface are retained also in enormous rock formations which 
 
IMPEISONED HEAT. 101 
 
 have not been fused and reduced to lava, but have been soft- 
 ened and .vitrified, and afterward cooled. Then the daily radi- 
 ation of heat from the earth exceeds the amount, received from 
 the sun. If the earth is cooling, and has foi; geik^gic periods 
 been cooling, it is not difficult to admit that, some former tem- 
 perature was high enough to reduce it to. a, molten ^aiiitJGisv. 
 If that condition existed, the process of cooling would result 
 in a film over the exterior, which would be the primitive or 
 fire-formed crust, on which the first ocean descended, and the 
 first sediments accumulated, while the protected interior re- 
 tained a higher temperature. The fusing temperature now 
 existing within may be but the residuum of primitive heat left 
 after so long a process of cooling. This is one view. 
 
 Again, it has been contended that the internal heat results 
 (at least in part) from crushing and friction in the crust, pro- 
 duced by motions and pressures exerted. Mallet showed that 
 the heat generated in crushing small cubes of granite might 
 become sufficient to cause fusion. We know, also, that the 
 cohesion of no substance is adequate to withstand all assigna- 
 ble pressures. No rock has the requisite rigidity to resist the 
 crushing weight of a mountain twenty miles high. Whatever 
 movements may take place in the earth's crust, involve masses 
 so great and forces so enormous that the resistances of ordinary 
 matter are inconsiderable. The most solid rocks are essentially 
 fluid or viscid. Now, such movements must necessarily result 
 from two causes : First, a slow shrinkage of the earth through 
 loss of heat ; secondly, the attractions of the sun and moon, 
 which cause tidal protuberances on the surface of the earth, 
 however rigid it may be ; and these, continually shifting their 
 positions, as the oceanic tides do, result in daily motions ade- 
 quate to develop a large amount of frictional heat. 
 
 But, whatever the cause of the internal heat existing, we 
 can not demonstrate that the whole interior is molten ; nor that 
 the earth is solid to the core ; nor that we have a solid core and 
 a solid crust, with an irregular zone between, in which the 
 matter is molten, or, at least, in a plastic state. We have 
 many facts; we are building our theories cautiously, and in the 
 
102 WALKS AND TALKS. 
 
 meantime we must all hold tightly to the facts and loosely to 
 the theories. The learner must here content himself with the 
 uncertamty r acknowledged by his masters. 
 
 * -V* V ' '</ 
 
 !xVlil! THE UNSTABLE 
 
 PHENOMENA AND CAUSES OF EARTHQUAKES. 
 
 WHEN men feel the earth beneath their feet growing un- 
 stable, the most paralyzing sense of insecurity seizes them. The 
 ground supports every thing; to the ground man intrusts his 
 .most elaborate and substantial structures, and when it fails 
 him the dismay is complete. Yet the solid earth has not only 
 been shaken by throes which have ingulfed cities and popula- 
 tions and mountains, but there is scarcely a moment when its 
 movements or its tremblings may not be felt by the delicate 
 means of research employed by modern science. The stability 
 of the solid earth is instability itself. 
 
 The destructive shock lasts but a few minutes, or even 
 seconds. The successive vibrations which devastated Calabria 
 in 1783 were felt during barely two minutes. On the occa- 
 sion of the destruction of the city of Lisbon, in 1755 and the 
 loss of 60,000 lives, it was the first shock, lasting five or six 
 seconds, which caused the greatest damage. As to extent of 
 damage, Sicily, in 1693, and Calabria, in 1783, have been 
 among the greatest sufferers. Each, according to best esti- 
 mates, lost a hundred thousand lives. In Syria, Japan, and 
 the Sunda Archipelago, earthquakes are reported to have been 
 attended by still greater fatalities. In the year 526, more 
 than 200,000 people met with death at Antioch and the ad- 
 jacent towns. The volcanic eruption of Kra-kat'o-a, in 
 August, 1883, was attended by a sea-wave and earthquake 
 which, according to reports, caused the death of twenty thou- 
 sand persons. 
 
 The motions which constitute an earthquake are various. 
 Sometimes they are vertical, either slow or rapid. More gen- 
 erally they are horizontal. In such case, they consist mostly 
 
THE UNSTABLE LAND. 103 
 
 of short, sudden vibrations which travel through the earth at 
 the rate of one or two thousand feet a second. The rate of 
 transmission varies with the intensity of the shock and the 
 nature of the rock materials. When mines of powder were ex- 
 ploded near Holyhead, in Wales, the waves of disturbance 
 were propagated through wet sand at the rate of 951 feet a 
 second ; through friable granite 1,283 feet, and through com- 
 pact granite 1,640 feet a second. Mr. Mallet calculated that 
 during the earthquake of Calabria in 1857, the waves 
 traveled through the earth at the rate of 820 feet a second. 
 
 It appears thus, that the transmission of the waves of 
 disturbance is favored by the solidity of the medium. Hence 
 we discover the explanation of a fact observed two thousand 
 years ago by the Greeks and Romans, that caverns, wells, and 
 quarries retard the progress of the disturbance and thus pro- 
 tect edifices built in their vicinity. 
 
 The surface movement of earthquake waves is radially 
 from a center. The cause of the disturbance must be re- 
 garded as acting with greatest violence at the center, while 
 the effects gradually die out, as the distance from the center 
 increases. But the distances to which the effects are trans- 
 mitted are not equal in different directions ; and this fact is, 
 undoubtedly, attributable to the unequal distribution of the 
 rocks. Generally, the disturbance should be farther felt in 
 the direction of the strike of strata, than in a direction, 
 across the strata; since in the latter direction, the waves have 
 to cross all the interruptions which characterize the strati- 
 fied condition. So, if on one side of an earthquake center, 
 the country is granitic, and in the opposite, is underlaid by 
 Tertiary clays and sands, the granitic region will be most 
 widely and most severely shaken. It is not supposable that 
 the actual center of an earthquake disturbance is at the sur- 
 face. It must exist at some considerable depth beneath the 
 surface. Careful study of the directions indicated by the effects 
 produced, have led not only to the determination of a radial 
 progress over the surface, but to a center of disturbance, in 
 each case, some miles beneath the surface. According to 
 
104 WALKS AND TALKS. 
 
 Mallet, the center of disturbance of the Calabrian earthquake 
 of 1857 was seven to eight miles below sea-level. From this 
 point, the waves traveled in every direction, assuming posi- 
 tions like the concentric shells of successively larger spheres. 
 Dr. Oldham found the focus of the great Cachar earthquake 
 of 1869 in India, to be considerably deeper. 
 
 It has been a common opinion, from ancient times, that 
 earthquakes are sometimes characterized by vortical or twist- 
 ing motions. The latest investigations, however, do not sus- 
 tain this view. Every position assumed by objects moved can 
 be explained by motions of a rectilinear, vibratory character. 
 
 Sounds often accompany earthquakes, even when not coin- 
 cident with volcanic eruptions. Sometimes they resemble 
 explosions as of distant artillery; more frequently it is a 
 rumbling sound as of heavy vehicles moving over a city 
 pavement. I have myself experienced but one noteworthy 
 earthquake ; and that happened in Michigan and neigboring 
 regions on the 19th of September, 1884. It lasted about ten 
 seconds. The floor on which I rested was very perceptibly 
 vibrated, and a rumbling sound was extremely audible, like 
 that of a train of cars, with the beats quite rhythmical. 
 
 Among the effects of earthquakes, though of a secondary 
 character, are the drying up of springs, the sudden increase 
 of their volume, the augmentation or diminution of their 
 temperature and the production of muddiness in the water. 
 Artesian wells are similarly affected. Sometimes the occasion 
 is signalized by the escape of mud, water, gas, or flames. Oc- 
 casionally, as in the Andalusian earthquakes of 1884, the 
 ground is rent open for considerable distances. During the 
 frightful disturbances of Calabria in 1783, the phenomena 
 of ground-ruptures ranked among the grandest and most fear- 
 ful effects of the catastrophe. Whole mountain sides, under- 
 mined by water, slid down in mass, and tumbled into the 
 plains below, covering all the cultivated ground. Cliffs fell 
 down in a body, and rocks opened, swallowing the houses 
 which stood upon them. At the western base of the granitic 
 chain of the peninsula, the ground affected by the shock was 
 
THE UNSTABLE LAND. 105 
 
 cleft open for a length of more than eighteen miles, and in 
 some places, the fissure was several yards in width. In 
 another place, a cleft occurred 131 feet deep, over a mile long 
 and 32 feet wide. Sometimes the disturbances of an earth- 
 quake leave the surface permanently elevated or permanently 
 depressed. In one remarkable instance in the country of 
 Cutch, the Great Runn sank down over an extent of some 
 thousands of square miles, so that, during a part of the year, 
 it remained inundated by the sea, and during another part 
 was a desert without water. 
 
 A few other facts connected with earthquakes must be 
 mentioned, and then we will endeavor to ascertain how they 
 are caused. Through the monumental patience and industry 
 of M. Perrey, we have been placed in possession of thousands 
 of statistics of earthquakes between 1842 and 1850. Through 
 the similar labors of Mr. Robert Mallet and his son John W. 
 Mallet, we have been placed in possession of the facts respect- 
 ing other earthquakes between 1606 B. C. and 1842. From 
 both sources we have a record of six or seven thousand sepa- 
 rate earthquakes. The laborious discussion of this immense 
 catalogue shows very important results respecting the distri- 
 bution of earthquake occurences through the year. Earth- 
 quakes are found to occur most frequently at new and full 
 moon ; also, more frequently at perigee than at apogee ; also, 
 more frequently when the moon is on the meridian than when 
 in the horizon ; also, more frequently in winter than in sum- 
 mer; and finally, more frequently at night than during the 
 day. The results of this interesting analysis we will presently 
 apply to earthquake theory. 
 
 It requires but little acquaintance with the phenomena 
 usually ascribed to earthquakes, to discern that they do not all 
 belong to one class. Most widely destructive earthquakes are 
 characterized by vibrations of the earth, and these alone are 
 admitted by Mallet as true earthquakes. These may be de- 
 nominated earthquakes of vibration. Other movements of the 
 earth are translatory. The surface is bodily uplifted or 
 depressed, or both alternately. This may be denominated an 
 
106 WALKS AND TALKS. 
 
 earthquake of translation. This species may become destructive, 
 especially in a secondary way, when occurring either on land 
 or under the sea, in such relation to sea-level as to cause a 
 rush of the sea upon the land. With this discrimination in 
 view, let us consider what causes may be assigned. 
 
 The earthquake of vibration is evidently caused by a sud- 
 den blow or jar ; the earthquake of translation, by a lift, either 
 permanent or transient. 
 
 From time immemorial earthquakes have been connected 
 in the minds of men with volcanic action ; but careful study 
 shows no uniform correlation between them. Volcanic action, 
 moreover, is too local and too feeble. Some, in modern times, 
 attribute earthquakes to the movements of the molten interior 
 of the earth, acting against the walls of its prison; or as re- 
 sulting from some other mechanical action within the crust. 
 This opinion is supported by most reputable names Hum- 
 boldt, Scrope, Sir William Thomson. Movements of trans- 
 lation are undoubtedly produced by volcanic forces. Portions 
 of mountains are lifted or even blown away; fissures are 
 caused and many distinct movements result, which are com- 
 monly embraced under earthquakes. Undoubtedly, it some- 
 times happens, also, as an incident of volcanic action, that 
 sudden blows, or violent explosions occur which impart vibra- 
 tory tremors on a narrow scale, in character like those which 
 sometimes spread over kingdoms and work vast destruction. 
 But it can not be admitted that earthquakes as best known 
 earthquakes of vibration are ascribable to any volcanic 
 agency. 
 
 It may be mentioned, also, that the fall of large rocks, 
 mountain-slides, great explosions, whether natural or artificial, 
 sometimes occasion genuine earthquake tremors. The jar of 
 a train of freight cars, or of a loaded. wagon on the city pave- 
 ment, generates real earthquake tremors; but in all these 
 cases, on a scale too insignificant to be dignified with the name. 
 
 What is it, then, which stands as the physical cause of 
 those blows or shocks which, originating at certain foci in the 
 earth, spread radially in earth vibrations which sometimes 
 
THE UNSTABLE LAND. 107 
 
 level cities? I venture to affirm, with Mallet, Oldham, 
 Schmidt, Hottinger, and Bocardo, that it is a sequence of accu- 
 mulated strains resulting from lateral pressure in the earth's 
 crust. There are two assignable causes of enormous lateral 
 pressure. First, as maintained by Constant Prevost, the solid 
 crust formed around a cooling molten globe, becoming too large 
 for the shrunken nucleus, strives to adapt itself to the dimin- 
 ished interior (molten or solid). It is, therefore, laterally 
 pressed. Eelief is obtained, in part, by the development of 
 wrinkles, as in the skin of a shriveled apple, and in part, by 
 a process of crushing together. The strains are temporarily 
 resisted, but soon the crust must yield. As the crust is not 
 homogeneous, there must be stronger and weaker portions. 
 The motion which results, in the crisis of yielding, is accumu- 
 lated in isolated spots. If the pressure is a direct and simple 
 crushing pressure, then heat results from the crushing, lava is 
 formed and the pressure existing squeezes it, or the formation 
 of steam lifts it, to the surface. If the pressure has not a 
 simple, crushing tendency, there may arise a fracture. Then, 
 in an instant, the strain is removed; the rocks recoil, and the 
 vibratory motion is generated. 
 
 These lateral strains are augmented and localized by the 
 attractions of the sun and moon, which cause real tidal eleva- 
 tions and subsidences, and thus bring the crust to a snapping 
 tension, where the slow processes of terrestrial contraction had 
 not yet reached it. These tidal strains are greatest when the 
 moon and sun are nearest the earth, and also when they act 
 together, as at new and full moon. 
 
 To add another word. While a tornado or cyclone is at 
 its acme of violence, the barometer is low; the pressure of 
 the atmosphere on the earth is diminished at the spot, and 
 elsewhere correspondingly increased ; the terrestrial crust must 
 therefore, tend to develop movements of the nature of tides; 
 and the predisposition to earthquake actions must be aug- 
 mented. Observation indicates the frequent actual coincidence 
 of earthquakes and cyclones. Similarly, a connection has 
 been observed between the pressure of the atmosphere and 
 
108 WALKS AND TALKS. 
 
 the flow of springs, and the discharge of oil or gas from 
 natural or artificial openings. Many springs and wells show 
 a daily periodicity in the volume of the flow, corresponding 
 with the diurnal variations in the pressure and temperature of 
 the atmosphere. Such facts increase the presumption that 
 lunar and solar tidal actions may affect the flow of molten 
 matter, and also the distribution of stresses and movements in 
 the earth's crust. 
 
 XI2C THE KRAMEWORKOKTHK MOUNTAINS. 
 
 MOUNTAIN STRUCTURES. 
 
 LET us imagine ourselves standing on the bald summit 
 of Mount Marcy. This is the highest peak of the Adirondacks. 
 It rises 5,400 feet above sea-level. Beneath us, on every side, 
 spreads a wilderness of mountain swells and intervening 
 wooded valleys. In the dim and smoky horizon, in some direc- 
 tions, we glimpse the indications of white villages and smoking 
 chimneys, and crawling locomotives, and navigated waters ; 
 but the aspect, on the whole, is one not suggested by the knowl- 
 edge that we stand in the Empire State with its five millions 
 of citizens. Here nature still rules in one of her wildest moods. 
 
 Notice the forms of these summits. How symmetrically 
 the contour sweeps from the lower and flatter slopes upward. 
 How gracefully these mountain swellings dissolve in the green 
 ground of the landscape beneath. Look at our feet; the 
 naked rock lies cracked and weathered by the frosts of un- 
 numbered Winters. The chips of the mountain strew the 
 cone for eight hundred feet below. There the mountain firs, 
 shrinking from the weather, begin to appear, but only as 
 prostrate, crawling, and stunted shrubs. These rocks are 
 Eozoic. How hard and crystalline and stubborn they look. 
 These black crystals are pyroxene] the dark, dusky ones are 
 a species of feldspar called labrad&rite. The mixture forms a 
 rock known as Norite. Polished surfaces present a highly 
 pleasing appearance. This rock forms all the central mass of 
 
THE FRAMEWORK OF THE MOUNTAINS. 109 
 
 the mountain under us. It is but indistinctly stratified ; but 
 we believe it was originally formed from ocean sediments. It 
 has a granitic aspect, and, in a general way, we speak of it 
 as having a granitic character. 
 
 It is not an easy matter to travel down the slope of this 
 summit, over the loose crags, down into the border of the 
 forest, through the forest to the foot of the mountain, into 
 the lumber camps, down to the clearings, amongst the log 
 cabins, on to the village, over the highway and the railroad, 
 and ascertain at every step, what kind of rock underlies. 
 There is too much rock-rubbish, too much soil, too dense an 
 undergrowth. But the geologist must ascertain by some means. 
 How arduous are the labors by which the investigator works 
 out the geology of a wild region. To read a report of results 
 reached, as left by Professor Ebenezer Emmons, is easy ; but 
 when we visit the wilderness and test its difficulties, and re- 
 flect that Emmons wrote a description of the structure of the 
 Adirondacks forty-five years ago, we become deeply impressed 
 by the energy and skill brought into exercise by the older 
 geologists. To a great extent, the difficult work has been 
 accomplished. 
 
 When, therefore, we descend from the summit of Mt. 
 Marcy, we come, part way down the slope, to massive gneisses. 
 They rise up into view from the lower levels. They present 
 their crumbling and hoary outcrops looking up toward the 
 summit of the mountain, as if ambitious to attain the apex, 
 but wearied and wasted, and arrested by the way. Here they 
 lie, resting on their granitic bed. All around the mountain, 
 the upward looking outcrops of gneisses occur. The head of 
 Mt. Marcy rises above the heavy blanketing of gneiss. 
 
 Down the mountain to the lower levels we continue our 
 exploration. Here the exposed outcroppings of other gneisses 
 are seen enwrapping the lower and older ones ; here schists 
 hornblendic and micaceous come into view in succession, 
 overlying the beds whose outcrops are higher up, and all dip- 
 ping steeply down ; here is a thick bed of crystalline marble, 
 green-stained with intermingled serpentine. Here are beds of 
 
110 WALKS AND TALKS. 
 
 iron-ore, and other schists and conglomerates, all dipping still 
 down the slope, and each new one in succession reposing on 
 the top of the -last. 
 
 Should we descend the slopes of the Adiron clacks in a 
 hundred directions, such would be the succession of the for- 
 mations such, at least, the plan of the mountain structure, 
 though the particular kinds of gneiss or of schist would vary 
 on different sides. Let us think about the nature of this 
 arrangement. It looks as if the gneiss and schists had once 
 lain horizontal, and the head of Mt. Marcy, and the heads of 
 the other mountain giants, had been thrust up through 
 bursting the sheets of gneiss and schist parting them to the 
 east and west, the north and south continuing to push up a 
 mile toward the sky, and leaving the parted borders of the 
 bedded rocks far down the slopes separated by the diameter 
 of the mountain mass. It looks so and that is the ground 
 for the inference that it was so. We have been contempla- 
 ting forces possessed of the ability to perform such a piece of 
 work. Kra-kat'-o-a was split from bottom to top in 1882. If 
 volcanic forces should prove inadequate, we can invoke other 
 forces. We will invoke them. But let us see further what 
 there is to summon them to accomplish. 
 
 We are strolling upon the flanks of the Adirondacks. We 
 are now on the borders of civilization. Mt. Marcy looks 
 down on us from the cold blue sky against which his profile 
 is printed. We tread now on another soil. Here are massive 
 cliffs of sandstone. If we wander around by the east, we may 
 trace the Au Sable toward its source. We find it roaring 
 through a cleft in a gray sandstone with perpendicular walls 
 one hundred feet high, and along a chasm which splits the 
 formation for a distance of two miles. This is the chasm of 
 the Au Sable. But see, this sandstone is not a metamorphic 
 rock. It lies above all the gneisses and schists. It is not so 
 steeply inclined. Evidently it is not within the Eozoic Great 
 System ; it is Palaeozoic. Follow it as it stretches under the 
 country to the eastward. It extends to Lake Champlain. It 
 reappears on the Vermont side, and continues to the Green 
 
THE FRAMEWORK OF THE MOUNTAINS. Ill 
 
 Mountains. If we carry our observations to the north flanks 
 of the Adirondacks, there too, we find this sandstone. The 
 charming village of Potsdam is built on this sandstone a 
 classical spot which has given its name to a formation that 
 reappears in all countries. Here certainly, if nowhere else in 
 northern New York, the geologist receives a cordial greeting 
 and geology finds warm appreciators. This sandstone spreads 
 out horizontally to the St. Lawrence River. If we examine 
 the Adirondack slope on the west, the Potsdam sandstone is 
 found in its place, and even limestones come in succession, in 
 higher geological positions above the sandstone. On the 
 south we still find the sandstone. 
 
 The appearance now is, that after the granite center had 
 burst through the gneisses, and all these rocks were standing 
 at a level somewhat lower than at present, the ocean still 
 covered the flanks now overlaid by the Potsdam sandstone, 
 and on the bottom of that ocean the sands were spread which 
 were destined to become consolidated as sandstone; then, after 
 this, there was a farther uplift of the Adirondack mass, bring- 
 ing the Potsdam sands above sea-level, around their border, 
 and giving them also a tilt, while the gneisses received an in- 
 creased tilt. So the granitic center of the Adirondacks was at 
 first a small island ; then, by further upheavals, the island was 
 enlarged progressively on all its borders. 
 
 Now let us proceed across the St. Lawrence valley. Here 
 we find horizontal Potsdam sandstone stretching up and down 
 the valley; and above this, a thick series of limestones. Con- 
 tinuing toward the Lauren tide Hills, we see the horizontal 
 strata turning up gently. We ascend a gradual slope, and 
 by and by, the limestones end. A steeper ascent is still under- 
 laid by the Potsdam sandstone. Here now, is the end of the 
 sandstone and we step on schists and gneisses and crystalline 
 limestones, each rising from under the preceding, until we 
 reach granitic rocks, which continue to the summit of the 
 ridge. Then passing still northward, we meet various for- 
 mations like those seen in ascending the ridge, but in the in- 
 verse order. In fact, the nature of the rocks, their altitudes 
 
112 WALKS AND TALKS. 
 
 and their order of arrangement are exactly like what we found 
 in descending the Adirondack^. 
 
 The Laurentian, therefore, has the same constitution as 
 the Adirondacks. It is an elongated elevation, however, in- 
 stead of a cluster of peaks. It presents an anticlinal structure. 
 The oldest or bottom rocks are in the center, and rise to the 
 highest altitude. The rocks geologically higher in position 
 attain to successively lower and lower altitudes; they dip down 
 on each side of the granitic axis, like a series of planks lean- 
 ing against a stone wall. 
 
 This is the general plan of a mountain of upheaval. We 
 find the same in the Blue Kidge, in the ranges of the Rocky 
 Mountains and many others of the great ranges of the country. 
 Mountains, therefore, exist as long folds of the earth's crust; 
 and very generally, where one fold exists, two or three others 
 exist parallel with this, as in the Appalachians. 
 
 It will be borne in mind always, that every orographic or 
 mountain feature has undergone a great amount of alteration. 
 The summits of the mountains have been much lowered. The 
 strata enwrapping their flanks have been cut back ; they stretch 
 to less distances than formerly toward the summit. In many 
 cases, indeed, we have room to conjecture that they extended 
 originally over the summit, and have been worn away in the 
 course of ages, uncovering the granitic nucleus only in later 
 geological time. 
 
 In some cases, the erosion of parallel and contiguous mount- 
 ain crests has proceeded so far that the summits are lower than 
 the valleys between them. The valleys then become the mount- 
 ains, and in place of the original mountains are valleys of 
 erosion. So we sometimes find a synclinal structure in mount- 
 ains, and an anticlinal structure under valleys. Sometimes we 
 find a river cutting through a mountain from side to side and 
 from top to bottom. The Green river in Wyoming, affords a 
 striking example. It cuts through the 15,000 feet of the altitude 
 of the Unita Mountains. It seems quite evident that the river 
 was here before the mountain. The mountain rose gradually 
 under the river, and as it rose, the river sawed its gap to the 
 
THE MOUNTAIN FKAMEWORK. 113 
 
 bottom, and the walls of the gap were left to rise precipitously 
 on each side. Other mountains have been rent by fissures. 
 These generally run lengthwise of the range most frequently 
 along the center. When they exist, the strata on one side are 
 generally found depressed below the level of the corresponding 
 strata on the other side. Such a case is a fault. In the Appa- 
 lachians are faults of five thousand to twenty thousand feet. 
 A greater one cuts through the Uintas. The Sierra Nevada, 
 for three hundred miles, has been split lengthwise along the 
 middle, and the eastern half, for a large part of the distance, 
 has gone down three thousand to ten thousand feet. So the 
 west half the Wahsatch went down forty thousand feet for a 
 length of at least one hundred miles. 
 
 Of mountains of relief, like the Catskills and the Cumber- 
 land Table Land, something has already been said in Talk IX, 
 and nothing more is necessary here. Mountains composed of 
 volcanic accumulations are mentioned in Talks XV and XVI. 
 
 . How THE MOUNTAIN KRAMEWORK is 
 
 MOUNTAIN FORMATION. 
 
 BY what machinery were these mountain masses upraised? 
 By what motive force was it actuated? When we look up 
 toward the sky and see the form of Mont Blanc profiled 
 against the clear blue far away far up where the white 
 clouds cap the mountain's hoary head, we realize partially 
 that an enormous power has been exerted ; we reflect that the 
 upraising of a mountain was as truly a mechanical work as 
 the erection of the obelisk in Central Park. Let us try to 
 reproduce to imagination the process by which Nature builds 
 the great mountains the great mountains of upheaval. 
 
 Generations past, which had witnessed the tremendous 
 power of Vesuvius and ^Etna, thought the volcano adequate 
 for the production both of earthquakes and mountains. It 
 was steam and gases trying to find vent, they said, which 
 
 10 
 
114 WALKS AND TALKS. 
 
 shook the ground and bulged the terrestrial crust into mount- 
 ain saliences. They had seen mountain caps blown off, and 
 mountains cracked open"; they had even seen Sabriiia and 
 Graham's Island and many ^Egsean islands lifted from the 
 bottom of the sea, and sustained at an elevation of some hun- 
 dreds of feet. Were not these efforts at mountain-making and 
 unmaking? Had it not been ascertained, too, in more recent 
 times, that Vesuvius and jiEtna, with all their loftiness and 
 massiveness are mere piles of stuff brought up by volcanoes, 
 and builtj by volcanic action into mountain forms ? Is not 
 Mt. Hood a pile of lava? And who can affirm that Ranier, 
 Lassen, St. Elias, Popocatapetl, Cotopaxi, are not similarly 
 masses of piled up lavas? 
 
 Yes, the reasoning is good for a certain class of mountains. 
 But the Adirondacks are not a pile of lava ; nor the Lauren- 
 tides; nor the Appalachian ranges; nor the White Mount- 
 ains; nor the Rockies. Here has been lifting to which 
 all volcanic work bears a very feeble comparison. If 
 .^Etna and Hood are piles of volcanic debris, consider how 
 small a part was lifted at once. The ascent of the mount- 
 ain materials has been like that of wheat in the grain 
 elevator little at a time, but much in the aggregate. 
 Look at the Adirondacks, on the other hand here is a vast 
 framework; all the parts were formed and adjusted together 
 before the uplift; and when the time arrived, the total mass 
 was raised in one stupendous mechanical effort. We must 
 seek a greater power than the volcano. 
 
 It is not a trivial problem. It has puzzled the most ex- 
 pert of brains. But I think you have made the acquaintance 
 of forces and modes of action which furnish us a real clew to 
 the mechanism of mountain making. Your attention has been 
 directed to many indications of the presence and action of 
 heat in the earth. You have even reached the inference that 
 the earth is a cooling globe. [But see further in Talks 
 XXXVII and XXXVIII.] Now, you have often witnessed 
 the power of heat. When it enters a solid or liquid, expan- 
 sion takes place, and the power of expansion surpasses human 
 
THE MOUNTAIN FRAMEWORK. 115 
 
 control. When it leaves a body contraction ensues, and the 
 strength of this tendency can not be resisted by any means in 
 our power. Loss of heat is always attended by contraction 
 except when the temperature is a few degrees above that at 
 which the body passes from the liquid to the crystalline solid 
 state for there is a certain critical point at which reduction 
 of temperature begins to be accompanied by expansion, until 
 the solid condition is attained; after which further reduction 
 is attended again by contraction. 
 
 Now, ever since Leibnitz, two hundred years ago, enun- 
 ciated his theory of a once molten earth, geognostic students 
 have been considering what must be the natural course of 
 events in the cooling of such a globe. Constant Prevost ad- 
 vanced a suggestion sound in theory and fruitful in conse- 
 quences. That molten globe, he said, must have become 
 incrusted. By degrees the crust would thicken, and the trans- 
 mission of heat from the interior would be retarded. By and 
 by, the radiation of heat from the exterior would become 
 diminished to such an extent as to just equal the heat received 
 at the surface by transmission through the crust. That is, a 
 constant temperature would exist at the surface of the earth 
 a constant temperature at the mid-zone in the crust. But the 
 interior would still continue to lose heat through the crust, 
 though the crust retained a uniform temperature. It the interior 
 did not supply heat to the crust, the latter would grow colder. 
 
 So the interior, in consequence of loss of heat would con- 
 tract ; but the crust, losing no more than it receives, would 
 not contract. That is, the crust would become too large for 
 the shrunken nucleus. What would result? Do you con- 
 ceive that the crust would rest raised above the nucleus, 
 leaving vacant, or even steam-filled spaces between the two ? 
 Renumber the enormous weight of the atmosphere fourteen 
 pounds on every square inch. Remember the enormous weight 
 of the crust, and the utter impossibility of its sustaining the 
 strain of bulging over a vacuum of one, ten or a hundred 
 miles. Assuredly, the crust must settle down as fast as the 
 molten nucleus grows smaller. 
 
116 WALKS AND TALKS. 
 
 But now, in settling down, its circumference must con- 
 stantly become less. How can its circumference be made less ? 
 Only by squeezing together from all directions. There must 
 be a lateral pressure experienced at every point. It arises 
 from the weight of the crust, and is proportional to the weight 
 of the crust. If the crust is thus subjected everywhere to an 
 enormous lateral pressure, then, either the parts of the crust must 
 be mashed together, producing a thickening in proportion to dimi- 
 nution of circumference ; or else, if the crust is too solid to be 
 crushed, it will wrinkle just as the skin of an apple is wrinkled, 
 when the pulp within shrinks through the evaporation of juice. 
 
 Now, suppose that stage of things has been reached. Some 
 wrinkles have made their appearance on the surface of the 
 earth. They are the beginnings of mountains. If ocean 
 waters rest now on the earth's surface, they may, indeed, totally 
 cover these wrinkles but they are the germs of mountains, 
 nevertheless. As long as the earth's interior continues to lose 
 heat and contract, so long wrinkling tendencies will exist. 
 But, after a set of wrinkles has been first developed, the 
 wrinkling tendency afterward finds relief in the same 
 wrinkles in the enlargement of the first wrinkles. The power 
 to enlarge and further elevate the old wrinkles will be attained 
 before the power to initiate wrinkles in new places. In this 
 way, the germinal mountains would grow. In this way, the 
 first uplifted masses would afterward be uplifted higher, as 
 new relief had to be sought. Did we not observe the succes- 
 sive stages of uplift in our study of the Adirondacks ? 
 
 There is no volcanic uplifting here. It is true, however, 
 we may get volcanic phenomena. The crust presses with 
 enormous weight on the molten ocean. Compare it with a 
 field of ice a mile square and three feet thick, floating on a 
 lake. If you make a hole through the ice, the water rises in 
 the hole, nearly to the surface of the ice. If the hole is sud- 
 denly made, the water may rise with such velocity that its 
 momentum will carry it quite to the surface, or over the sur- 
 face. This is like an outflow of volcanic matter through a 
 fissured crust. Suppose a great number of piles of ice be 
 
THE MOUNTAIN FRAMEWORK. 117 
 
 heaped up on this ice field in various parts. Then, if a hole 
 be pierced through, the water will rise with increased likeli- 
 hood to overflow. Now these piles of ice exert an effect similar 
 to that of upraised wrinkles in the crust. So it appears that 
 volcanoes may be an incident of the earth's contraction, as 
 before stated, and that mountain-making may be another in- 
 cident of the same. But there is more to be said. In many 
 places must occur some crushing together. In the mountain 
 folds where the internal constitution and firmness have been 
 strained by flexures, there must be weakness ; and there must 
 occur some of that mashing together which develops heat, inde- 
 pendently of any supply from the molten interior. It is quite 
 intelligible, therefore, that a mountain wrinkle or fold is a 
 zone where heat must be generated, even if lava is not pro- 
 duced, and does not escape from within. Along a mountain 
 fold, in other words, is a zone where the rocks must be sub- 
 jected to that baking or semifusion in connection with water, 
 which produces the changes called metamorphism. 
 
 It would not be proper to leave the subject in this state, 
 though you have already the gist of the theory of mountain 
 making. If you observe shrewdly, you will discover two 
 features in our mountains on which no light has been thrown. 
 You may experience some difficulty in understanding the ex- 
 planations. But let us try. You know well that all our great 
 mountains exist as long ranges mostly as groups of ranges, 
 and that the prevailing direction of mountain trends is approx- 
 imately north and south. Now, when we consider the wrinkles 
 on the skin of a withered apple, we find them short, and hav- 
 ing also, no uniformity of trend. The analogy is imperfect. 
 There must have been some other cause than uniform shrinkage 
 to develop the actual mountain folds. 
 
 Let us glance black over the early history of the earth. 
 They tell us it once revolved much more rapidly on its axia 
 than at present. It is not difficult to understand why its rota* 
 tion has been retarded, but w r e will pass that by. If the rotation 
 has slackened, then the equatorial protuberance has diminished. 
 That is, the equatorial circumference has been shortened more 
 
118 WALKS AND TALKS. 
 
 than the polar ; and consequently there has been more lateral 
 pressure around the equatorial region. That pressure too was 
 exerted east and west, and that was just the direction which 
 would give to the wrinkles a north and south trend, and a con- 
 siderable elongation. Besides this, there was a powerful tidal 
 attraction exerted by the moon (see also Talk XXXVIII). 
 That body was then much nearer the earth than now, and 
 exerted important influences on the earth. In our times, it 
 raises the ocean and the whole hemisphere in a tidal swell ; 
 then, though no ocean existed, the tidal swell was raised with 
 the forming film over its surface. But the rise of the swell 
 was not instantaneous ; it reached its height after the moon 
 had passed the meridian to the west, and the moon acting on 
 it from that position, pulled the apex slightly westward, and 
 thus established changed conditions in the crust which neces- 
 sarily had a north and south trend, and contributed something 
 to give the wrinkles which were then forming, the north and 
 south axes which we see in mountain ranges. 
 
 Another peculiarity of mountains is the greater thickness 
 of the formations and the greater proportion of fragmental 
 strata. This has led some to conceive that the materials of 
 mountains were accumulated in the bottom of the sea, in sit- 
 uations to which ocean currents brought unusual quantities of 
 coarse deposits from neighboring continental shores. It is sup- 
 posed that these sediments depressed the bottom and thus pre- 
 served such depths as would continue to invite the currents to 
 a continuance of their work, until the mountain mass was 
 completed. The sinking of the great synclinal must have 
 subjected the materials to the metamorphic influence of inter- 
 nal heat, even without any crushing together. Probably, in 
 this state of things, metamorphism resulted from both causes. 
 Then in due tine, the synclinal was upraised, with additional 
 crushing, and the mountain was completed. 
 
 These are but glimpses of the theory of mountain-making ; 
 but I hope they will stimulate you to further study. Let me 
 recommend the re-reading of this Talk, after Talk XXXVIII. 
 
DOWN IN A MINE. 119 
 
 XXI. DOWN IN 
 
 MODES OF OCCURRENCE OF THE METALS. 
 
 WHO has not heard of the Comstock Lode ? Who has 
 not read something about the hundreds of millions of gold 
 and silver extracted from its deep depositories ? What names 
 in the annals of mining enterprise are more familiar than 
 those of Gould and Curry, William M. Stewart, Adolf Sutro, 
 James G. Fair, J. W. Mackey, John P. Jones, William 
 Sharon ? What is the Comstock Lode ? It is a body of gold- 
 and-silver-bearing mineral matter lying in the Virginia range, 
 a spur of the Sierra Nevada, about 25 or 30 miles east of the 
 Sierra crest. The range trends a little east of north, and the 
 lode appears to be the filling of an imperfect fissure four or 
 five miles long the principal part of which is about 10,000 
 feet. The fissure extends into the mountain with an eastward 
 dip varying from 33 to 45. At the north end it divides 
 into three or more diverging and somewhat irregular branches, 
 and at the south end it terminates in two branches. The 
 fissure has, at its broadest part, along the middle, a width 
 of about 600 feet, which becomes 1,400 feet when measured 
 along the sloping surface ; and it narrows toward each end. 
 The lode also narrows downward, and at about 1,800 feet ver- 
 tically, has a thickness of about 120 feet. The part above 
 this seems to be formed from two fissures and the wedge- 
 shaped mass of "country rock" included between them. 
 This wedge of country rock was cut off from the east side, 
 where the rock is diabase that is, composed of grains of 
 augite and a plagioclase feldspar. On the west side, the 
 country rock is diorite that is composed of hornblende and a 
 plagioclase feldspar. In miners' language a fragment of 
 country rock included in a lode is a " horse." The fissure 
 along each side of this enormous " horse" is filled chiefly with 
 quartz. The east wall in this case, is the " hanging wall," 
 and the west, is the "foot-wall." The hanging wall is much 
 decomposed, and the decomposition extends through the dia- 
 base for five thousand feet. 
 
120 WALKS AND TALKS. 
 
 The contents of the lode are somewhat miscellaneously dis- 
 posed. Besides the great prismatic horse just mentioned, are 
 many smaller fragments of country rock, together with clay, 
 quartz and silver-bearing minerals. Most of the ore contains 
 both silver and gold, but the proportions of the two metals vary 
 in different parts of the lode. From the whole lode the yield of 
 gold has been 43 per cent and of silver 57 per cent. The 
 richest quartz lies nearest the hanging wall. A mass of ore 
 rich enough to pay for working is styled a " bonanza." An ore 
 must afford fifteen or twenty dollars a ton to pay. The cele- 
 brated "great bonanza" averaged $80 to the ton. It was 
 composed of crushed quartz, including fragments of country 
 rock, and carried a few hard, narrow, vein-like seams of very 
 rich black ores; while nearly the whole mass of the crushed 
 or "sugar quartz" was impregnated, to a moderate extent, 
 with native gold and stephanite, which is an arsenical sulphide 
 of silver known sometimes as brittle silver glance. Even the 
 country rock was also charged with these ores. 
 
 It would not be proper to enter further into particulars of 
 this kind. But glance a moment at the mechanical operations. 
 Perhaps you think the miners attacked the wonderful Lode at 
 its outcrops, and followed it down on a slope into the earth. 
 Not at all. As soon as this method of exploration had re- 
 vealed the position and promise of the lode, great capitalists 
 laid out the work according to methods sanctioned by centu- 
 ries of experience in other countries. Going some hundreds 
 of feet to the east of the lode, a vertical shaft would be sunk 
 until the lode was struck. At frequent intervals, horizontal 
 passages were excavated westward to the lode, and through 
 the lode to the foot wall. From these, other passages or gal- 
 leries were excavated along the lode. From these numerous 
 galleries, the various ore-bodies were discovered and worked 
 out, within the limits of the claim. There is a large number 
 of claims or properties along the lode, and there are twenty- 
 four shafts sunken on the east. In course of time, the va- 
 rious mining operations have been brought into some degree 
 of concert and system. Without this, the difficulties of the 
 
DOWN IN A MINE. 12] 
 
 tieep exploitation of the lode would have been insuperable 
 The country has thus become honey-combed to a depth of 3,000 
 feet. The total length of the galleries driven exceeds 15C ? 
 miles. 
 
 Heat and water have presented obstacles most formidable. 
 The high temperature of the rock and of the water escap- 
 ing from it are very extraordinary. In the Clifford mine 
 in Wales, water heated to 125 has been encountered. But 
 on the 3,000 foot level of the Comstock, floods of water have 
 entered the mines at 170. Water at this temperature will 
 cook food, and will destroy the human epidermis. A partial 
 immersion in it is therefore fatal. The atmosphere, as a con- 
 sequence, is not only intolerably hot, but is saturated with 
 vapor. From prolonged exposure to these unnatural condi- 
 tions, many miners have lost their lives. In the Savage mine, 
 in 1879, the miners struck a hot spring having a temperature 
 of 157, and the incline was filled with scalding vapor ; picks 
 could only be handled with gloves, and rags soaked in ice- 
 water were wrapped about the iron drills. Occasionally, per- 
 spiration would cease, the miner would begin to talk in a 
 rambling fashion, and his death would soon ensue, unless re- 
 moved by his comrades to a place of relief. The conditions 
 of mining are greatly ameliorated by most efficient ventila- 
 tion through the 150 miles of galleries and the shafts. Still, 
 the air leaves the mines nearly saturated with aqueous vapor, 
 and at an average temperature of 92. 
 
 The increase of downward temperature here greatly ex- 
 ceeds the general average. In one shaft at 100 feet, the tem- 
 perature was 50; at 200 feet, 55; at 500 feet, 68; at 800 
 feet, 76; at 845 feet, 80; at 1,100 feet, 92. In another 
 shaft, at 1,500 feet the temperature was 105; at 1,600 feet, 
 107; at 1,700 feet, 108; at 1,800 feet, 111; at 1,900 feet, 
 112; at 2,000 feet, 113; at 2,230 feet, 121. Mr. Church, 
 who investigated this subject very carefully, estimated the 
 mean temperature on the 2,000 foot level, at 130. The 
 water at 170, with which the Gold Hill mines were flooded 
 i the winter of 1880-1, entered on the 3,000 foot level, and 
 
 11 
 
122 WALKS AND TALKS. 
 
 was struck at 3,080 feet. All the data together indicate an 
 increase of temperature of one degree for 28 feet of depth. 
 This abnormal increase appears confined to the vicinity of the 
 lode. The great Sutro Tunnel, which approaches the east 
 wall at a depth of 1,900 feet, indicates a great increase of 
 temperature in approaching the wall. At the distance of 128 
 feet, the temperature is 110; at 1,048 feet, 108; at 2,052 
 feet, 96; at 3,651 feet, 89; at 5,008 feet, 87; at 7,175 
 feet, 85; at 9,512 feet, 83; at 10,849 feet 79. This great 
 increase of temperature can not be attributed to the increase 
 in depth of the tunnel below the earth's surface. The ex- 
 traordinary temperature, therefore, is a phenomenon of the lode. 
 It appears to rise from some greater depth, and the indications 
 point to ascending water as the probable agent in bringing up 
 the heat from a deeper region. It acts, therefore, like an 
 enormous hot spring. Thirty miles away is the Sierra Nevada 
 range, and from the altitude of perpetual snow, the eastward 
 dipping strata descend into the earth for a great depth. The 
 water which accompanies them reaching the deep portion of 
 the Comstock Lode, their course is in part arrested by the 
 impervious clays. When reached therefore by the mining 
 operations, the relief of pressure causes them to rise from 
 depths much below the bottom of the works. 
 
 The waters just mentioned constitute the second powerful 
 obstacle to mining on the lode. In the deeper works, the 
 volume has assumed portentous proportions. The water was 
 originally pumped to the surface through the vertical shafts. 
 Steam-pumps of ever increasing capacity, however, proved 
 successively inadequate to the demand. Hence, the daring 
 enterprise of Adolf Sutro conceived the tunnel which bears 
 his name, and which, through thirteen years of opposition, he 
 fought to successful completion in 1878, at a cost of two mil- 
 lion dollars. The outlet of the tunnel is 20,000 feet from the 
 east wall of the lode. From the entrance, a lateral branch is 
 extended north along the lode 4,403 feet (to October, 1880), 
 and another lateral, southward, 4,114 feet. The tunnel is 
 seven feet in height, and eight feet in width in the clear, with 
 
DOWN IN A MINE. 123 
 
 a grade of one inch in 100 feet. In the bottom is a drainage 
 channel five feet wide and three and one-half feet deep. After 
 the mining companies began pumping water into the tunnel, 
 over three and a half million gallons were discharged every 
 twenty-four hours. During 1880, the aggregate was over a 
 billion and a quarter gallons, and it was estimated that double 
 this quantity would be discharged when connection should be 
 made with all the mines. The temperature of the mixed 
 water entering the drain is 137, and its temperature at the 
 mouth is 118. Little use is made at present of this stream 
 of water, amazing equally for volume and for temperature. 
 It is apparent, however, that this vast stream of hot water 
 possesses capabilities of usefulness which American enterprise 
 will not permit to run to waste indefinitely. 
 
 During twenty years, up to 1881, the bullion yield of the 
 Comstock Lode had been $306,000,000. Since 1874, business 
 on the lode has been much depressed. 
 
 Investigations have been made for the purpose of ascer- 
 taining the source of the precious metals in the lode. Mr. 
 George F. Becker has shown the presence of gold and silver 
 in the unaltered diabase rock on the east of the lode, and 
 demonstrated it practically absent from that part contiguous 
 to the lode which has undergone decomposition. It results 
 from his studies, that after the region had been shattered by 
 earthquake disturbances, floods of heated waters rose through 
 the rocks, carrying carbonic and sulphydric acids, and satur- 
 ating the east country, dissolving out silica and metallic salts, 
 and redepositing them again in the spaces comparatively open. 
 He finds by calculation that the total metal taken from the 
 lode is not in excess of that originally contained in the 
 diabase on the east, within the region now occupied by the 
 decomposed rock. 
 
 This explanation will apply to the accumulation of ore in 
 veins of a more typical character. The Comstock Lode can 
 scarcely be called a "true vein" in the accepted sense. A 
 vein proper is a fissure extending to a great depth in the earth, 
 and having generally a considerable longitudinal extent, with 
 
124 WALKS AND TALKS. 
 
 a width varying from a few inches to several feet, and with 
 its contents often arranged in layers upon each of the two 
 walls, in the same order from the wall. Each of these layers 
 is called a comb, and the whole is styled the gangue. The 
 metalliferous layer is the ore. Many of the most important 
 Old World mines are based on true veins. Many, also, in 
 America; but in many of the most celebrated mines", the 
 mode of occurrence of the ore is different. 
 
 In the Eureka mining district, in Central Nevada, we have 
 a regular succession of strata consisting of limestones, shales, 
 and quartzites, ranging from the Cambrian to the lower car- 
 boniferous, but mingled with porphyritic eruptions and all 
 shattered by a process of faulting. The silver-bearing lead 
 OBe is found imbedded in the lower Carboniferous Limestone, 
 within masses of hydrous iron oxide. The deposits are dis- 
 covered and worked out by a regular system of mining 
 through shafts and galleries; though, in the works of the 
 Richmond company, these formalities are discarded, and the 
 deposits are reached and worked out by the shortest cuts. It 
 can scarcely be said that the ore occurs here in veins. It lies 
 in masses having cavities above. Its origin is from below ; 
 but the stratified rocks have not served as its source. But 
 the quartz-porphyry of the region, by leaching with hot alka- 
 line waters, may have afforded the ore ; and this is thought 
 by Curtis to have been its probable source. 
 
 The silver-bearing galena of Leadville, in Colorado, ac- 
 cording to Emmons, has a similar mode of occurrence. The 
 deposit of the silver-bearing minerals took place in the lowest 
 member of the Carboniferous System. They were derived 
 from circulating waters, which obtained them in passing 
 through eruptive rocks. How introduced into the eruptive 
 rocks is a matter for speculation. 
 
 In the lead-producing region of Wisconsin, Iowa, and Illinois, 
 the galena and blende occur as a lining on the walls of cavities 
 or caverns in a magnesian limestone of upper Cambrian age. 
 In Missouri, similar cavities in the Lower Magnesian Limestone, 
 of lower Cambrian age, are found lined with galena and quartz. 
 
THE KING OF METALS. 125 
 
 KING OF" 
 
 IRON AND ITS GEOLOGY. 
 
 THE most useful of the metals is most abundant and most 
 universal. Iron is found in formations of every age, from 
 the Laurentian of the Eozoic to the Quaternary and even the 
 bogs which are forming in the age of man (Compare Talk V.) 
 As Iron has its innumerable uses wherever man makes his 
 dwelling on the earth, so Providence has distributed the metal 
 to all communities. It may be of interest to point out the 
 fact that we find iron most useful, not because most abundant 
 and most accessible, but because its properties give it preemi- 
 nent superiority. Gold and silver and platinum are wanting 
 in the hardness and rigidity which suit iron to many of its 
 most important adaptations. Neither of these metals could 
 be made into useful rails for the steam train to move on. 
 Neither would furnish a tool having the edge and temper of 
 fine cutlery. Iron has been brought so universally into sub- 
 servience to human wants, not because it is available, but be- 
 cause it is at once most suitable and most available. The wide 
 applications of iron are not the outcome of any fortuitous cir- 
 cumstances, but a result of coordinations planned in the con- 
 stitution of things. 
 
 Iron is almost universally disseminated, as a constituent, 
 through the rocks and minerals. It sometimes imparts a 
 black, and sometimes a red or yellowish color; and many 
 times its presence is unannounced by any color. This red soil 
 which, in some regions, prevails extensively, is colored by 
 iron. This red sandstone is colored by iron, this red shale, 
 this red brick like this red rust on the stove-pipe. This yel- 
 low precipitate in the bottom of the stream is the same with 
 water in combination. These are oxides. Now please, don't 
 be impatient at the mention of a chemical term. They hold 
 all the oxygen which the iron can take, and hence they are 
 called peroxides. But the yellow oxide holds water also, and 
 hence is known as a hydrated peroxide. Now follow this hy- 
 drated peroxide this yellow ocher down to the bog which the 
 
126 WALKS AND TALKS. 
 
 water saturates. Here is black muck a fine peaty material 
 but it is colored and charged with this ocherous deposit. 
 After some years, the peaty matter decays, and disappears, to 
 some extent. Then we see the iron compound aggregated 
 and compacted in irregular masses. It has now become 60^7 
 iron ore. It is a kind of limonite, so-called. It can now be 
 smelted in a furnace and the pure iron extracted. 
 
 If this swamp should be sunken below sea-level, and heavy 
 layers, of marine sediments spread over it, the bog ore would 
 be compressed into a compact stratum. Then if all these for- 
 mations should be converted to solid rock, our bed of bog ore 
 would be exactly such a bed of limonite as we actually find 
 in some situations deep in the rocks. It would be an old fossil 
 swamp. But suppose some thousands of feet of sediments should 
 be piled over it. Then the heat of the earth's interior would 
 come up and bake the ore-bed. Very likely the water would 
 be expelled from our limonite, and it would become simply a 
 peroxide it would assume a red color it would be hcematite, 
 which means blood-red ore. Now such beds of haematite form 
 many of our most valuable deposits of iron ore. Much of the 
 ore in the Lake Superior region is of this kind also in North- 
 ern New York and in other regions. But if this old hsema- 
 tite is left exposed to water for some years if the bed be- 
 comes soaked with water, it changes back to limonite; it 
 becomes yellow and somewhat soft. The miners sometimes 
 call it "soft hsematite." It is easily quarried and easily 
 smelted, and every body likes it though ton for ton of ore, 
 it contains less iron than hard or true haematite. 
 
 I do not assert that all limonite and hsematite have come 
 into existence in this way. But I am sure this theory is highly 
 plausible for some beds of iron ore. But now, I have noticed iron 
 ores in such situations that perhaps a different explanation is 
 more reasonable. I have seen great masses of iron ores inclosed 
 in the midst of great stratified formations. The ore-masses are 
 huge lenticular accumulations sometimes of great purity, 
 sometimes mixed with rocky matter, sometimes bounded ab- 
 ruptly, and sometimes blending gradually with the contiguous 
 
THE KING OF METALS. 127 
 
 strata. The ores occur in this way at Lake Superior. Such 
 masses of ore are almost always in crystalline inetaraorphic 
 rocks. They have been heated probably subjected to the 
 action of hot water. 
 
 There is another species of iron ore very commonly asso- 
 ciated with these. It is magnetite. This is composed partly 
 of peroxide of iron and partly of protoxide of iron that is, 
 iron with only one proportion of oxygen combined with it. 
 Magnetite is richer, therefore, than hematite ton for ton of 
 ore it contains more iron. While powdered haematite is red, 
 and powdered limonite, brownish yellow, powdered magnetite 
 is black. Magnetite attracts the magnetic needle. "Lode- 
 stone" is magnetite so-called, probably, because it leads by 
 its attraction. Now, magnetite is often found in great im- 
 bedded masses, like haematite, and is regarded one of the 
 most desirable of ores. Often haematite and magnetite are 
 mingled together in the same bed; and the indication is, that 
 one is capable of conversion into the other. 
 
 We often find, also, considerable formations in which 
 much iron ore exists in a disseminated state, imparting a 
 highly ferruginous character to the rock, but constituting 
 only a very "lean ore." It may be a haematitic quartzite or 
 a silicious haematite. We find all stages of transition from 
 pure ore masses to simple rock. The theory is often suggested 
 to me by the conditions under which these metamorphic ores ex- 
 ist, that they are simply accumulations of ores gathered together 
 from wide contiguous regions in the rock. It seems settled 
 that ores of lead, zinc, and silver are thus eliminated from the 
 country rock, as was explained in the last Talk. Hot, alka- 
 line waters are supposed to have had principal agency in the 
 work. But where the native metals occur, as gold, silver, or 
 copper, we must suppose that a dry fusing heat has been 
 present to reduce the ores previously formed, or drive together 
 metallic particles disseminated through the rock; or we must 
 suppose that an electro-chemical deposition has taken place 
 from a metalliferous solution, as in the electro-plating process. 
 In some way, at least, particles of a particular kind become 
 
128 WALKS AND TALKS. 
 
 aggregated in "veins," in "lodes," in "segregations;" and thus 
 the huge lenticular masses of haematite may have been formed. 
 
 Perhaps this theory is sustained by the relations of iron ores 
 to the stratification. Often all stratification is obscure or 
 wanting; often the stratification of the country rock can be 
 traced through the ore-body ; not unfrequently the ore-mass is 
 a vast stratified formation. Pilot Kuob, in Missouri, is a 
 great iron-schist a schistose formation in which the once dis- 
 seminated iron particles appear to have been driven by some 
 agency, into a particular part of the formation. In this case, 
 the richest part of the formation is at the pinnacle of the 
 knob, and the schist decreases in richness as we descend to 
 the base. 
 
 Now, there are two suggestions in reference to the way in 
 which iron ore particles have been accumulated first, fossili- 
 zation of ancient iron-bogs ; second, segregation. If the great 
 masses found in metamorphic strata seem rather to be the results 
 of segregation, some of the younger iron deposits appear to be 
 of the nature of fossilized swamps. Probably, too, some rich 
 stratified ores, like those back of Milwaukee, and those near 
 Rochester, New York, were precipitated in shallow seas the 
 iron brought in by springs. This is a third suggestion. 
 
 There is still another way in which iron combinations ap- 
 pear to accumulate. It is a modification of the segregation 
 process. You have seen, sometimes, in a yellowish or reddish 
 sandstone that is, a ferruginous sandstone some concentric 
 bands of a deeper color bands formed by an increased 
 amount of oxide of iron. Now observe that the lines of 
 stratification of the rock pass quite through these spheroidal 
 forms. It is manifest, therefore, that the spheroidal aggrega- 
 tions took place after the sediments were laid down after 
 the rock was formed. If so, then the iron material must have 
 moved through the consolidated rock. How did it move? 
 Could solid particles of iron-oxide travel from all directions 
 toward a common center, and all halt at a common distance 
 from that center? Evidently not, only pure water or clear 
 solutions could thus move. We may, therefore, conclude that 
 
THE KING OF METALS. 129 
 
 the iron was transported and accumulated in spheroidal or 
 concretionary forms in a state of solution hi water. It must, 
 therefore, have existed as a protoxide, and must have com- 
 bined with further oxygen or with carbonic acid subsequently. 
 When combined with the latter, it forms iron carbonate, and 
 this is one of the ores of iron. As an ore, it is siderite. It 
 possesses various degrees of purity. Often it occurs as a con- 
 cretion five to eight inches long, formed in the rock as I have 
 just explained. It may thus embrace much sand or clayey 
 matter, and this is the condition in which the siderite nodules 
 or " clay iron stones" are found in the coal measures and 
 other formations. 
 
 So you perceive that iron ores do not occur in proper 
 veins. They are isolated masses, or they are strata. They are 
 not mined out through shafts and drifts and chambers, like 
 the ores of gold and silver, but mostly in open excavations. 
 In Salisbury, Connecticut, the excavations extend into cav- 
 ernous, deranged stratified rocks, and many of the cavities are 
 lined with a black, polished coating of ore which when 
 scratched is yellow, and therefore limonite. This limonite has 
 been in solution. It has filtered through the interstices of 
 the formation. In many of the cavities are beautiful stalac- 
 titic forms hanging from the roof, or stretching from roof to 
 floor. These are much sought as fine specimens for the 
 cabinet. 
 
 The mean specific gravity of the whole earth is twice that 
 of the heaviest rocks. Is that due to compression of the in- 
 terior, or to the presence of some substance heavier than the 
 ordinary materials at the surface? Some have suggested the 
 probability that the earth's central mass is a vast ocean of 
 molten iron. It will be remembered, also, that iron is a chief 
 constituent in meteoric masses. 
 
130 WALKS AND TALKS. 
 
 . THE CRYSTALS OF S THE SEA. 
 
 SALT AND GYPSUM. 
 
 LOOK over a map of the Caspian Sea and notice on the 
 eastern side a roundish bay nearly cut off from the main 
 body. This is the Karaboghaz or Black Gulf. Though ap- 
 pearing so small, this bay is about ninety miles across. The 
 channel which connects it with the Caspian is only one hun- 
 dred and fifty yards broad and five feet in depth. The water 
 is shallow, though that in the central part of the Caspian 
 attains a depth of twenty-four hundred feet. Through 
 the strait connecting the Karaboghaz with the sea, a current 
 of water sets out from the Caspian at the rate of three miles 
 an hour. The inhabitants of the region fancy that an under- 
 ground passage exists from the Karaboghaz to the Persian 
 Gulf or the Aral Sea. This, however, is impossible, since the 
 Caspian is eighty-four feet lower than the ocean, and one 
 hundred and seventeen (some assert 250) feet lower than the 
 Aral. The vast volume of water discharged into the Kara- 
 boghaz is lost by evaporation from its surface. No large 
 rivers empty into it, while the climate is dry, and the summer 
 intensely hot. 
 
 The water of the Caspian, as you know, is salt. It has 
 been calculated that three hundred and fifty thousand tons of 
 salt are carried by the current into the Karaboghaz daily. 
 The process of evaporation must consequently increase the 
 saltness of the water in the bay ; and the great drain from the 
 sea must tend to diminish its saltness. Now, as a fact, the 
 Caspian possesses only about half the saltness of the open 
 ocean, while the Karaboghaz has become so intensely salt that 
 the animals which once inhabited its waters have disappeared. 
 In fact, the concentration has gone so far that layers of salt 
 are being deposited on the mud at the bottom. In all prob- 
 ability these processes will continue in the future, and it must 
 be anticipated that the salt deposit will increase in thickness 
 as long as this gulf exists. Should there be an elevation of 
 the strait connecting the gulf with the sea, the gulf would 
 
THE CRYSTALS OF THE SEA. 131 
 
 speedily dry up, and all the salt contained in its water would 
 be precipitated in a vast bed of rock-salt. Then, should a 
 depression of the isthmus connecting this low salt formation 
 with the sea take place, there would be a new influx of the 
 sea. The sediments of its waters would be deposited upon the 
 bed of rock-salt ; and new precipitations of salt would occur. 
 The site of the Karaboghaz would then be a great salt-bear- 
 ing formation, like those formed in ancient times in various 
 ages of the world. 
 
 On other portions of the Caspian shores, the process has 
 been brought nearly or quite to completion. On the penin- 
 sula Apsheron, on the west side nearly opposite the Kara- 
 boghaz, are ten salt lakes, in one of which, evaporation has 
 gone so far that ten thousand tons of salt are annually re- 
 moved from it. Again, in the neighborhood of Novo Pet- 
 rovsk, the deep indentation on the east shore was once a large 
 bay, which is now divided into a number of basins presenting 
 every degree of saline concentration. One of these still, occa- 
 sionally receives water from the sea, and has deposited on its 
 banks only a thin layer of salt. A second, still full of water, 
 has its bottom covered by a thick crust of rose-colored crys- 
 tals like a pavement of marble. A third exhibits a compact 
 mass of salt on which are pools of water, whose surface is 
 more than a yard below the level of the sea. A fourth has 
 lost all its water by evaporation, the stratum of salt left be- 
 hind being uncovered by sand. A similar concentration is 
 taking place in the Karasu, or long inlet setting southward 
 from the north-eastern extremity of the Caspian. 
 
 The whole Caspian is greatly dwarfed from its ancient 
 dimensions by the process of evaporation, and it would be 
 naturally expected that the salinity of the water would be 
 intensified, as in the Dead Sea, instead of diminished. The 
 intensification has really taken place, but, under such circum- 
 stances that only marginal portions have increased in sal tn ess, 
 while the main body has been weakened by the influx of the 
 great rivers Volga, Ural, Kuma and Terek. 
 
 This account of changes taking place on the borders of the 
 
132 WALKS AND TALKS. 
 
 Caspian, well illustrates, as I have long believed, the method 
 of accumulation of the great salt formations of geological 
 times. In western New York, in certain regions great beds 
 of rock salt may be reached by boring to a certain depth. 
 They lie underneath solid sheets of limestone and thick beds 
 of shale. In the vicinity of Goderich, Ontario, and also in 
 Michigan at sundry localities Marine City, St. Clair, Alpena 
 on the east shore, and Manistee, Muskegon and Ludington 
 on the west shore vast deposits of rock salt are found, at 
 depths from a thousand to two thousand feet. The best of 
 evidence exists that the salt bed is the same on opposite sides 
 of the state, and extends continuously under the state. This 
 is also, the formation which supplies brine for the works at 
 Syracuse. 
 
 Another salt formation occurs in Michigan, occupying a 
 higher geological position than that just mentioned. The 
 first is the Salina formation in the Upper Silurian (see Table, 
 p. 73) ; this is the Michigan Salt Group, in the Lower Car- 
 boniferous. From the last, the wonderful supplies of the 
 Saginaw valley are mostly obtained. From the Salina form- 
 ation the supplies eclipse even those of the upper group. At 
 Marine City, on the St. Clair river, a delightful steamboat 
 ride from Detroit, are works of astonishing magnitude and 
 productiveness. The great salt industry of Cheshire, England, 
 is supported by beds of rock salt sixty to a hundred feet thick, 
 and underlying strata of clay and gypsum, and having indu- 
 rated clays and gypseous beds underneath. Much of the salt 
 is mixed with earthy materials, and hence is redissolved in 
 sea-water, settled and re-evaporated. Other salt deposits of 
 world-wide celebrity occur in Poland, Austria, and Germany. 
 The boring at Stassfurt, Germany, penetrated 1,066 feet of 
 rock salt, and that at Sperenberg, 5,084 feet without reach- 
 ing the bottom. 
 
 It appears, therefore, that the evaporation of sea-water 
 has taken place on a large scale in various ages of the world. 
 In many localities the salt has been again dissolved by fresh 
 water from the surface, and porous formations underlying have 
 
THE CRYSTALS OF THE SEA. 133 
 
 become saturated with brine. This is the case with the Michi- 
 gan Salt Group and the Onondaga salines of New York, as 
 also those on the Kanawha and Ohio rivers. In some cases 
 the home rocks possess sufficient porosity to retain the brine. 
 In other localities the solid salt exists, but it is so mixed with 
 clay as to require redissolving and purification. This as I 
 said, is the case in Cheshire. In some countries, as in Poland 
 and Austria, great mines are excavated in immense salt forma- 
 tions. In Michigan the rock salt possesses great purity, but 
 it lies so deep that the expense of sinking and maintaining 
 shafts has so far, led to the expedient of dissolving the salt in 
 its place, and then pumping out the saturated brine. At 
 Marine City, water pumped from the St. Clair river is forced 
 down the bore-hole, where it dissolves the salt, and is then 
 forced out by the same process into great tanks, where the 
 brine settles, and then in other tanks undergoes evaporation 
 by means of heat from steam pipes immersed in the brine. 
 The precipitated salt is raked out by automatic rakes, allowed 
 to drain, then dried and barreled. At Syracuse and in the 
 Saginaw valley, the brine is pumped from the wells and set- 
 tled and evaporated. Formerly much evaporation was done 
 in kettles over a fire. More recently, pans and steam have 
 been employed. A large amount of salt is produced, especially 
 at Syracuse, by spontaneous evaporation in shallow vats ex- 
 posed to the sun and air, and covered in rainy weather, by 
 light roofs moved on rollers. 
 
 The natural brines of Saginaw and other regions contain 
 impurities. In the process of evaporation those least soluble 
 are first precipitated out, and then the other substances in the 
 inverse order of their solubility. Thus the brine, which is 
 limpid and sparkling on its escape from the earth, after ex- 
 posure to the air forms, by peroxidation of the iron (see Talk 
 XXII) a red deposit which is insoluble, and falls to the bot- 
 tom of the settling vat generally hastened by some coagulable 
 substance. When transferred to the kettles and heated, 
 gypsum is the first deposit, and this adheres firmly to the sur- 
 face. Next, common salt crystallizes out, which forms on the 
 
134 WALKS AND TALKS. 
 
 bottom and is raked from the kettle, drained and placed in 
 bins. The water remaining is called "bitterns," in conse- 
 quence of other bitter and nauseous substances still remaining. 
 Should the evaporation be further continued, Epsom salts 
 (magnesium sulphate) would be thrown down in needle-shaped 
 crystals. Finally, the chlorides of calcium and potassium 
 possess such affinity for water, that they could only be sepa- 
 rated completely by bringing the residue to a red heat. 
 
 This order of precipitation possesses much geological in- 
 terest. In some salt formations, as that of the Salina group, 
 the same order of succession has been noted. At the bottom 
 we find red ferruginous clays. Above are gypseous clays and 
 often, beds of pure gypsum. Next occurs brine or salt. 
 Above all are found limestones still retaining the needle-shaped 
 cavities from which the crystals of Epsom salt have been dis- 
 solved, or in which crystals of some other substance have been 
 deposited as pseudomorphs minerals having the crystalline 
 forms which characterize other minerals. This succession 
 observed in nature is a confirmation of the theory of origin of 
 salt formations by evaporation of gulfs and bays. It is evi- 
 dent, however, that such order of deposit can not generally be 
 observed as one single circuit ; because irregular irruptions of 
 sea-water, alternating with floods from land and periods of dry 
 weather, must break up any continuous succession from begin- 
 ning to end of the history of a salt basin, and must lead to 
 many repetitions of strata of the various kinds. This, how- 
 ever, is the fact universally observed, that all salt formations 
 are characterized by the presence of all or nearly all the sub- 
 stances found existing in sea-water. Gypsum, especially, is 
 always associated with brine and salt; and that is the reason 
 the two have to be discussed together. Other substances, 
 found equally in sea-water and natural brines, are magnesia, 
 potash, bromine, and iodine. 
 
LIQUID SUNLIGHT. 135 
 
 XXIV. LIQUID SUNI^IQHT. 
 
 PETROLEUM. 
 
 THE history of the search for native oil is romantic. 
 Known for ages, it remained a mere curiosity till 1859. Even 
 in America, where popular intelligence is supposed to utilize 
 every possible advantage, petroleum rose only to the import- 
 ance of a quack remedy for aches and other evils. But sud- 
 denly it assumed the scepter of king. It ruled the plans and 
 lives of thousands ; it sent men blindly and stupidly in herds, 
 to the forks of streams in search of imaginary "ranges" and 
 fanciful "oil belts." The smell of petroleum was a craze. 
 Men pursued it with the sound and fury of dogs on the track 
 of their prey. They lost their power of reasoning on the sub- 
 ject. They could not be convinced that mineral oil is a geo- 
 logical product, fixed in its relations to the earth and to the 
 strata, as unchangeably and as intelligibly as iron or salt. 
 They would not listen to the counsel of science. Every man 
 was confident in his self-wisdom, and never inquired on what 
 grounds he believed and acted as he did. Repudiating the 
 advice of those whose special business it was to know some- 
 thing on the subject, they preferred the dictates of their own 
 ignorance ; they went by the scent of the stuff; they were led 
 by the nose; they put their money in the ground with the 
 assurance of infallibility and many of them have kept it 
 there, as the souvenir of a happy intoxication. There was 
 oil millions of barrels of it ; and many investors were fortu- 
 nate if not wise; and many, though wise, were not fortunate. 
 
 It was a new situation. It must be confessed that geology 
 took up the subject as a novice; though with the great ad- 
 vantage of a knowledge of certain geological principles to 
 which the generation and accumulation of petroleum must 
 necessarily conform. But the geologist's inexperience in the 
 actual behavior of the product led to errors of judgment and 
 confessions of ignorance. Few geologists, however, manifested 
 that strength of confidence in opinions which is the character- 
 istic of weak or ignorant minds. Many, however, who ad- 
 
136 WALKS AND TALKS. 
 
 vertised themselves as geologists, were pretenders and quacks. 
 Recognized by the undisc rim mating as geologists, possessing 
 equal authority with scientific men who had earned reputa- 
 tions among their compeers, these geological quacks brought 
 discredit on science, and justified, to some extent, the contempt 
 of "practical men" who appreciated conclusions, but spurned 
 the reasoning which led to them. 
 
 Now, some of the scientific principles which must hold 
 true without any regard- to the particular causes and condi- 
 tions of oil-accumulation, are such as these : 1. Oil is not a 
 direct deposit from the sea ; it is the product of some changes 
 in substances which formed part of the ocean's sediments. 
 2. Being composed of carbon, hydrogen, and oxygen, it must 
 have originated from organic substances, either vegetable or 
 animal. 
 
 3. Being lighter than water, it must tend to rise through 
 the water which saturates all rocks, instead of sinking. The 
 source of the oil, therefore, could never be in any formation 
 situated at a higher level than the place of the oil. This is a 
 principle which the crazy crowd could never be taught. The 
 oil, for them, was always a "drip" from the Coal Measures. 
 
 4. A good " surface show" is not favorable, since it is only 
 caused by the escape and waste of the oil; while the thing 
 wanted is an accumulation or retention of the oil that is, an 
 absence of surface show. This the contemners of scientific 
 guidance could not understand. 
 
 5. There must consequently be an overlying stratum 
 which is impervious to oil, to prevent the product from rising 
 to the surface, to be wasted in a "surface show." If a fissure, 
 even, passes through this, the oil will escape. A bed of clay 
 or compact shale might serve as such a cover. Compact lime- 
 stone might serve ; but most limestones are too much shat- 
 tered. Indeed, shattered limestones, in some cases, serve as 
 reservoirs for the accumulation. 
 
 6. The accumulation of oil must be determined, among 
 other things, by the attitudes of the strata. The trends of " oil 
 territory " must conform to the trends of formations. The situ- 
 
LIQUID SUNLIGHT. 137 
 
 ations of creeks at the surface could have no bearing on the 
 underground distribution of petroleum. The junction of two 
 streams and the location of a sand-flat could sustain no rela- 
 tion to strata three or four hundred feet beneath. Whether 
 the situation were in a ravine or on the upland could make 
 no difference except in the depth of the boring. The notion 
 of "ranges" and "lines" in the distribution of productive 
 territory was illusory ; since this is determined by the direc- 
 tion, the length, and the breadth of the formations which fur- 
 nish the requisite conditions. 
 
 7. Petroleum is not confined to any particular formation. 
 For many years it has been known in limited quantities, from 
 the Eozoic gneisses to the Tertiary. The assumption was mis- 
 leading, therefore, that every oil region must be supplied under 
 the same stratigraphical and topographical conditions as Ven- 
 ango county, Pennsylvania. It was a matter of scientific cer- 
 tainty that another region might be fed from strata of a dif- 
 ferent geological age, of a different lithological constitution, 
 dipping in a different direction, trending to other points of 
 the compass, and overlaid by different topographical features 
 at the surface. 
 
 All these principles, I have said, were known to science, 
 and secured to the scientific man, certain important advan- 
 tages in arriving at judgments concerning prospects of success 
 in a proposed enterprise. All of these principles were disre- 
 garded by a majority of the "oil-prospectors." Some men 
 under pay from capitalists, even resorted to the witch-hazel 
 fork in quest of knowledge on which capital might venture 
 investment. 
 
 Let me now add some principles which experience and ob- 
 servation have pretty well established, and you will have the 
 whole philosophy of oil-finding and oil production. It is gen- 
 erally admitted that the porous stratum in which oil accumu- 
 lates must have an arched or anticlinal form. Otherwise, the 
 oil will spread laterally to an indefinite distance, and no local 
 accumulation will take place. On the contrary, the oil will 
 somewhere find an outlet to the surface. 
 
 12 
 
138 "WALKS AND TALKS. 
 
 Another doctrine generally accepted is the vegetable origin 
 of the great supplies possessing commercial importance. It is 
 admitted that animal remains may be a source of petroleum 
 to a small amount. 
 
 Again, it has been observed that every great oil-containing 
 reservoir has below it not always immediately below a for- 
 mation of the nature known as black bituminous shale. This 
 is soft, easily cut with a knife, and contains a large amount 
 of vegetable matter. Such shales are generally thought to 
 contain quantities of remains of sea-weeds. If so, they exist 
 in a comminuted and obscure state. 
 
 Probably a majority of geologists entertain the opinion 
 that petroleum is produced from these black shales by a slow 
 spontaneous distillation, through the action of the heat in the 
 rocks. By artificial distillation, oil is readily obtained from 
 them, and little doubt is entertained that at a comparatively 
 low temperature, a slow natural distillation proceeds. 
 
 Observation has shown that while black shales manifest a 
 predisposition to the production of oil, pure vegetable deposits 
 are more fixed. Thus, from proper coal-beds no oil proceeds ; 
 but from cannel coal and coaly shales oil is spontaneously 
 evolved, as it also is from the black shales where the vegeta- 
 ble matter has not attained a coaly condition. The mixture 
 of argillaceous matter with the vegetable material seems to 
 favor the oil-making process. 
 
 Natural gas has an origin very similar to that of petro- 
 leum. The inflammable gas now so extensively employed as a 
 substitute for coal, is also composed, like petroleum, of car- 
 bon and hydrogen, but with a larger proportion of hydrogen. 
 It must be derived, in a similar way, from a similar source. 
 Petroleum, in fact, is generally associated with gas. It seems 
 to be composed of the heavier and more fixed compounds of 
 carbon and hydrogen containing much carbon, while gas is 
 a lighter compound with more hydrogen. Petroleum, how- 
 ever, is not a simple compound of definite composition, but a 
 mixture, apparently of many compounds the more fixed, like 
 asphalt and paraffine, being dissolved in the fluids kerosene. 
 
LIQUID SUNLIGHT. 139 
 
 naphtha, and others. It is evident that natural gas may wan- 
 der farther away than oil from the formation in which it origi- 
 nates ; and hence there may be more difficulty in tracing it 
 to its real source. It may become widely separated from ap- 
 parent connection with oil. It may also be distilled from 
 shales not possessing the requisite richness to afford oil. 
 Hence, in some regions, as Fremont, Cleveland, and other 
 localities in northern Ohio, it issues from Cambrian strata 
 which furnish no indications of oil. In western Pennsyl- 
 vania, within the Coal Measures, the great supplies of 
 gas are yielded probably, by the same formations as sup- 
 ply petroleum. This, however, is a question still under 
 investigation. 
 
 Now let us look into the relations of things in some of the 
 principal oil-producing regions. The most famous is that of 
 northwestern Pennsylvania. The surface rocks are Coal 
 Measures or Lower Carboniferous Sandstones (Waverly or 
 Catskill sandstones) or Chemung sandstones according to 
 the locality. The oil is found accumulated in the sandstones ; 
 but its source is believed to be the Genesee Black Shale, 
 near the top of the Hamilton Group (See Table, page 73.) 
 There are in all productive situations, shaly strata also, 
 above the sandstone reservoir, which prevent the oil from 
 escaping to the surface. The situations are similar in eastern 
 Ohio and southern New York. 
 
 In Ontario are two kinds of oil, and two different reser- 
 voirs. The thick lubricating oil accumulates in a gravel bed 
 at the bottom of the Drift, and is confined by the clay sheets 
 of the overlying Drift. Its source is probably the Genesee 
 Shale, which immediately underlies, but thins out a half 
 mile further east. The more abundant petroleum is found 
 stored in fissures and cavities of the Hamilton limestone; 
 and its source is probably the black Marcellus shale next 
 below the limestone. These cavities often contain water un- 
 der the oil, and gas above it. If the auger enters the upper 
 part, gas escapes at first, but when this is exhausted, oil may 
 be pumped. When the oil is exhausted, water follows. If the 
 
140 WALKS AND TALKS. 
 
 auger enter below the surface of the oil, the reaction of the 
 gas forces the oil to the surface, and a "flowing well" 
 exists. When the oil becomes lowered to the place of 
 the perforation, gas escapes till the pressure is relieved. Then, 
 if any oil remains, it may be pumped. Lastly, the water 
 may be pumped. If the auger enters the cavity below the 
 surface of the water, the reaction of the gas forces first water 
 to the mouth of the well ; then when the bottom of the oil 
 is lowered to the orifice, oil is forced out till its surface sub- 
 sides to the orifice, when, finally, the gas escapes. No oil 
 now remains in the cavity. 
 
 In California an oil-producing shale extends through the 
 Eocene (Tertiary) of the Coast Ranges; but south of San 
 Francisco these strata mostly stand on edge, and most of the 
 fluid oil has escaped, leaving large quantities of tarry as- 
 phaltum, which hardens on exposure to the air. North of 
 San Francisco, however, these shales are horizontal, and oil 
 has accumulated in considerable quantities. But the chief sup- 
 ply of petroleum in California is found in the less disturbed 
 regions south of San Francisco, chiefly in Los Angeles and 
 Ventura counties. The total product of the state in 1884 
 was 262,000 barrels. 
 
 In foreign counties, the most productive territory is the 
 Baku region in Russia, near where the Caucasus abuts 
 against the Caspian. Here is an area of 14,000 square miles 
 which is producing, under treatment assimilated to that em- 
 ployed in America, quantities which promise to interfere se- 
 riously with the export of American oil. Six hundred wells 
 have been bored, and one spouting well is represented to 
 have produced 50,000 barrels a day. The most copious Penn- 
 sylvania well flowed 9,000 barrels a day, and the most pro- 
 ductive Canadian well, 7,500 barrels. 
 
GASEOUS SUNLIGHT. 141 
 
 XXV. GASKOUS SUNLIQHT. 
 
 NATURAL GAS ITS WONDERS AND ITS GEOLOGY. 
 
 ILLUMINATING and Heating Gas is one of the products of 
 the earth. Its escape is a geological phenomenon. Its pres- 
 sure, its volume, its composition, its permanence, are facts 
 from which the geologist deduces past conditions in the world's 
 history. It was stated in the last talk that its origin is un- 
 doubtedly similar to that of oil, and that oil is chiefly the 
 product of the distillation of shales charged with vegetable 
 matter probably ancient sea-weeds which grew in veritable 
 " Sargosso Seas." As sun-light is the active agent in vegeta- 
 ble growth, a stem or a leaf is simply a body of transformed 
 sun-light. When imbedded in the rocks it is strictly and lit- 
 erally fossil sun-light. In petroleum, ancient sun-light is pre- 
 served in liquid form ; in natural gas it is gaseous. 
 
 The escape of burning gas from the earth has been ob- 
 served for ages. For more than fifty years, the gas escaping 
 with the brine from the wells of the Kanawha Valley, West 
 Virginia, has been employed in the evaporation of the brine. 
 It has long been utilized in some salt mines where it escapes 
 through crevices. In a similar way, it enters coal mines, and 
 is known to miners as fire damp, since, mixed with a certain 
 proportion of atmospheric air, it becomes violently explosive. 
 The Chinese have for centuries, employed natural gas for 
 lighting and heating. On the Cumberland, in Kentucky, 
 gas accumulates in underground reservoirs, and the elastic 
 pressure is sometimes attended by explosions, constituting 
 earthquakes of local extent, and lending some plausibility to 
 the ancient theory of those phenomena. At Fredonia, New 
 York, are gas emissions which have attracted attention for 
 many years, and have long been utilized for lighting and 
 heating. A gas spring was discovered here in 1821. The 
 gas at that time accumulated was used for lighting a mill and 
 several stores. It was also introduced into a few public build- 
 ings, and was brought to the attention of Lafayette when he 
 
142 WALKS AND TALKS. 
 
 passed through the village in 1824. Subsequently, a shaft 
 was sunk, and sufficient gas concentrated to supply thirty 
 burners. Thirty-seven years afterward, another shaft was 
 sunk thirty feet, and two borings were made one to 150 feet. 
 In 1858, two thousand cubic feet of gas were delivered daily 
 through the village. 
 
 During the years of the great oil excitement, from 1860 
 to 1870, many of the borings for oil reached only gas. In 
 Knox county, Ohio, in 1860, two wells were sunk for oil. 
 In both, streams of salt water were intercepted, and, at about 
 six hundred feet, an immense reservoir of gas was struck. 
 The gas ejected the water with great violence. The first well 
 was bored in the winter, and the water soon covered the derrick 
 with ice, forming a kind of chimney sixty feet in height. 
 Through this, the water was thrown, at intervals of about one 
 minute, to double that height, or 120 feet. After the water, 
 and with it, came a great rush of gas, which continued until 
 the pressure below was relieved, when the water again began 
 to accumulate, and was again ejected. The process was en- 
 tirely analogous to the action of the geysers described in Talk 
 XIV. In the Knox county well, gas took the place of steam 
 in the geyser. When the derrick was covered with ice, the 
 gas escaping from the well was frequently ignited, and the 
 effect, especially at night, of this fountain of mingled fire and 
 water, shooting up to the height of one hundred and twenty 
 feet, through a great transparent and illuminated chimney, is 
 said to have been indescribably magnificent. 
 
 When I visited the spot, in 1866, a two-inch gas pipe had 
 been fixed in the orifice of the second well, and the gas was 
 escaping with a power and volume which were startling. The 
 sound could be heard for a quarter of a mile. The pressure 
 was two hundred and sixty-two pounds to the square inch, 
 as reported by Mr. Peter Neff. The ignited jet formed a 
 flame twenty feet in length, and as large around as a hogshead. 
 It was an exciting spectacle. If the stop-cock were closed a 
 few minutes and again opened, the accumulated pressure gave 
 a volume of flame as large as a house. The supply of gas 
 
GASEOUS SUNLIGHT. 143 
 
 here was sufficient to illuminate a large city. Ten years after- 
 ward, personal information from Mr. Neff, under whose direc- 
 tion the work had been done, assured me that these wells 
 continued to "blow," and he was then manufacturing from 
 the gas a refined quality of lampblack. 
 
 In Michigan, certain parts of Wayne, Oakland, and Ma- 
 comb counties appear to be underlaid by considerable reser- 
 voirs of gas. In 1875, a gas well was struck three miles west 
 of Royal Oak, at the depth of a hundred feet. In 1877, a 
 well eight miles southeast of the village, at the depth of one 
 hundred and fifty feet, reached confined gas which threw the 
 tools into the air. It is said that much sand escaped, and a 
 stone weighing "several" pounds was thrown over a barn 
 " forty rods distant." The well was subsequently filled evi- 
 dently after the high pressure of the gas had subsided. In 
 1879, at a place five miles northeast of the same village, a 
 well bored one hundred feet secured a supply of gas which 
 has since been used for illuminating purposes. Three miles 
 south of the village, a powerful explosion revealed the uncov- 
 ering of a gas reservoir in 1880. After burning two years, 
 two other gas wells were bored, and the united illumination 
 rendered newspaper print legible at night, at the distance of 
 one hundred yards. In 1883, a gas vein was reached at 
 ninety-eight feet, which furnished a flame twenty feet high. 
 In 1884, on deepening this well, water was found, and addi- 
 tional gas which threw the water to the height of twenty feet. 
 Many other occurrences of a similar nature have been known 
 in this part of Michigan. 
 
 At West Bloomfield, New York, a well bored five hun- 
 dred feet emitted gas with great force. At Erie, Pennsyl- 
 vania, Conneaut, Painesville, Cleveland, and Fremont in 
 Ohio, a number of wells have been successfully bored. At 
 Buffalo, New York, gas with a pressure of one hundred and 
 thirty-one pounds to the square inch issued from a well six 
 hundred and forty feet deep. At Cumberland, Maryland, a 
 gas well burned for two years. Some six miles east of Crab 
 Orchard, Kentucky, is a burning spring, the water in which 
 
144 WALKS AND TALKS. 
 
 is in a constant state of ebullition from the escape of gas. 
 "Kegularly every day/' says J. F. Henry, "between four 
 and five o'clock in the afternoon, it overflows ; a large quan- 
 tity of gas is liberated, and if a torch is applied, a flame re- 
 sults." At Fairview, Pennsylvania, a well drilled for oil, in 
 1870, to the depth of one thousand three hundred and thirty- 
 five feet, yielded an immense volume of gas through a six- 
 inch pipe, with so much noise as to be heard for a distance of 
 two miles. The pressure was eighty pounds to the square 
 inch. The gas was employed in establishments in Fairview, 
 Petrolia, Kerns City, and Argyle, besides furnishing fuel used 
 in drilling some forty other wells. In the same year, a well 
 bored near Titusville discharged four million cubic feet per 
 day. At East Sandy, in the same oil district, a gas well 
 struck in 1869 resisted all efforts to extinguish its burning. 
 "It roared like a cataract and could be heard for miles." 
 
 Within a couple of years, large supplies of gas have been 
 obtained in northern Ohio, by boring down to the Trenton 
 Limestone at least, into the Cambrian ; for some doubt exists 
 as to the precise formation. It is announced (January, 1886,) 
 that Fremont, Ohio, has reached a supply of two million feet 
 daily. It is also reported that gas and oil have been obtained 
 at Lima, Ohio, at the depth of one thousand two hundred 
 and fifty-one feet. The gas produces a jet of flame thirty 
 feet high. 
 
 The vicinity of Pittsburgh, however, surpasses all other 
 regions in abundance of gas-supply. The surrounding coun- 
 try seems to be underlaid by reservoirs of incredible capacity. 
 These, or some of these, have been tapped, and the product 
 has come into extensive use in furnace and other operations. 
 Mr. William Metcalf, writing in November, 1884, said : " An 
 observer standing on a hill-top in Allegheny township, West- 
 moreland county say about three miles southeast of the con- 
 fluence of the Allegheny and Kiskeminetas rivers can see, 
 on a dark night, on the northwestern horizon, the reflection of 
 the lights from the Butler county wells; to the north, the 
 lights from the wells in the direction of Kittan'ing; to the 
 
GASEOUS SUNLIGHT. 145 
 
 northeast, the Leachburg and Apollo wells; to the southeast, 
 the Murraysville wells, and to the southwest, the lights of the 
 Tarentum wells. Off in Washington county, and down to- 
 ward Steubenville, there are other wells, while at Hulton, in 
 Pittsburgh, in the east end at Soho, at Brownstown, at Sligo 
 and in Bayardstown, there are wells upon wells, roarers and 
 gushers. Some of these wells give out their gas at an enor- 
 mous pressure. A gauge on a six-inch pipe situated some 
 miles from the wells, registered one hundred and twenty 
 pounds to the square inch, and the noise of the rushing gas 
 indicated that the gauge was about right." 
 
 Two of the most prolific of these wells, the Burns and the 
 Delamater, have been described by the late Professor J. Law- 
 rence Smith. " These are separated by at least half a mile, 
 and are located in Butler county, seven miles north-east of 
 Butler, and about fifteen miles from the Harney wells, of 
 which the gas is conducted to Pittsburg. The two wells are 
 located about thirty miles in a straight line from Pittsburg. 
 Their depth is about one thousand six hundred feet, down to 
 the fourth sand stratum so well known, at least by name, to 
 those engaged in the petroleum production '. The Burns, it is 
 believed, has never yielded oil; but the Delamater first 
 carried to the third sand layer (the oil men mean sandstone 
 when they say 'sand'), was a petroleum well at one thou- 
 sand six hundred feet. Sunk afterward to the fourth stratum, 
 it gave gas at such a pressure that the tools, of one thou- 
 sand seven hundred and sixty pounds weight, could be with- 
 drawn by hand. Each well is five and five-eighths inches in 
 diameter." 
 
 The Delamater is the more remarkable. It furnishes light 
 and fuel to all the vicinity, including the village of Saint Joe. 
 It is situated in a valley surrounded by high mountains, which 
 reflect and concentrate the light of the ignited gas. Many 
 conduits start from the well ; one leads the gas directly to the 
 cylinder of a strong motor, which, by its pressure, acquires a 
 prodigious velocity. Another pipe feeds a flame capable of 
 reducing as much iron ore as half the furnaces of Pittsburgh. 
 
 13 
 
146 WALKS AND TALKS. 
 
 At sixty-four feet distant is the principal escape orifice of the 
 well. From a tube three inches in diameter, a column of 
 fire forty feet high shoots forth with a roar that fairly makes 
 the hills tremble. During a calm night the noise can be heard 
 at a distance of fifteen miles. At four miles, the sound re- 
 sembles that of a railroad train crossing a bridge near at 
 hand, and finally, as the escape orifice is reached, the roar is 
 like that of a thousand locomotives blowing off steam together. 
 At the well, in a tube of five and five-eighths inches, the pres- 
 sure is about one hundred pounds per square inch ; in a tube 
 of two inches, in which the gas is led to Freeport, fifteen 
 miles distant, the pressure is one hundred and twenty-five 
 pounds. The ascending velocity is one thousand seven hun- 
 dred feet per second, and if this be multiplied by the area of 
 the tube, 24.7 square inches, a yield of two hundred and 
 eighty-nine cubic feet per second, or about one million cubic 
 feet per hour, is determined. This is one thousand four hun- 
 dred and eight tons of gas daily. This, for heating purposes, 
 is estimated as equivalent to two thousand tons of bitumi- 
 nous coal. 
 
 A year ago, the daily consumption of natural gas for fuel 
 purposes in the city of Pittsburgh, was fifteen to twenty mill- 
 ion cubic feet. The Consolidated Fuel Gas and Penn Fuel 
 companies were delivering from Murraysville, through four 
 lines of pipe, ten million cubic feet per day. Another line 
 then building was intended to increase the flow to fifteen or 
 seventeen million cubic feet. The Washington Gas company 
 had a pipe line twenty miles in length from the famous Mc- 
 Gingan well in Washington County. To this they were add- 
 ing an eight-inch line, which would increase their capacity to 
 five million feet. The Philadelphia company was then con- 
 structing three gigantic lines one from Murraysville, another 
 from Tarentum, and a third from the famous Westinghouse 
 wells at Homewood, within the city limits. These lines would 
 have a combined capacity of about thirty million feet per 
 day. The Carpenter company were arranging to deliver four 
 million, and the Chambers company three million cubic feet. 
 
GASEOUS SUNLIGHT. 147 
 
 Thus the enormous aggregate of sixty million feet was pro- 
 vided for; and even this would not exhaust the supply 
 already existing. Sixty-five to seventy million cubic feet 
 were daily wasting in the Murraysville district alone. 
 
 The aggregate wastage as indicated by data still more re- 
 cent, surpasses all which would be suspected from the facts 
 given above. It is alleged (March, 1886), that in the entire 
 gas field about Pittsburgh, two hundred and sixty-four million 
 cubic feet of gas are daily wasted. One thousand cubic feet 
 are estimated to equal one bushel of coal in heating property. 
 This would make an equivalent of two hundred and sixty- 
 four thousand bushels of coal burned in the air each day. A 
 miner can, on. an average, dig seventy bushels of coal a day. 
 The waste then, would be, in round numbers, equal to the 
 daily work of thirty-eight hundred miners or about the whole 
 number employed in the Pittsburgh district. 
 
 This gas is a complex mixture of hydrocarbons. It di 
 fers from coal-gas, as also from gas made from petroleum. Its 
 main ingredient is "Marsh gas," which, next to hydrogen, 
 is the lightest substance known, consisting of seventy-five per 
 cent of carbon and twenty-five per cent of hydrogen, and hav- 
 ing a specific gravity of 0.5576, that of air being unity. The 
 mixed natural gas has a specific gravity ranging from 0.51 to 
 0.7. That supplied to Pittsburg may be averaged at 0.6, 
 from which it would appear that the gas for which provision 
 was making in 1884, was equivalent to about forty-nine hun- 
 dred tons of bituminous coal in heating capacity. 
 
 For heating purposes, natural gas excels coal gas thirty- 
 three and one-third per cent. Used in the crude way twenty 
 cubic feet of gas equal one pound of coal. Used in the ordi- 
 nary way, 11.29 cubic feet equal one pound or coal. Used 
 in the most economical way, 8.92 cubic feet equal one pound 
 of coal. For illuminating purposes it possesses only half the 
 value of good coal gas; although it has been asserted of 
 the Fredonia gas that it equals coal gas in respect to intensity 
 of light, and is consumed but half as fast. 
 
 The industrial changes effected in the city of Pittsburgh by 
 
148 WALKS AND TALKS. 
 
 the use of natural gas, are of a revolutionary character. In 
 the city and surrounding country, not less than ten million 
 dollars have been invested within a year, said a writer in 
 1884. " A year ago the business was insignificant; to-day, it 
 ranks in importance with the iron, steel, glass, and coal inter- 
 ests of western Pennsylvania. There are at present ten iron 
 and steel mills in this city using this gas in their puddling 
 furnaces and under their boilers ; a dozen more are busy mak- 
 ing arrangements for its introduction, and almost every manu- 
 facturing firm using steam is awaiting the completion of the 
 necessary pipe lines. Six glass factories in the city, and seven 
 others in the immediate vicinity are using it. Every brewer 
 in the city uses it. Two of the largest hotels use it exclu- 
 sively for cooking purposes. For general household use, on 
 account of its cheapness, cleanliness, and convenience of ap- 
 plication, it has no rival." 
 
 The city of Buffalo is also said to be laying pipe lines for 
 gas from the Pennsylvania gas districts. 
 
 Our modern forests are the chief producers of fuel in 
 human times. The sea supports a vast amount of vegetation ; 
 but we have not learned how to apply it to the production of 
 heat. Yet, strange as it seems, the sea-weeds which waved 
 their graceful fronds in the oceans of millions of years ago, 
 are smelting the iron for the pipes destined to bring their 
 transformed constituents to the sites of gigantic industries, 
 and warming the dwellings of the populations which con- 
 duct them. 
 
 Will these marvelous supplies hold out? That is the 
 question which the owners of the millions invested are 
 anxiously asking. Probably, as has been proved with petro- 
 leum, particular wells will gradually diminish in supply; 
 many will cease to yield ; some will continue indefinitely. 
 But probably, also, as in the case of petroleum, new supplies 
 will be discovered, and even increasing demands will be met 
 for many years in the future. 
 
SOLIDIFIED SUNLIGHT. 149 
 
 XXVI. SOLIDIFIED 
 
 COAL AND COAL-BEDS. 
 
 I SIT by my genial grate, this pinching winter evening, 
 and watch the play of the flames which leap from the coal 
 and play with the draughts of air passing up the chimney. 
 Here is comfort here is peace. How the fierce wind howls 
 about the windows while I enjoy this life-sustaining warmth. 
 Curious, is this coal this combustible rock, wonderful, and 
 abounding in suggestions. This warmth is yielded by com- 
 bustion. This rock burns up. That which burns up is essen- 
 tially carbon, or a hydrocarbon. It is so with petroleum ; it 
 is so with gas; it is so with coal. The source of uncombined 
 carbon is in vegetation. Our carbonates, like limestone, con- 
 tain carbon ; but it is combined with oxygen ; it is already 
 appropriated, not free not in a condition to be burned. The 
 coal must be composed of free carbon, to a large extent 
 mingled, probably with some hydrocarbon. Carbon, as we see 
 in charcoal, burns without any brilliant flame, and without 
 smoke. Hydrocarbon, as we see in kerosene and illuminating 
 gas, burns with a bright flame. The coal in the grate emits a 
 moderately brilliant flame. It is a mass of carbon saturated with 
 some liquid or gaseous, or perhaps, bituminous, hydrocarbon. 
 In any event, we are induced to trace its carbon to a vege- 
 table origin. 
 
 Now, if we look over a pile of coal we shall probably de- 
 tect some indications of vegetable tissue. In some coals of 
 the soft kind, we may find masses of woody fiber black and 
 brilliant, like some charcoal. In some of the shale attached 
 to pieces of coal, or mingled with the coal, are some impres- 
 sions like fern-fronds. If we go to the mines, we even dis- 
 cover stems of moderate sized trees imbedded in the shales 
 above the coal, and occasionally in the coal itself. Again, if 
 we prepare exceedingly thin slices of coal, and remove the 
 black matter by proper treatment, we may detect, by means 
 of the microscope, minute structures, such as belong to vege- 
 tation. All these circumstances then, conspire to convince us 
 
150 WALKS AND TALKS. 
 
 that the coal is of vegetable origin, and much of it from tree- 
 like vegetation. With other observations we detect, many 
 times, innumerable spores scattered through the coal. These 
 are cells produced by vegetation which is flowerless. They 
 answer for the fruit, but are not fruit, as the term is usually 
 employed. The coal vegetation, therefore, was without flow- 
 ers or fruits. Much of it, as we readily discover, was of the 
 nature of ferns some of them tree-ferns, such as grow in our 
 times, in some tropical regions. If we were to search further 
 we should find traces of vegetation resembling our Horsetails 
 and Ground Pines. So we may regard ourselves quite justi- 
 fied in concluding that the coal which blazes and cheers on 
 the grate, was once in the condition of a flowerless tree, rooted 
 in an ancient soil, spreading its green fronds to the sunlight, 
 decomposing the carbonic acid of the atmosphere, fixing the 
 carbon in its own tissues, and setting oxygen free. 
 
 So, the sun was shining in the heavens so long a time ago. 
 The plans of vegetable structure were in existence, and the 
 forces of vegetable growth. How long have those plans en- 
 dured ! How imperishable are the thoughts embodied in those 
 plans, and expressed by them ! The tree stood upright in the 
 soil ; it drank in water by its roots, and bathed its foliage in 
 the primeval air. It built its stem and fronds with fibers and 
 cells like the modern fern. The sun stimulated it into action. 
 The sun's warmth imparted strength to discharge its functions. 
 The sun's emanations of light and heat became transformed 
 into stem and frond and tissue. Whatever vicissitudes that 
 growth may since have undergone, the same eliminated carbon 
 is there ; much of the same tissue form is there; it is the same 
 transformed sunlight that it was millions of years ago. It is 
 ancient' sunlight that has been locked up like a treasure and 
 buried in the earth for ages. Here, in this flame, the tissue- 
 substance goes back to its primeval condition it becomes 
 again carbonic acid, and mingles again in the atmosphere from 
 which it was selected. Here, in this flame, the old warmth 
 reappears; it is the warmth of the sun which shone in the 
 Carboniferous Age. Here, in this flame, the old sunlight is 
 
SOLIDIFIED SUNLIGHT. 151 
 
 regenerated ; this is the very sunlight which became latent in 
 vegetable cells so long ago. It is locked-up sunlight set free 
 after a long imprisonment. It is the wasting sunlight of an 
 age when its blessings were not appreciated, packed away and 
 preserved to an age when man should dwell on the earth to 
 appreciate its uses and make it an agent of exquisite comfort 
 and high civilization. 
 
 There are several varieties of coal ; let us look them over. 
 Perhaps you will smile when I tell you that the plumbago of 
 your pencil is essentially carbon. So it is. All your pencil- 
 ings are strictly " charcoal sketches." We can take common 
 coal and by subjecting it to pressure and heat while excluded 
 from the air, convert it into something much like plumbago. 
 It often occurs in iron-furnaces. This is sometimes called 
 black lead ; but it contains no lead ; its more appropriate name 
 is graphite. It is found among the metamorphic rocks. 
 Whatever it was, it has been pressed and baked and boiled 
 through the same processes which have so transformed the 
 original Eozoic sediments. Since graphite can be prepared 
 from coal, we may safely assume that graphite is only meta- 
 morphic coal. Indeed, there are regions where graphite occurs 
 in the same formation which in other regions we know as 
 Coal Measures. But the strata are all metamorphic. Most 
 graphite, however, belongs to a remoter geological age. We 
 find it in Vermont and most of the New England States ; 
 also in northern New York and many other American and 
 foreign localities. It can only be burned at a high tem- 
 perature. 
 
 Next in respect to hardness and difficulty of combus- 
 tion is anthracite. This breaks in irregular lumps, with shin- 
 ing surfaces, and burns with only a feeble bluish flame. It 
 has a relatively high specific gravity, and furnishes more heat 
 per ton than any other species of coal. Anthracite is found 
 in situations where it appears to have been subjected to a 
 baking and hardening process which has driven off most of 
 the volatile hydrocarbons found in other coals. In the United 
 States, south-eastern Pennsylvania is the chief anthracite 
 
152 WALKS AND TALKS. 
 
 region. It has afforded an enormous quantity, and some of the 
 best varieties are said to be about worked out. 
 
 The other varieties of coal are bituminous. That is, they 
 contain hydrocarbons partly of the nature of bitumen. But 
 the term as a designation for a variety is restricted to the black 
 coals occurring in the region east of the Rocky mountains, 
 chiefly in the Palaeozoic System. In structure they are dis- 
 tinctly stratified sometimes with films of earthy matter 
 between the laminae. They are apt to break in flattish or thin 
 fragments, and they possess an earthy or resinous luster. 
 They burn with much bright flame which arises from the 
 hydrocarbons expelled and ignited. These coals are the source 
 of the illuminating gas of our cities. 
 
 From the typical bituminous coals we may separate the 
 Cannd Coals. These have an earthy luster, a fine compact 
 constitution, and are often thick bedded, with only obscure 
 stratification within the bed. They burn freely and brightly 
 when rich, and were used in the earliest manufacture of 
 illuminating gas and kerosene, or "coal oil." This manu- 
 facture had attained a prosperous stage of development when 
 the discovery of the large supplies of petroleum caused its 
 ruin. Cannel coal has no standard degree of purity. It 
 consists of carbonaceous and aluminous particles mixed in 
 varying proportions. It degenerates, on one hand, to a mere 
 black shale, and on the other, attains a state in which it is 
 almost free from earthy admixture. 
 
 Among the typical bituminous coals, we distinguish the 
 caldng and the non-caking. The former when ignited, seem to 
 fry with an exudation of a fluid bitumen, which evolves much 
 gas and hardens into a crust somewhat impervious to the air, 
 and thus obstructing the draft. The latter burn freely, with- 
 out an incrustation. 
 
 Besides the Paleozoic bituminous coals we find excellent 
 Mesozoic bituminous coals. These are solid, but less valuable 
 than the others ; though they are a boon to many regions 
 otherwise scantily supplied with fuel. Of this kind is the coal 
 mined near Richmond, Virginia, and in the Deep river 
 
SOLIDIFIED SUNLIGHT. 153 
 
 region of North Carolina ; also the excellent coal of Wyoming 
 Territory, and that of similar excellence in Washington Terri- 
 tory, in the Cascade mountains. The latter exists in great 
 abundance and of several varieties, one of which has the ap- 
 pearance of anthracite. It is widely exported to San Fran- 
 cisco and the Hawaiian islands. 
 
 Brown Coal is of Csenozoic age. It is next in order of 
 hardness and value. It varies, however, from a variety quite 
 firm and compact, with a blackish color, to varieties of brown 
 color and composed distinctly of vegetable fragments. 
 
 Peat is a vegetable accumulation formed at the present 
 surface, from mosses, leaves, and sticks, and is not yet consoli- 
 dated into the condition of a coal. It is used, however, 
 extensively as a fuel, especially on the continent of Europe, 
 where the traveler may see it cut out in blocks and piled up 
 like bricks drying in the sun. The city of Paris is warmed 
 chiefly by peat. Many efforts have been made in America to 
 reduce peat to a cheap and efficient fuel ; but for the present, 
 it is unable to compete with our other natural combustibles. 
 
 Coal occurs in strata not in veins interbedded with sedi- 
 mentary rocks. Shales, clays, and sandstones exist extensively 
 in Coal Measures ; and in some regions, limestones are inter- 
 stratified. The latter contain fossil shells, and are manifestly 
 of marine origin. The coal must have been produced on the 
 land. Some of the .clays are apparently the soil in which 
 the vegetation grew, since the roots are found extending into 
 them. The shales were deposited in quiet, muddy waters, 
 within easy reach of the products of the land, since they con- 
 tain immense quantities of fronds and other vegetable matters, 
 generally in a fine state of preservation. 
 
 In regions somewhat disturbed, like Pennsylvania, the 
 strata of coal make outcrops like limestones, shales, and sand- 
 stones. Mining is then prosecuted from the "crop" by 
 carrying an excavation or drift along the slope of the coal 
 stratum. If possible, the place is so selected that the slope 
 may ascend from the mouth, so that the water reached may 
 flow out spontaneously. If this is not practicable, then pump- 
 
154 WALKS AND TALKS. 
 
 ing must be resorted to, and this sometimes becomes enor- 
 mously expensive. In regions where the strata repose in 
 nearly horizontal positions, the underlying coal beds are 
 reached through vertical shafts. In such cases, pumping 
 machinery is essential. Not unfrequently, one shaft is extended 
 down to a second or third bed of coal. In any case, after the 
 coal is reached, chambers or galleries are excavated in rectan- 
 gular directions in the bed. The roof is supported by large 
 blocks of coal left undisturbed. After most of the coal has 
 been thus removed, the supporting blocks are worked out suc- 
 cessively, and the roof of the mine may be permitted to 
 fall in. 
 
 AMONG THE FOSSILS. 
 
 XXVII. MONSTERS OF* A. BURIKD WORL,D. 
 
 EXTINCT QUATERNARY MAMMALS. 
 
 "Ms. JOHN SMITH, of the town of Sharon, in digging a 
 ditch to drain a swamp on his farm, exhumed some very large 
 bones which must have lain buried for many thousand years. 
 They appear to be the bones of a giant. They will be offered 
 to the University for sale." 
 
 "Mr. Peter Jones discovered last week in a peat bed, a 
 nearly complete skeleton of some antediluvian monster. Mr. 
 Jones will have the skeleton set up as soon as possible, and 
 will then start on a tour of exhibition. He feels confident 
 there is a fortune in these bones." 
 
 The above are samples of paragraphs frequently appearing 
 in the newspapers. They indicate that the peat bogs of our 
 country contain many relics of beings no longer in existence, 
 and no longer remembered. Those, however, who have had 
 much intercourse with the aborigines of the country, inform 
 us that a tradition exists of an immense quadruped * * the 
 
MONSTERS OF A BURIED WORLD. 155 
 
 bison's grandfather" which, many moons ago, thundered 
 across the plains, and sent terror to the heart of the savage. 
 The Great Man, they say, slew them, because they were de- 
 stroying the Indians' game. That these creatures existed 
 down to the period of Indian occupation is evinced also, by 
 the discovery of arrow-heads buried in the same peats with 
 these bones, or in peats at greater depths even than some 
 which conceal the bones. 
 
 Such relics have been discovered also, in the Old World, 
 and former generations have been strongly inclined to attrib- 
 ute them to a race of giants now extinct. An intelligent in- 
 spection of these bones, however, shows that they never be- 
 longed to human giants, and can not, therefore, be the re- 
 mains or testimonials of the "giants" of antediluvian times. 
 Modern science has shown that they belonged to elephant-like 
 creatures, of two different genera. One of these was the true 
 Elephant, and the other is known as Mastodon. The Masto- 
 don has not been seen during historic times ; but we conclude 
 from the relics remaining, that it was very similar to the 
 Elephant, and differed chiefly in the structure of the grinding 
 teeth. The molars of the Elephant are enormously large, and 
 only one is in use in each jaw on each side, at one time. It 
 may be regarded, however, as a compound tooth, consisting 
 of ten or twenty simple flat teeth standing closely, and firmly 
 compacted together by means of a substance called cement. 
 The molar of the Mastodon has more the appearance of an 
 ordinary tooth, with three, four, or five transverse promi- 
 nences, rising like steep and furrowed ranges of mountains. It 
 is smaller than the elephant molar ; and three or four were in 
 use at once on each side of each jaw. 
 
 Commonly, as already indicated, the bones of the extinct 
 Elephant and Mastodon have been discovered in peat deposits. 
 Such deposits are explained in Talk VIII, and rest upon the 
 top of the Drift, and are more recent than the Drift. But in 
 Europe bones of the Elephant have sometimes been met with 
 in the modified Drift. They also occur in many caverns which 
 are believed to have been occupied by wild beasts in the 
 
156 WALKS AND TALKS. 
 
 Drift epoch. We may conclude, therefore, that the Elephant 
 came down from the Tertiary Age. Indeed, we shall see 
 from the facts to be stated in the next Talk, that both Ele- 
 phant and Mastodon began to exist before the Quaternary Age. 
 Some very remarkable facts have come to light from 
 northern Siberia. That inhospitable region was once a home 
 for tropic loving Elephants. More than a hundred years ago, 
 not only their ivory, but their carcasses, were known to exist 
 in Siberia imbedded in solid ice. The first discovery was on 
 the borders of the Aleseia River, w r hich flows into the Arctic 
 Ocean beyond the Indigirka. The body was still standing 
 erect, and was almost perfect. The skin remained in place, 
 and the hair and fur were still attached in spots. In 1772, 
 the body of a perfect two-toed rhinoceros covered with hair, 
 was found preserved in frozen gravel near the Vilhoui or 
 Wiljui, a tributary of the Lena, in latitude 64. The head 
 and feet of this animal also related to tropical species are 
 preserved in St. Petersburg. The most celebrated discovery 
 was made in 1799. A Tungusian fisherman named Schuma- 
 choff was exploring along the coast of the frozen ocean for 
 ivory. Near the mouth of the Lena he noticed, in a huge 
 block of clear glacier ice, a dark, strange object deeply im- 
 bedded. His half savage curiosity was not strong enough to 
 lead him to undertake the work of exploration. In 1801 the 
 melting of the ice had exposed a portion of the carcass. It 
 was a beast like those whose ivory lay strewn along those 
 frozen shores. In 1804, the Tungusian was able to remove 
 the tusks. They weighed three hundred pounds, and he dis- 
 posed of them for fifty rubles, to an ivory merchant. In 
 1806, Mr. Adams, who was collecting for the imperial museum 
 at St. Petersburg, found the carcass still on the shore, but 
 greatly mutilated. It appeared that the Yakutski had actu- 
 ally regaled their dogs upon the flesh ; and bears, wolves, wol- 
 verines, and foxes had gladly feasted upon it ! Fresh meat 
 already laid away in ice before that garden was planted in 
 Eden ! Thus this priceless relic of a prehistoric world was 
 allowed to waste away. But it was not completely lost to 
 
MONSTERS OF A BURIED WORLD. 157 
 
 science ; for except one fore-leg, the skeleton remained perfect. 
 A large part of the skin had also escaped destruction, together 
 with one of the ears, which still retained its characteristic tuft 
 of hairs. The skin was of a dark tint and was covered ^ith 
 reddish wool an inch in length, interspersed with reddish- 
 brown hairs four inches long, and sparser black bristles twelve 
 to sixteen inches long. Every thing of value was now col- 
 lected, including more than thirty pounds of fur ; the tusks 
 were repurchased, and the whole was transported to St. Peters- 
 burg, where the mounted specimen at present stands, in the 
 Imperial Museum. This individual was nine feet high and 
 sixteen feet long, exclusive of the tusks. 
 
 Other discoveries have been made more recently. In 1843, 
 a mammoth was found by Middendorf in so perfect a state 
 that the bulb of the eye is still preserved in the museum at 
 Moscow. In 1858, a mammoth was discovered in the delta 
 of the Lena, twenty-three miles from Sagastyr. The head 
 and tusks had already been removed by a Russian merchant. 
 The Yakuts soon after the discovery took a leg, several ribs 
 for making spoons, parts of the skin for straps, and fat for 
 painting their sledges. The body was reported in 1884 as 
 lying on its side in the lower part of a crag of alluvial de- 
 posits thirty feet high. Dr. Bunge, who undertook to exca- 
 vate on the spot, found the material a frozen mass of snow 
 "as hard as sugar." Still another mammoth was discovered 
 in 1878 on the Moloda River, a tributary of the Lena, which 
 it joins on the left thirty miles above Siktyakh. We shall 
 have to inquire, hereafter, what was the nature of the catas- 
 trophe which buried these huge quadrupeds in their common 
 tomb of ice. 
 
 The same Mammoth dwelt in Alaska. His tusks are ex- 
 tensively sought and sold for ivory. This utilization of the 
 ivory products of an age in which civilization had not yet ap- 
 peared, to learn the value of the product, recalls our reflec- 
 tion on the fossilization of sunlight for a more auspicious 
 period. 
 
 The great original skeleton standing in the Museum at 
 
158 WALKS AND TALKS. 
 
 St. Petersburg was duplicated at Stuttgart under the direc- 
 tion of Dr. Fraas, from various bones collected from different 
 parts of Europe. Dr. Fraas, from samples of skin and hair 
 still existing, ventured to give the extinct Mammoth a com- 
 plete restoration. Professor Ward, the great museum-builder 
 of America, saw this monster of Mammoths standing in the 
 Museum at Stuttgart and purchased it. Transporting it to 
 Rochester, he reared a duplicate, which stood for months in the 
 Ward Museum, where I had the opportunity of subjecting the 
 creature to a careful study. Let us go back and repeat the visit. 
 
 " As we enter the door of the building which has been 
 erected for the accommodation of this antediluvian, a dark 
 mountain of flesh rises before us. We had gauged our ap- 
 prehension to the familiar bulk of the elephant, but here the 
 eye must be lifted to a higher altitude; the whole thought 
 must swell to take in the idea of the towering form which 
 looms above us and frowns darkly and severely down upon us. 
 The monster's brow rises like some old granite dome, weather- 
 beaten and darkened by the lapse of geologic ages. Two 
 winding streams of ivory descend like glaciers from the base 
 of the dome, while the corrugated and beetling proboscis 
 swells between them like the embattled crest which divides 
 two Alpine glacier- torrents. Behind expands and uprises the 
 mountain mass of which these are the accessories. Serene and 
 motionless as Mont Blanc this majestic form stands awaiting 
 our wonder and adoration. No astonishment disconcerts it ; 
 no exclamations stir a feature. 
 
 Unlike the dumb mountain, however, this form seems in 
 a mood of contemplation. All this dark and towering mass 
 is conscious. There are eyes which open on us and take cog- 
 nizance of our movements ; there are ears which take in the 
 sounds of our voice. This creature contemplates us; he 
 throws a spell over us ; he has us in his power. 
 
 The mammoth ! aye the mammoth of mammoths ! With 
 long breath, after this suspense of amazement, we extricate 
 ourselves from his spell, and meet his overpowering stare 
 with the force of intelligent will. He is but a beast let us 
 
MONSTERS OF A BURIED WORLD. 159 
 
 analyze the sources of his power over us. He stands sixteen 
 feet in height. His extreme length is twenty-six feet, and 
 the distance between the tips of his tusks is fourteen feet. 
 His body is thirty feet in circumference close to the skin. 
 The sole of his foot is three feet in diameter. His tusks are 
 fourteen feet long and one foot in diameter at base. Between 
 his short, post-like fore-legs a man can stand upright with 
 his hat on, without touching the animal's body. The whole 
 exterior is clothed with dark shaggy hair, quite unlike the 
 modern elephants, and under the throat it attains a length of 
 twelve to fifteen inches." 
 
 Here the old Siberian Mammoth enjoys his bodily resur- 
 rection. Dr. Fraas was the angel of the resurrection, and 
 has made him as nearly as possible like his ancient self. Dr. 
 Fraas is an eminent anatomist and geologist, and we trust his 
 judgment and his veracity. 
 
 Europe, Asia, and America had their Mammoth and Mas- 
 todon in the Quaternary Age ; and their bones and carcasses 
 still lie preserved in Drift deposits to testify to their existence. 
 South America, however, had its MegatJwrium, its Mylodon, 
 its Scelidotfierium, and other strange giants of the order known 
 as Edentates. These have been found imbedded in the " Pam- 
 pean Formation," which extends from Brazil nearly to the 
 Straits of Magellan. It is mostly a level and sparsely wooded 
 plain, covered by a rich soil underlaid by gravel and sand. 
 Numerous marine remains indicate that it was covered by the 
 sea during a period geologically recent. In this formation 
 have been found the ponderous bones of a colossal ground- 
 sloth, now known as Megatherium. The first relics were dis- 
 covered in 1789, near the city of Buenos Ayres. A nearly 
 complete skeleton was sent to Madrid, where it still stands, the 
 chief scientific attraction of the Spanish capital. Through 
 various other discoveries, entire skeletons have been recon- 
 structed, the most perfect of which stands in the British Mu- 
 seum. Plaster copies of this have been made under the di- 
 rection of Professor Ward, and the Megatherium is now a 
 familiar sight in American museums. A restoration complete 
 
160 WALKS AND TALKS. 
 
 was attempted by Waterhouse Hawkins, and cuts of this are 
 now found in most of the text-books. 
 
 This was one of the most anomalous creatures of the strange 
 past. It was one of the last of the great " comprehensive types " 
 which appeared in the progress of the history of life, and of 
 which you will hear much, as we trace this history backward. 
 It was studied by the great Cuvier, among many others, and 
 he first revealed its true affinities. Some regarded it as tree- 
 inhabiting; some thought it subterranean; Owen decided that 
 it must have lived upon the ground. As represented by 
 Hawkins, it stands semi-erect, resting on its massive hinder- 
 extremities, with auxiliary support from a vast pillar-like tail, 
 with anterior extremities clasping the trunk of a tree and 
 relatively diminutive head and tapir-like snout turned up- 
 ward toward the foliage which probably served as its food. 
 
 The length of the skull is thirty-one inches ; its breadth, 
 eighteen. The brain-box is very small for the bulk of the 
 animal. The molar teeth have hollow fangs for continuous 
 growth, as in the sloth and many modern rodents. The 
 spinal column is 15J feet long. The circumference of the 
 skeleton at the eighth rib is ten feet. The scapula is a vast 
 expanse of bone two and a half feet long. The distal (farther) 
 end of the humerus is 13 inches wide, while that of the ele- 
 phant is only one-fourth as great. The pelvis is a mountain 
 of bone. It is far more massive than that of the elephant or 
 any known animal, living or extinct. Its extreme breadth is 
 upward of five feet that of the Asiatic elephant being six- 
 teen inches less. The socket for the head of the femur pre- 
 sents a surface of 44 square inches, which is 200 times the 
 same surface in the pigmy shrew-mouse. The thigh bone, in 
 the Mastodon and Elephant, appears weak and slender com- 
 pared with that of the Megatherium. It is two feet two inches 
 in circumference at the largest part. The hind legs look 
 more like columns for the support of a bridge than like or- 
 gans for locomotion. The circumference of the tail at its 
 largest part was six feet. 
 
 We have to imagine this gigantic framework clothed with 
 
MONSTERS OF A BURIED WORLD. 161 
 
 flesh and instinct with life. It towers before us a huge, un- 
 gainly beast, eighteen feet in length and eight feet high, hav- 
 ing a tapir-like head, an elephantine body, and hind feet and 
 tail which find no match in geologic or historic time. Such 
 super-mammoth haunches, nearly six feet across ; such singular, 
 half-hoofed, half-clawed extremities; so slow and awkward in 
 his movements ; so stupid in look he seems the lord of the 
 Pampas. His thick and callous hide is scantily clothed with 
 coarse, stiff hair. He seeks his food from the leaves of the 
 forest. Other leaf-eaters possess various provision for securing 
 their food. The elephant is furnished with an elongated pro- 
 boscis. The giraffe is uplifted on fore-legs of extraordinary 
 length, supplemented by a neck of length equally extraordi- 
 nary, and lips and tongue co-ordinated with other parts of his 
 outfit. The sloth ascends the tree and places himself in the 
 midst of the foliage on which he must subsist. Our Megath- 
 erium has none of the provisions of the elephant or giraffe, 
 and is too ponderous to be borne by the branches of a tree. 
 He raises himself in a semi-erect attitude, supported by that 
 tripod formed of tail and hind feet, and reaches with his fore- 
 limbs to the foliage and gathers it in. When the supply falls 
 short, he employs his powerful effodient feet to hurl the earth 
 from the roots of the tree, and bring it down by his colossal 
 strength. Then he stretches himself alongside of the prostrate 
 tree and gathers its foliage at his leisure. 
 
 These are samples of the relics of the Quaternary Age. 
 Those who become interested will find further information in 
 works on geology. In North America are found remains of 
 a pig-like creature, a gigantic beaver and some Edentates. 
 They are found imbedded in sand and fluviatile deposits, ac- 
 cumulated, like the elephant-bearing peats, after the Drift. 
 The boulder Drift is mostly destitute of organic remains. 
 Probably the severity of the temperature and the prevalence 
 of ice rendered animal life impossible. What the facts were, 
 it will be our business to ascertain ; and by and by we shall 
 be in a position to reconstruct the story of the times. 
 
 14 
 
162 WALKS AND TALKS. 
 
 2OCVIII. THE CElVtETTKRIKS OR THE 
 
 TERTIARY FOSSILS. 
 
 THE "Bad Lands" in the dialect of the trapper and In- 
 dian, are regions unfavorable to the pursuit of their occupa- 
 tions ; as the snow-covered slopes of the Alps are Monts mau- 
 dits (cursed mountains) in Savoy, and an unavailable ridge in 
 the Pyrenees is Monte maladetta to the Spaniard. The Bad 
 Lands of the United States are underlaid by Tertiary strata 
 which have been worn and wasted in innumerable fantastic 
 shapes, and excavated on so vast a scale as to expose to view 
 the relics of the creatures buried beneath the rubbish of hun- 
 dreds of thousands of years. In order of succession these 
 strata lie further than the Quaternary deposits from the com- 
 pleted surface. Still, there are extensive regions where noth- 
 ing more modern covers the wastes of the Bad Lands ; but 
 that is only because the work of geological building stood still 
 during an epoch. 
 
 Inspect the rocks of some Tertiary district; we are pretty 
 sure to find them horizontal or nearly so. Along the Atlantic 
 and Gulf coasts, they slope gently toward the sea. In some 
 parts of the Pacific coast, the Tertiary strata have been tilted 
 to high angles and subjected to metamorphic action. In the 
 interior of the continent they generally lie in positions nearly 
 horizontal. Tertiary strata which slope down to the sea and 
 under it or once had such a slope are of marine origin, 
 and contain relics of marine populations. In the interior, we 
 find the fossil remains mostly those of fresh water and the 
 land. In some of the deepest Tertiary of the interior, the 
 aquatic forms are brackish-water species ; and those from the 
 lowest beds are sometimes salt water species. These facts are 
 important in setting in order the history of Tertiary times. 
 
 Let us visit one of these desert spaces of the continent. 
 We leave the valley of the upper Missouri and travel over- 
 laud across plains parched by drouth and clothed only with 
 scattered sage brush. The buffalo is not found grazing here; 
 
THE CEMETERIES OP THE BAD LANDS. 163 
 
 birds and insects avoid the herbless waste. Our mules toil on 
 in the withering heat of summer, and reach with weariness 
 the border of a shrunken stream on which to encamp. With 
 patient progress we arrive at a region which shows symptoms 
 of a change of scene. Ahead, appears a less monotonous land- 
 scape. Some breaks in the surface are revealed. There, in 
 the distance, are forms which remind us of architectural struc- 
 tures. We seem to see gables and towers. There rise the 
 vertical lines of columns and steeples and pinnacles. Is this a 
 city in the desert Persepolis on American soil? 
 
 We press on. The illusion dissolves. Before us stretches 
 a wide excavation, down into the formations underneath. 
 Where are the materials removed from this emptied basin? 
 What power plowed up the strata and carted away the debris? 
 We come to the brink of the basin a vast rock basin cut 
 through beds of horizontal shales and soft limestones. The 
 sloping walls have been worn for a thousand centuries by the 
 rills formed from the winter rains. The fluted columns have 
 been grooved by water. The salient abutments have been 
 chiseled by the storm. 
 
 The rock-layers are visible all around the depression. We 
 descend to the floor and trace their continuity from side to 
 side. Each layer was once a sea-bottom. But, behold the 
 relics of a former population scattered over this floor. Here 
 are the skulls of sheep-like creatures which are also pig-like ; 
 the carapaces of turtles unlike any turtles living; the shin- 
 bones of rhinoceroses which no longer roam in the jungle. 
 We turn our eyes again to the rocky layers, and lo! like 
 shelves of a vast cabinet, they hold the specimens which illus- 
 trate a fauna passed away a classified cabinet, where each 
 shelf is stored with the relics of its epoch, and the lower 
 shelves are filled with the souvenirs of the older time. 
 
 What a place is this for reflection ! All about us are the 
 bones of extinct populations. They lie beneath us; they are 
 stored around us, and their empty sockets gaze out on us with 
 startled astonishment ; they rise above our heads. We are 
 sunken in the center of an ancient cemetery; we have burst 
 
164 WALKS AND TALKS. 
 
 into the midst of a sleeping, dreamy Golgotha, descended 
 from the vast dead past. How old are these graves? Through 
 how many winter storms have these silent skeletons slept here ? 
 How they rise, story above story. These bottom tiers lay 
 down to their long repose while the great lake flapped its 
 waves above. Its fishes swam over cemeteries. Other 
 mute remains came in, layer by layer, to the house of silence, 
 and the hand of Nature carefully envaulted them. The re- 
 ceptacle was filled; the lake had vanished; the continent 
 was here. 
 
 Life once thrilled through all these torpid frames. These 
 were conscious creatures. These were joyous creatures walk- 
 ing on the green earth. These were beings which inhaled 
 the vital air, and basked in the life-giving sunlight, and en- 
 joyed each other's society. They fed on the productions of 
 the forest and the glade. They wandered over a land which 
 was to be Dakota and Nebraska. They slaked their thirst at 
 the border of the wide lake; they cooled themselves in its 
 waters, and sometimes sported with its waves. Death came to 
 them, as to their thousands of predecessors as it comes to us. 
 They were mired in a slough ; they were hunted in a jungle ; 
 they lay down in the shade of a friendly tree ; some force of 
 nature bore them to their burial. The lake was their tomb, 
 and the lake preserved its trust. It was a later vicissitude 
 which opened the cemetery and exposed these testimonies of a 
 vanished age to the curious and irreverent scrutiny of science. 
 
 The formation in which these creatures are entombed 
 stretches from eastern Nebraska to Laramie, and from the 
 Cheyenne River, Dakota, into north-western Kansas. It is 
 called Neocene or Upper Tertiary. Other smaller areas of 
 the same exist in Colorado, Wyoming, Montana, and Nevada. 
 A very large area exists also in Oregon and Washington Ter- 
 ritory. Upper Tertiary strata also border the Gulf of Mexico, 
 from Mobile to the Rio Grande, stretching inland a hundred 
 miles, and up the valley of the Mississippi to Cairo. Near 
 the gulf shore, however, and along the Delta of the Missis- 
 sippi the Neocene is concealed by alluvial deposits. Neocene 
 
THE CEMETERIES OF THE BAD LANDS. 165 
 
 Tertiary stretches along the Atlantic coast also, from Montauk 
 Point to the southern part of Florida from Charleston south- 
 ward, however, overlaid next the shore by a narrow belt of 
 alluvial or recent deposits. There are few remains of land 
 animals in the marine Tertiary ; but shells and corals are 
 plentiful. A majority of them belong to the same species as 
 are now living in the nearest parts of the Atlantic. Near 
 Charleston, however, have been found the remains of a horse 
 more resembling the domestic horse than those in the Bad 
 Lands. Indeed, the Carolina horse was extremely like the 
 species long afterward brought to America from Europe. As 
 this species is not known in the Neocene of Europe, the indi- 
 cations are that it lived in America before it did in Europe. 
 That is, the late Tertiary horse originated in America ; after- 
 ward found its way to Europe and Asia, and finally was 
 brought back to the new world by immigrants in the sixteenth 
 century. Almost the same story has to be told of the camel. 
 But there are older Tertiary deposits called Eocene, which 
 means the " dawn of the recent," because the marine shells 
 found in them contain a few recent species, and only a few, 
 while the shells of all older formations are specifically distinct 
 from any now living. The Eocene strata are seen passing 
 under the Neocene all along the Atlantic and Gulf border, 
 and up the delta of the Mississippi. When these strata were 
 deposited, the Atlantic and gulf extended to the inland limit 
 of the Eocene. The valley of the Mississippi as far. as Cairo 
 was under the Gulf a bay setting northward to Cairo from 
 about the latitude of Montgomery, Alabama. In this sea 
 sported the great Zeuglodon a vertebrate of whale-like nature, 
 but serpent-like form, which on the first discovery of its re- 
 mains, was supposed to be a real sea-serpent. Its length was 
 sixty to eighty feet. A skeleton dug up in Clarke County, 
 Alabama, by Dr. Koch, was named Hydrarchos king of the 
 hydras and was formerly exhibited in Barnum's Museum, 
 New York afterward sent to London, where Professor 
 Richard Owen determined its true nature. Another specimen 
 was on exhibition some years ago, in Wood's Museum, Chi- 
 
166 WALKS AND TALKS. 
 
 cago. The vertebrae of this curious whale are found strewn 
 over the corn and cotton fields of Southern Alabama. I have 
 seen them used for andirons in the rude fireplaces of the 
 country, and set for steps of a stile over the front fence of 
 the door yard. 
 
 The region underlaid by the Eocene abounds in shells and 
 corals and fish-teeth washed out by the weather. The strata 
 are mostly friable, and some almost incoherent. The rivers 
 and creeks have excavated deep channels, and thus caused 
 many fine exposures. The most celebrated river bluffs in the 
 Alabama and Mississippi Eocene are at Claiborne, St. Stephens, 
 and Vicksburg. All these localities abound in fossils, but 
 especially the first and last named ; and the fossils exist in a 
 perfect state of preservation. At St. Stephens we find the 
 "White Limestone" which incloses the remains of Zeuglodon. 
 Eocene fossils are found in great abundance also, along all 
 the creeks and ravines, and by the road sides. I congratulate 
 the reader who resides in those regions, since his opportunities 
 for field study are almost un equaled. 
 
 For many, the remains inclosed in the fresh-water Eocene 
 of our western territories possess still greater interest; for 
 they are the bones and teeth of strange and often gigantic 
 quadrupeds which dwelt on the land. In the south-western 
 part of Wyoming, and extending south to the Uinta mount- 
 ains, is a great expanse of such strata. On the south of the 
 Uinta mountains is another, extending south-eastward into 
 Colorado, and south and south-westward into Central Utah. 
 Another vast Eocene region stretches from southern Colorado 
 into New Mexico. It is chiefly from the Eocene of Wyom- 
 ing that Professor Marsh obtained the mammalian bones 
 which, during many years back, he has described for the 
 astonishment of the world. Some very unique material, how- 
 ever, was procured in Oregon. The equal work performed 
 by Professor Cope, has also been based partly on specimens 
 from Wyoming, but more largely on material from New 
 Mexico and Texas. These wide, western regions pastured 
 herds of herbivores in the early Tertiary time, as they have 
 
LESSON FROM A LUMP OF CHALK. 167 
 
 continued to do down to the invasion of the locomotive and 
 the transformations of civilization. ::;-v-.; 
 
 I can not undertake to convey to your comprehension, in 
 a few lines, any adequate conception of the aspects and char- 
 acters of these long extinct beings. If we speak only of 
 mammals, we can say that they generally differed widely 
 often grotesquely from any forms now living. It was then 
 near the beginning of mammalian development on the earth. 
 Still those creatures presented unmistakable resemblances to 
 modern mammals, in all fundamental respects. If there were 
 no elephants, there were the Brontotherium and Dinoceras and 
 Tinoceras, and especially in the Old World, the Dinotherium, 
 which seemed like uncouth and undeveloped pachyderms trying 
 to become proboscidians. But the Brontotherium had no tusks, 
 no trunk, no elephantine molars. The "comprehensive" char- 
 acter of these and other early mammals was the most inter- 
 esting fact ; but I reserve more particular mention for a later 
 opportunity. 
 
 . L/ESSON KRONl A IvUMP OK 
 MESOZOIC ROCKS AND FOSSILS. 
 
 THIS white lump, soft enough to be cut with a knife, effer- 
 vesces very briskly when any strong acid is applied to it. 
 Even strong vinegar causes the formation of a multitude of 
 small bubbles. Effervescence is caused by the escape of some 
 gas. Almost always, the gas is carbonic acid, or as we now 
 say, carbon dioxide. Chalk is a compound of this and cal- 
 cium. The latter is familiar in the form of lime. Carbonic 
 acid is feeble, and when the strong acid is applied to the 
 chalk, it drives off the carbonic acid, and takes possession of 
 the calcium for itself, forming a different compound. The 
 carbonic acid when freed from combination, resumes its 
 gaseous form. It therefore swells up, and mixed with the 
 water of the strong acid, produces the bubbles which consti- 
 tute effervescence. Chalk, however, has essentially the same 
 constitution as limestone and marls. 
 
168 WALKS AND TALKS. 
 
 If we pulverize some of this chalk and examine the parti- 
 cles with a microscope, we discover that the greater part con- 
 sists of minute shells or shell-fragments. Indeed, here is 
 Globigerina again ! We found Globigerina in our "Walk Un- 
 der the Sea" (Talk IX.) Billions upon billions of these 
 minute shells accumulated together, have formed that white 
 ooze which overspreads so large a part of the deep sea-bottom. 
 If some of that ooze should be compressed and dried, it would 
 be exceedingly like chalk. There is little doubt that the real 
 chalk so abundant in Europe, was originally a white ooze in 
 the bottom of the ocean the deep parts of the ocean when 
 much of Great Britain and the continent was buried in abyssal 
 waters. What we found in the depths of the Atlantic must 
 be a modern picture of the condition of the ancient ocean 
 which covered Europe some millions of years ago. The bot- 
 tom of the Atlantic was then the bottom of the Atlantic. Its 
 present [condition has been perpetuated from the Cretaceous 
 Age ; and many of the minute forms accumulating there to- 
 day are generically identical with the forms which lived when 
 the chalk was a sea-bottom. 
 
 A few years ago, when these things were first ascertained, 
 and the first announcement was made that the fossil forms of 
 the chalk were still living in the Atlantic a triumphant outcry 
 was made through the newspapers by the ignorant enemies of 
 geological science. It has since Cuvier, always been a funda- 
 mental doctrine in geology, that the earth's surface has been 
 occupied by a succession of populations showing progressive 
 advancement toward the modern aspects of the world. But 
 "here," they affirmed, "we find no change since the chalk. 
 The foundation of geology is disrupted. The so-called science 
 is a baseless mass of ' theories ! ' There is no sound evidence 
 of the great age of the world. The ' days ' of Genesis were 
 twenty-four hours long. Hurrah ! " 
 
 The life of geology was scarcely conscious of a ripple. The 
 old principles rest firmly. The facts cited, instead of proving 
 destructive, confirm another doctrine even more dreadful than 
 that of successive faunas and great antiquity the doctrine 
 
LESSON FROM A LUMP OF CHALK. 169 
 
 of correlation of organic structure with environment. Faunas 
 change as the physical surroundings change ; but if the physi- 
 cal surroundings remain changeless, the faunas remain change- 
 less. Down in the deep sea, with a constant temperature of 
 freezing water; with perpetual absence of the stimulus of 
 light ; without motion ; without change of chemical condi- 
 tions with almost absolute changelessness for ages, why should 
 organisms change ? They are now suited to the environment ; 
 they could not change without becoming unsuited to the en- 
 vironment. The forms from the Age of Chalk have survived 
 because a deeper principle than that of succession of faunas 
 has been dominant. It is the principle of correlation of en- 
 vironment and organism. The animal must be adapted to its 
 surroundings. Nearly all the populations which have lived 
 dwelt on land or in comparatively shallow water, where 
 environment was undergoing progressive change ; hence suc- 
 cession of faunas. A few deep sea species have dwelt where 
 change of physical conditions is almost unknown; hence a 
 nearly changeless fauna. Thus a piece of chalk reveals a deep 
 and important principle. 
 
 The position of the chalk-beds in the series of geological 
 formations is nearly at the top of the Cretaceous System. The 
 System, besides the beds of chalk, contains strata of sand and 
 clay. One variety of sand is green, and in New Jersey, oppo- 
 site Philadelphia, it is dug extensively for fertilizing soils, 
 since, as you will infer, it is not a purely silicious sand, but 
 contains a large percentage of potash. The Cretaceous strata 
 extend along the belt parallel to the Atlantic and Gulf coasts, 
 into Mexico ; but from Maryland to Georgia, the Atlantic belt 
 is mostly covered and concealed by the Tertiary beds. From 
 middle Georgia, a broad belt extends into eastern Mississippi, 
 and thence north to the Ohio river near Cairo. West of this, 
 the Cretaceous strata are concealed by Tertiary and Mississippi 
 alluvium, as far as Little Rock. Near here an exposed belt 
 begins which widens extensively toward the southwest, through 
 Texas. Remember that the place of the Tertiary strata is 
 
 always between the Cretaceous and the ocean. The Cretaceous 
 
 15 
 
170 WALKS AND TALKS. 
 
 strata go down under the Tertiary, and probably under the 
 Gulf and a portion of the Atlantic. 
 
 There is no proper chalk in the Cretaceous beds of the 
 United States. In the Gulf States, however, is a buffish soft 
 limestone, called the " Rotten Limestone," slightly resembling 
 chalk. As it disintegrates and mingles with vegetable matter, 
 it forms a very rich, black soil. This underlies the very best 
 cotton lands of Georgia, Alabama, and eastern Mississippi. 
 The lower part of the System contains beds of sand interstrati- 
 fied with clays and shales. These convey rain water down and 
 southward from their belts of outcrop. So when holes are 
 bored from the surface down to these water-bearing sands, sup- 
 plies of water are obtained. Hence it is, that at Selma, 
 Cahaba, and throughout the Cretaceous region, Artesian wells 
 abound. 
 
 The Cretaceous rocks of the Gulf States are rich in fossil 
 remains ; often, in riding along the highway, one's eye is ar- 
 rested by some weathered knoll close by the roadside, thickly 
 overstrewn with teeth and vertebrae of sharks and rays of 
 various extinct species as if one were traveling over a sea- 
 bottom. Here also, are multitudes of small and curious oys- 
 ter shells, and many other sorts of shells. Where the rivers 
 and creeks have cut through the Cretaceous strata we find 
 excellent sections. One of the most famous of these is at 
 Prairie Bluff, on the Black Warrior river, in Greene county, 
 Alabama. Here the "rotten limestone" is at the top; then 
 come beds of sand formed evidently, not far from the ancient 
 shore, which lay on the north, just beyond Selma and a little 
 south of Tuscaloosa. These sands contain bits of wood, and, 
 in one instance, I remember seeing the trunk of a tree project- 
 ing several feet from the cliff toward the river. The wood 
 contained a good amount of iron pyrites, but some of it could 
 still be cut with a knife. Here is one layer of cemented sand 
 completely packed with small oysters. How many of these sa- 
 vory bivalves must have gone to waste in those middle geolo- 
 gic ages ! But I suppose they served as food for other ani- 
 mals whose appetites were as worthy of regard as man's. In 
 
LESSONS FROM A LUMP OF CHALK. 171 
 
 other strata I have picked up oyster shells seven inches in 
 diameter, and nearly round. Single valves, I think weigh 
 sometimes two or. three pounds. One might have broiled oys- 
 ter steaks if he had lived in those days. The Cretaceous 
 strata seem to have been a literal oyster cemetery. 
 
 But who, after all, would prefer to have lived in those 
 times? Even had human society been supplied, the world 
 was really not prepared for man. We do not find any bones 
 of horses or oxen, or any of our domestic and useful animals. 
 Nor do we find remains of any of our fruit-bearing trees or 
 berries of any kind. I think we should have lost more than 
 all the gain far more. Instead of relics of domestic animals, 
 we discover teeth and vertebrae of sharks of different tribes 
 some with tapering, lance-like teeth, some very long and slen- 
 der, and some flat and lying like paving stones on the bottom 
 of the mouth. Here too are the vertebrae of a long and 
 snake-like reptile known as Mosasaur. It was probably a 
 genuine "sea-serpent." The relics of these ancient popula- 
 tions are now plowed up in the cotton fields. In the region 
 south of Selma I have seen the precious relics of curious and 
 extraordinary shells, which we call Rudwtes, carted together 
 and burned for lime to whitewash log-cabins. 
 
 From Texas, the great Cretaceous belt can be traced 
 northward to Kansas, Nebraska, Minnesota, Dakota, and 
 British America. It extends, indeed, along the east flanks of 
 the Rocky Mountains, apparently to the Arctic Ocean. 
 These are interesting facts. They demonstrate that there 
 was a time when an ocean stretched from the Gulf of Mexico, 
 through the middle of our continent, to the Arctic. These 
 Cretaceous strata contain neither chalk nor " rotten limestone." 
 They were not formed in a deep sea. There are vast forma- 
 tions of clay and shale, and at the bottom is a thick sand- 
 stone, often conglomeritic, which can be traced from Kansas 
 to the Wahsatch Mountains but not in one continuous sheet. 
 All these Cretaceous strata being formed of fragments coarse 
 or fine, are called fragmentaL Evidently they were laid down 
 in waters mostly shallow, and to a great extent, near the 
 
172 WALKS AND TALKS. 
 
 shore. The western Cretaceous beds contain many strata of 
 coal ; and this is other evidence of water so shallow as to be^ 
 come frequently dry land. The fine coals of Wyoming and 
 of the Cascade Mountains in Washington Territory are 
 Cretaceous. 
 
 These strata are the burial places of gigantic reptiles 
 dwellers in the sea and dwellers on the land. Some of their 
 forms were amazingly elongate. Some attained a length of 
 fifty to one hundred feet. I must give you the name of one 
 of these Ca-mar"-o-sau'-rus. The bones were found by Cope in 
 Colorado. He says: "One of the vertebrae of the neck was 
 twenty inches long and twelve inches in transverse diameter. 
 The shoulder-blade was 5^ feet long, and the thigh-bone five. 
 The total length of the reptile must have been 72 feet." Am- 
 phi-cwl'-i-as had a thigh bone six feet hi length and a body 
 over a hundred feet long. Marsh has discovered, also, enor- 
 mous reptilian bones in Kansas, and some of them are remark- 
 ably peculiar. I can not enter into details at this place ; but 
 by and by we will take a general view of the wonderful em- 
 pire of reptiles. 
 
 Another system, the Jurassic, underlies the Cretaceous, 
 and we find its shales and limestones widely distributed in the 
 far west. It was a closed record before the activities of Cre- 
 taceous life began. It incloses the memorials of huge and 
 numerous Dinosaurian reptiles, and it was in fact from these 
 repositories that Marsh derived the material to give interest and 
 romance to his reptilian memoirs. Lower still lie the sand- 
 stones of the Triassic, and these are the solid tombs of the 
 hoar forerunners of the swarming dynasty of reptiles. The 
 Triassic is represented in the eastern states by the red and 
 brown sandstones of North Carolina, northern New Jersey 
 and the valley of the Connecticut. From the quarries along 
 the Connecticut are obtained the materials for the fine brown- 
 stone fronts of New York. But these stones are rich in in- 
 terest for the geologist as well as the builder. They contain 
 the records of a daily life which opens vistas into a wonder- 
 ful past where Nature is seen in one of her stages of transi- 
 
LONE BURIALS IN THE COAL LANDS. 173 
 
 tion from type to type. We glimpse the stalking forms of 
 bird-like reptiles as we uncover the tracks which they made 
 in the world's middle ages; but we drop the curtain to raise 
 it again in another scene. 
 
 XXX. IVONK BURIALS IN THE COAL 
 
 COAL-MEASURE FOSSILS. 
 
 STILL deeper in the series of strata which compose the up- 
 per portion of the earth's crust, we come to the coal-beds 
 which were described in Talk XXVI. We wish now to con- 
 sider very briefly the organic forms which the coal strata in- 
 close. We refer here to coal strata of "Carboniferous Age," 
 such as found in the United States east of the Kocky Mount- 
 ains excepting the Richmond and Deep River fields in 
 Virginia and North Carolina. You will remember that we de- 
 tected evidences of the vegetable origin of the coal. We con- 
 clude that it was formed from trees and herbaceous plants 
 which had grown in the places where the coal accumulated. 
 Generally, that ancient vegetation has become broken, com- 
 minuted and decayed like the forest leaves gathered in a 
 pile and left to the influence of the weather during one or two 
 seasons. Still, many distinct traces of the coal-plants lie bed- 
 ded in the formless rubbish of the ancient forest. Pressed 
 upon the black surfaces of the shales are innumerable tracer- 
 ies of fern fronds, with all the sharpness of pinnations and 
 bipinnations, their serrations and acuminations, as neatly 
 preserved as if gathered last week from the forest and pressed 
 by careful hands for the herbarium. It is an interesting 
 sight ; it fills our minds with reflections. Down four hundred 
 feet in the solid earth, reposing in darkness and silence through 
 all the ages of our human history, have these elegant pictures 
 been lying forms out of a vanished world types of times 
 which passed while terrestrial life was still in its infancy, and 
 vegetation had not yet learned to blossom in the hues of the 
 violet and the rose. 
 
174 WALKS AND TALKS. 
 
 Here too, are imbedded stems covered all over with seal- 
 like impressions arranged in diagonally winding series. Such 
 a tree was Lep-i-do-deri-dron, or "scaly tree," which grew to a 
 height of a hundred feet, with a stem twelve feet in circum- 
 ference. Some of the smaller samples of these stems 
 or branches bear a remote resemblance to the exterior of a 
 snake ; and I have had specimens brought as petrified snakes ! 
 Did you ever observe that the more ignorant people are, the 
 more confident they are of the correctness of their interpreta- 
 tions of nature? Some men entertain no thought whatever that 
 these fossil sticks are any thing different from what their fancy 
 suggests. They do not observe that the specimen is broken at 
 both ends ; that there is no taper toward each extremity, as 
 in a snake, and that the forms mistaken for scales are not 
 closely in contact as in snakes, and are indented by a distinct 
 figure, rather than elevated and flat, with a delicate raised 
 line along the middle, as in most snake "scutes," as we call 
 them. 
 
 We find also another kind of stems, with similar seal-like 
 impressions, but arranged in lines lengthwise of the stem 
 and more remote from each other. This kind of tree is Sig- 
 il-la'-ri-a or "seal-tree." Quite often we find the stump and 
 roots of these trees deeper down in the sandy clay in which 
 the tree originally grew. These are marked by scattered, 
 deep impressions, as if made by a sharp stick. Before these 
 were known to be the roots of Sigillaria, they were named 
 Stig-ma'-ri-a or "mark-tree." 
 
 These trees were not like any species now living. They 
 produced no flowers or fruits which could be compared with 
 those of modern vegetation. Yet we must admit that they 
 possessed resemblances to several, different kinds of modern 
 vegetation. When we get a fossil organism of this kind, we 
 say it is "comprehensive." Thus, Lepidodendron had some 
 structures which affiliated it with our modern "ground pine" 
 (Lycopodium) . In another particular it was like the Cycads 
 of tropical regions. In some characters of the wood it was a 
 fir or pine, while in others it was a fern. The "scars" re- 
 
LONE BURIALS IN THE COAL LANDS. 175 
 
 ferred to were left by the fallen fronds or leaves, and in these 
 it also resembled ferns. We base these inferences on the 
 study of specimens imbedded in the strata associated with the 
 coal. All comprehensive types are primitive and low in rank. 
 The low rank of these plants is evinced also by the absence 
 of flowers and fruit. 
 
 But we find here, also, the relics of once animated forms. 
 As the coal was produced on the land; as the vegetation 
 grew on the land, the animal remains would be those of the 
 land. They would be air-breathers. So here they are Snails 
 air-breathing mollusks. Every one has noticed the snail 
 crawling about with his house on his back. He lives in damp 
 retired places, and feeds on the leaves of herbs. The situation 
 must have been sufficiently retired ten million years ago in a 
 a forest where the woodman's axe never resounded, and foot- 
 step neither of man nor beast was ever heard. But distant 
 as was the age, snail natures were very similar to snail 
 natures in the nineteenth century. Even then, they congre- 
 gated on the peaty soil in the damp situations about old 
 stumps. They held there their social meetings, and some- 
 times they found a more secure and congenial retreat in the 
 interior of a stump hollowed by age and decay. In such 
 situations they have been found especially in the enormously 
 developed coal measures of Nova Scotia. We find two types 
 of land-snails in the Coal Measures ; one is like our modern 
 genus Helix, and the other resembles Pupa. 
 
 I just now intimated that these humble air-breathers were 
 not disturbed in their retreats by man or beast. This is 
 simply a conclusion from the fossil remains. These are the 
 most important records of the past. Since no bones of human 
 beings nor of any mammals have ever been found fossilized 
 in the Coal Measures, we feel justified in concluding that man 
 and mammals were not in existence while the coal beds accu- 
 mulated. We have got down to a geological horizon or level 
 which answers to a time when the higher organisms had not 
 appeared. So we see that they have not enjoyed an eternal 
 existence on the earth. But we do find bones of vertebrates 
 
176 WALKS AND TALKS. 
 
 back-bones, skulls, limbs, and teeth. It is doubtful whether 
 they belonged to vertebrates as high even as reptiles. You 
 remember that the beds of ancient reptiles were passed at 
 higher levels. The bones here seem to be those of Amphib- 
 ians and Fishes. Amphibians, perhaps you understand, are 
 reptile-shaped animals which breathe water when young and 
 air when adult. Frogs and toads are living Amphibians with- 
 out tail. Salamanders, tritons, axolotls, and fish-lizards are 
 Amphibians with tails. But fish-lizards retain their gills 
 throughout life. The gills are beautifully fringed, scarlet, ex- 
 ternal appendages, projecting from the neck on each side. 
 We call them amphibians because in their structure they so 
 much resemble salamanders. Moreover, the axolotl, while in 
 the elevated regions of Colorado it retains its gills permanently, 
 in less elevated regions, absorbs them and becomes a sala- 
 mander. So it happens that the permanence or absorption of 
 the gills is not a circumstance of very great importance. 
 
 This thought leads me to add that in the plan of all ver- 
 tebrates, provision is made for the development of both gills 
 and lungs ; but generally only one sort of respiratory organ 
 is actually developed ; and that depends on the life the animal 
 is to lead. Man himself has provision for gills in the early 
 embryonic stages of his being. The eggs of Amphibians are 
 deposited and hatched in water, and the young must, there- 
 fore, be fitted with gills. All vertebrates below Amphibians 
 have gills for a permanency ; all above, have lungs for a per- 
 manency. The Amphibian is on the dividing line. In the 
 lowest phase of its existence, it goes with fishes ; in the highest 
 phase, it goes with reptiles. Its life is double. But, on the 
 one hand, the separating line leaves the fish-lizard wholly on 
 the aquatic side ; and so, on the other it leaves the toad, in 
 some cases, wholly on the land side ; since toads sometimes 
 rear their young without finding their way to the water. 
 
 These amphibious border-land creatures possess very great 
 interest ; and so this type of creatures fossilized in the Coal 
 Measures, throws much light on the problem of life and 
 organization. They are border-land creatures here in an addi- 
 
LONE BURIALS IN THE COAL LANDS. 177 
 
 tional sense. Contiguous to them in earlier time, lived only 
 water-breathing fishes; next following them in time, were the 
 air breathing reptiles. Here you notice a certain succession 
 in geological history which is reproduced in the life-time of 
 the individual amphibian. Why this parallelism? What 
 causes it ? I shall try to answer these questions in due time. 
 For the present we only stick a pin. 
 
 Let us look a little more closely at some of these Coal 
 Measure Amphibians. At Lin ton, Ohio, and Morris, Illinois, 
 and at the Joggins in Nova Scotia, we find their blackened 
 bones in greatest abundance. There is one type in which the 
 animal was but a few inches long and had the shape and 
 aspect of a salamander that is, with a long tail and four 
 limbs. Another type was similar, but was covered with scales 
 or small bony plates. Still another had no limbs, or at most 
 only two, and the form was long and snake-like. All this is 
 ascertained from the ruins of skeletons found in the Coal 
 Measure shales. 
 
 The most characteristic and striking of all Coal Measure 
 types of animals was the Lab-y-rinih'-o-dont. In size, some were 
 as large as an ox, and larger. The head of one species was 
 three feet long and nearly two feet broad. The teeth of Laby- 
 rinthodonts, like those of all Amphibians, were conical, but 
 on making a cross section, the cement and dentine the two 
 substances of which the tooth is composed, are found intri- 
 cately infolded in a labyrinthine fashion, and hence the name 
 of this type. In some of the Labyrinthodonts, the figure was 
 somewhat frog-like, with hind limbs much the largest. Whether 
 they practiced leaping we do not know. That they sometimes 
 walked as quadrupeds is certain, for in some instances, their 
 footprints have been preserved on the surface of sandstones. 
 They were found, for instance, near Greensburg, Pennsyl- 
 vania, and also in other American localities. The print of 
 the hind foot is four-toed, with a thumb standing out at right 
 angles ; and the appearance is so much like that of the human 
 hand, that when the animal was only known from its foot- 
 prints, it was named Cheir-o-the '-ri-um or " hand- beast." In 
 
178 WALKS AND TALKS. 
 
 some Labyrinthodonts the head and some other parts of the 
 body were covered with sculptured bony plates. 
 
 Numerous remains of smaller Amphibians are found in 
 Nova Scotia, in company with numerous snail shells, in the 
 stump of an old SigiUaria. In the same situation were found, 
 also, galley-worms, scorpions, and spiders. These, undoubt- 
 edly, all served as food for the Amphibians. Nearly all the 
 forms of insect life are represented among the relics of the 
 coal epoch myriapods of various groups, scorpions and spiders, 
 cockroaches, dragon-flies and other netted winged insects, and 
 also a few beetles. But we find no remains of the highest 
 insects flies, butterflies, ants, wasps, and bees. Many insect 
 forms discovered are aquatic, and undoubtedly served as food 
 for fishes and Amphibians. 
 
 If we examine the limestones associated with other strata 
 in the Coal Measures, especially from Ohio westward, we find 
 them stocked with a rich and varied fauna of marine remains. 
 Besides numerous tribes and genera of sharks and ganoid 
 fishes, these limestones abound in corals, crinoids and various 
 families of univalve and bivalve molluscs. Oysters, however, 
 are almost or totally wanting ; and no fish remains resembling 
 the modern perch and whitefish occur. There is a strikingly 
 antique aspect to these relics. The affinities are with the old 
 forms which we shall next discover, and not with the forms 
 of the modern world. We have here penetrated to the records 
 of the Palaeozoic JEon. 
 
 XXXI. TERRIBLE KlSHES AND THEIR COM- 
 PANIONS. 
 
 REMAINS OF THE DEVONIAN AGE. 
 
 WE now descend another stage in our examination of the 
 strata and their contents. We come down to the Devonian 
 System. Do not think these rocks are everywhere covered by 
 all the later ones. In many regions they come to the surface 
 because none of the later ones are there present. But where 
 
TERRIBLE FISHES AND THEIR COMPANIONS. 179 
 
 the Devonian strata disappear they go under the Carbonifer- 
 ous strata ; and these go under all the newer strata which 
 may be present. Remember, however, as before said, that a 
 whole formation may be found missing in particular places. 
 Strata were deposited only where sea-bottom existed. If the 
 spot was uplifted so as to be dry land during a particular 
 age, the formation belonging to that place can not exist. 
 But if the spot became sea-bottom in the next age, the for- 
 mation belonging there was deposited, and it does not now 
 lie on the formation of next preceding age, but on the one 
 before that. 
 
 So do not imagine ourselves penetrating deeper and deeper 
 into the earth. We examine the systems of strata in the re- 
 gions where they come to the surface. We may presume 
 they continue under the newer formations to great depths ; but 
 I have the opinion that if we could follow them, they would be 
 found gradually growing thinner. 
 
 Let us begin by learning where the Devonian strata occupy 
 the surface. Nowhere in New England are they distinctly 
 revealed. Nor in any of the Gulf States. A belt of Devon- 
 ian strata stretches east and west through central and south- 
 ern New York, from the Helderberg Mountains to Lake Erie. 
 Thence it passes under Lake Erie and along both shores to 
 the extremity of the lake, and into south-eastern Michigan. 
 Here the outcrop divides; one branch passes south, through 
 the west center of Ohio to the Ohio River, and the other., 
 turning north, goes under Lake Huron and along its western 
 border to the Straits of Mackinac. This branch here bends 
 westward and south-westward, so as to underlie the central 
 and eastern part of Lake Michigan, and border that lake on 
 the east. This branch goes down through Indiana to the Ohio 
 River, at the Falls of the Ohio, lying along the eastern border 
 of the great Coal Field of Indiana, Illinois, and Kentucky. A 
 belt also extends from Rock Island, Illinois, north-westward 
 by Iowa City, through the state of Iowa. This system is found 
 also in Missouri, Kentucky, Tennessee, and other states. 
 
 There is a very useful key to the distribution of the rocks 
 
180 WALKS AND TALKS. 
 
 of any system. There is always a great limestone formation 
 from the middle to the upper part of the system not always 
 extending to the top of it and this is generally quite con- 
 spicuous, in consequence of its solidity and prominence and 
 great usefulness. The great central limestone mass of a system 
 may be traced through all the windings of its outcrop, by a 
 line of quarries and cliffs and rocky ridges. If you can say 
 where this conspicuous central limestone belt is located, you 
 can at once understand that the older strata of the system 
 must lie on the side from which the limestone dips, and the 
 newer strata must lie on the side toward which the limestone 
 dips. Now, the great limestone mass of the Devonian is the 
 Corniferous Limestone. Throughout the west, the overlying 
 Hamilton formation is also a limestone, though mostly shaly 
 at the east. The limestone mass, therefore, from Ohio west- 
 ward, is Corniferous-Hamilton. Some of the points where 
 the Devonian limestone mass rises conspicuously are the fol- 
 lowing : Syracuse, Leroy, Caledonia, Buffalo, Ingersoll, Lon- 
 don, Sandusky, Kelly's Island, Columbus, Monroe, Alpena, 
 Mackinac, Petoskey, Rock Island, Iowa City, Louisville. At 
 all these points we find a limestone of nearly the same age, 
 containing generally an abundance of marine fossils. The 
 corals are very conspicuous, and at the Falls of the Ohio, and 
 the head of Little Traverse Bay, appear to have been gathered 
 together in literal reefs. The former locality and its vicinity 
 4ias been a favorite collecting ground for many years, and 
 geologists are still, almost weekly discovering new species. 
 The latter locality is close by the new and favorite summer 
 resorts known as Bay View or Petoskey and Charlevoix. 
 
 At Petoskey and vicinity occur those exquisite coral masses 
 which are so extensively polished and sold to summer tourists. 
 The masses range from the size of a hickory nut to that of a 
 man's head ; but the most common are of the size of the fist. 
 They are shaped somewhat like cakes made in "patty pans." 
 The upper surface is covered with six-sided cells about a 
 quarter of an inch in diameter. A delicately crenulated wall 
 runs around each cell. In the middle of the cell appears to 
 
TERRIBLE FISHES AND THEIR COMPANIONS. 181 
 
 be a small cylindrical wall running down along the length of 
 the coral tube. Within this sinks a pit abruptly an eighth of 
 an inch. Really, however, there is no true inner wall. From 
 this apparent wall regular radial lines run to the outer wall. 
 These are the upper edges of vertical radiating plates called 
 septa, which extend the whole length of the coral tube. These 
 forms are beautiful enough without polishing. Still, certain 
 internal structures are by polishing, brought out with admir- 
 able clearness and beauty. For instance, if the cake is split 
 vertically and one surface polished, you see that the space be- 
 tween each two septa is divided from end to end by delicate 
 horizontal dissepiments, giving the whole polished surface the 
 appearance of a piece of very fine woven cloth. The dealers 
 in these specimens give them various names, some of which 
 are quite absurd. The scientific name of this species is A-cer- 
 vu-la'-ri-a Da-vid-so'-ni. The first word signifies a little hillock 
 or cake; the second, means Davidson's; and we might call it 
 "Davidson's coral-cake." This Davidson was a very distin- 
 guished English writer on fossil Brachiopods. It would not 
 be a great hardship for visitors to Petoskey to learn to call 
 this coral by its correct name. 
 
 This species is found in America nowhere except in the 
 Hamilton Group, which you will remember, runs into the 
 Corniferous Limestone. It is found nowhere in the world in 
 such beauty and abundance as on the south shore of Little 
 Traverse Bay. The perfect specimens occur imbedded in soft 
 blue clay forming beds ten or twelve inches thick between 
 sheets of solid limestone. One can extract them with the 
 naked hand. By Drift action these coral cakes have been 
 transported like bowlders, from the northern part of the state 
 all over the southern part. The same coral is found also near 
 Iowa City and sparingly at other localities. 
 
 There is another fine coral found on the shore of Little 
 Traverse Bay, which has been named Fav-o-si'-tes Al-pe-nen'-sis, 
 which means the " Alpena Favosite." Alpena is at the head 
 of Thunder Bay on the east shore of the state, and this coral 
 occurs very abundantly, also, in that region. It is shaped 
 
182 WALKS AND TALKS. 
 
 like a potato, roundish or oblong, and is covered all over with 
 small cell-mouths which are nearly circular in outline, but often 
 angular, from mutual crowding. When one of these coral 
 potatoes is split open-, and one surface polished, the tubes 
 which run down from the surface can be beautifully seen as 
 also the transverse divisions or tabukz, and the perforations or 
 pores along the outer walls of the tubes. 
 
 It is quite wonderful to see the number of parasitic crea- 
 tures which attached themselves to these and other corals. The 
 surface of Acervularia was sometimes a whole world. Here is 
 a little bivalve shell spreading its fibrous rootlets out to make 
 itself secure (Crania). Here are numerous little coiled shells 
 (Ser'pula) of the class of Worms. Here is a little coral con- 
 sisting of a branching chain of cornet-shaped tubelets attached 
 with the small end of each to the under side of its predecessor, 
 near the upturned aperture (Au-lop'-o-rd). There are half a 
 dozen species of these. One aggregated itself in dense, thick 
 masses. One was beautifully small and delicate. One was 
 extremely fine, almost like a spider's web trailing over the sur- 
 face really a distinct genus. Then we find patches an inch 
 in diameter and less, which look like films of varnish pricked 
 full of pin-holes at equal distances. There are coaser and finer 
 sorts (Fis-tu-lip'-o-ra and Gal-lop' -o-r a). Another incrusting 
 coral is like excessively fine lace (Mon-tic-u-lip'-o-ra). There 
 are many other attached organisms of less frequent occurrence. 
 I hope readers who visit Petoskey will take pains to look up 
 these interesting forms and learn their names. Petoskey is not 
 by any means the only region where most of them occur. At 
 Thunder Bay, on Partridge Point, is an amazing quantity of 
 delicate coral structures composed mostly of little bars, slightly 
 divergent, lying in one plane, and having cross-connections, 
 forming a structure in some cases like woven cloth, with open 
 meshes. One finds an amazing number of variations in de- 
 tails. I have picked out from this locality alone one hundred 
 different species of these (Fe-nes-tel'-li-dce) and related forms 
 (all Bry-o-zo'-ans). Then, at Widder in Ontario, we find a 
 regular bank of bivalve shells of a certain species (Spi-rif-e-ra 
 
TERRIBLE FISHES AND THEIR COMPANIONS. 183 
 
 mu-cro-na'-ta) called "petrified butterflies" by the boys of the 
 vicinity. The deposit has been cut through by the Great 
 Western Kailway. The Hamilton strata are almost every- 
 where well stocked with the treasures of the ancient sea ; and 
 I have observed that the small and parasitic species are more 
 abundant than in other formations. The greater part of the 
 good fossils found in the Drift of the north-western states are 
 derived from this group. 
 
 But after all, the most astonishing relics of the Devonian 
 Age are the fish-plates and fish-teeth found in the upper part 
 of the System. Some years ago, a German-American clergy- 
 man came to me with fine specimens of fossils from Ohio, 
 among which were teeth and jaws of fishes, which he had 
 laboriously worked out of concretions found in the vicinity of 
 Delaware, Ohio. The concretions were imbedded in shales 
 immediately above the Hamilton formation. This was Rev. 
 Hermann Hertzer ; and he urged with much persistence that 
 I undertake the description of the fossils. Knowing, however, 
 that Dr. J. S. Newberry was at work on fossil fishes, I finally 
 induced him to turn his fish-remains over to Dr. Newberry ; 
 and they now constitute a part of the palseontological collec- 
 tion of Columbia College. Dr. dewberry's description of these 
 and other Ohio fishes may be found in the first volume of the 
 Report on the Palaeontology of Ohio. The two principal genera 
 have been named Din-icti-thys (terrible fish) and As-pid-ich'-thys 
 (shield-fish). 
 
 The cranium of Dinichthys was composed of thick bony 
 plates, strengthened with massive internal arches, and was at 
 least two feet in length and the same in breadth. The jaws 
 have on their margins, near the middle, a number of conical 
 teeth soldered to the bone not inserted in sockets and at the 
 front of each jaw, two strong, curved, triangular teeth, inter- 
 locking together. These teeth are shaped from the solid bony 
 tips of the jaws. The body was protected by bony plates which 
 on the back were large and thick. The body must have been 
 about three feet in diameter, and its length from fifteen to 
 twenty feet. Other fish remains of the same age, named 
 
184 WALKS AND TALKS. 
 
 Aspidichthys belonged also to a bony plated fish as large as 
 Dinichthys; but its plates, as far as known, are covered with 
 large, hemispherical, smooth, enameled tubercles. 
 
 In the Corniferous Limestone we find also quite numerous 
 bones and teeth of fishes. They all belong, however, to those 
 orders which include the modern Sharks and Gar-Pikes or 
 Ganoids. No trace of soft-scaled fishes is certainly known 
 below the Mesozoic. Some of these sharks had enormous 
 bayonet-like spines inserted in front of certain of their fins ; 
 and the Ganoids were armed with strong, conical teeth, and 
 protected by bony enameled scales. 
 
 Every one has read or heard of the " Old Red Sandstone." 
 In some parts of this Scottish formation were found fish re- 
 mains which Miller described years ago, in a popular and fas- 
 cinating style which attracted much attention. This was one 
 of the earliest attempts to interest the public in fossil remains 
 and we might even add, in any branch of geology. Hugh 
 Miller was a mere quarryman, and Agassiz was so surprised to 
 find such a man doing good work in science, that his praise 
 contributed much to Miller's fame. The renowned fishes of 
 Scotland were mostly Placoderms, like Dinichthys. One of 
 them has been called Ceph-al-as'-pis (shield-head), for it had a 
 broad flattened head shaped like a saddler's knife in outline, 
 with a tapering conical body. Another is Pter-ich'-thys 
 (winged fish) since its only fins stood out at right angles like 
 wings. But no European fishes possess any greater interest 
 than our own. 
 
 XXXII. ANCESTRY OK THE PEARLY NAU- 
 TILUS. 
 
 SILURIAN REMAINS. 
 
 THE Pearly Nautilus still lives in the deep waters of trop- 
 ical seas. This is not the Paper Nautilus or Fairy Sailor, of 
 which Byron wrote: 
 
 " The tender Nautilus who steers his prow 
 The sea-born sailor of his shell canoe. 
 
ANCESTRY OP THE PEARLY NAUTILUS. 185 
 
 The ocean Mab, the fairy of the sea 
 
 Seems far less fragile, and alas ! more free. 
 
 He when the lightning-winged tornadoes sweep 
 
 The surge, is safe his port is in the deep 
 
 And triumphs o'er armadas of mankind 
 
 Which shake the world, yet crumble in the wind." 
 
 It was the Paper Nautilus the Argmauta Argo which 
 from the time of Aristotle was believed to come to the surface 
 and " spread to the wafting breeze a two-fold sail." Even 
 this pretty fancy has been dispelled by truth-loving science. 
 The Paper Nautilus, when it wishes to travel, simply folds its 
 arms together, and from its funnel squirts a stream of water, 
 like the most common squid, and makes " head way" back 
 foremost. Our Pearly Nautilus is a relative of this; but he 
 too, is no sailor. He can indeed float with all his tentacles 
 outspread, but his normal place is on the bottom of the sea, 
 and his normal gait is a sprawling crawl on a set of flexible, 
 slippery tentacles, with mouth to the ground and back up. 
 
 This Nautilus is the representative of a venerable dynasty. 
 The type is a survival from remote Palseozoic times. It per- 
 petuates a plan of structure so ancient that the bricks of As- 
 syria and the urns of buried Ilios are but memorials of yes- 
 terday. Its predecessors nay, perhaps truly, its ancestors 
 may be found lying in the tombs which every age of the 
 history of life and death has stocked with its memorials. The 
 Chambered Shell lies imbedded with its contemporaries in 
 strata of Carboniferous, Devonian, Silurian, and Cambrian 
 age. We have turned over their remains in searching for the 
 relics of those ages; but we have reserved to this time the 
 mention of this diversified type. But let us first glance at the 
 rocks which we are to explore. 
 
 We shall call them Silurian. Very commonly they are 
 known as Upper Silurian. They lie many thousand feet down 
 from the surface, in regions where the series of strata is com- 
 plete. But, in other regions, they rise up to sunlight and 
 atmosphere, with all their treasures of the ancient world em- 
 bosomed in their solid mass. Here, also, is a great limestone 
 
 16 
 
186 WALKS AND TALKS. 
 
 formation the Niagara Limestone. We find it at the Niag- 
 ara river, which gives its name. It is seen along the gorge 
 from Lewiston to the Falls. It is the top rock of this gorge, 
 and over its brink at the Falls, the vast body of water is pre- 
 cipitated. The reaction of the water against the underlying 
 shale wears it away. The limestone is undermined, and huge 
 pieces break off from time to time. So the Falls recede ; so 
 the gorge is continued backward ; so the seven-mile gorge was 
 formed; and we have recently ascertained that during thirty- 
 three years the recession has been three feet a year. 
 
 From the Falls eastward, this limestone continues its out- 
 crop to Rochester and beyond. Westward and northwestward 
 it trends toward Cape Hurd, a promonotory separating Geor- 
 gian Bay from Lake Huron. Continuing under the north- 
 ern part of Lake Huron, it forms the southern portions of 
 the Manitoulin Islands ; it borders the northern shore of Lake 
 Michigan; separates Bay de Noc and Green Bay from Lake 
 Michigan, and borders the western side of the lake to Chicago, 
 extending beyond and into north-western Indiana. From 
 north-western Illinois, a belt stretches north-westward diagon- 
 ally across Iowa. At Sandusky, Ohio, an area expands like 
 a great spatula over parts of Ohio, Indiana, and Kentucky, 
 stretching to the southern part of Kentucky. But through 
 the broadest part of this spatula is a great oval perforation, 
 within which are embraced Cincinnati, Richmond (Ind.), 
 Madison, Frankfort, and Lexington (Ky). On the great 
 Silurian mass of limestone are situated Rochester, Niagara 
 Falls, Milwaukee, Chicago, Joliet, Huntington (Ind.), San- 
 dusky. Next below the Niagara Limestone lies the Niagara 
 Shale, and then the Clinton formation ; but both of these be- 
 come limestones at the west, and unite with the Niagara lime- 
 stone to augment the central mass. Next above the Niagara 
 limestone comes the Salina formation, of shales, clays, and 
 marly limestones a formation which, as we stated in Talk 
 XXIII, yields the country a vast amount of salt and gypsum. 
 At the bottom of the Silurian are found two fragmental for- 
 mations, the Oneida Conglomerate and the Medina Sandstone 
 
ANCESTRY OF THE PEARLY NAUTILUS. 187 
 
 above it proclaiming intelligibly that the waters were dis- 
 turbed when the Conglomerate was deposited, more quiet 
 when the materials of the sandstone were laid down, and still 
 quieter when the fine sediments settled down which formed 
 the Clinton marls and the Niagara shale. Please bear, in mind 
 this law of the succession of different kinds of sediments. 
 
 Now let us examine the contents of these Silurian strata. 
 The geologist has been around with his hammer, and looked 
 them through and through. True, he has not broken to 
 pieces one-millionth of the Silurian rocks of the country ; but 
 he has broken an immense number of samples from many 
 localities and many horizons ; and we justly believe that the 
 system has been fairly probed. In the lowest beds the 
 Oneida Conglomerate nothing of much importance has been 
 found. This does not surprise us, for shells and corals must 
 have been ground to powder, had they been mingled with the 
 rolling stones of which that formation is composed. The 
 Medina sandstone was fine enough. to allow the accumulation 
 of some organic remains. We find small heaps of petrified 
 sea- weeds. One sort is regularly jointed, and presents a some- 
 what elegant appearance (Ar-throph'-y-cus). We are much 
 interested to be able to discover which way the currents set 
 over the soft sand. In New York it is common to find a 
 sandstone surface with a little shell lying, convex side up, 
 and beyond it a train or drift of sand a few inches long, and 
 diminishing to a point. How similar were the conditions 
 of the sandy beach then and now! How surprising that a 
 little ridge of soft sand formed millions of years ago, should 
 have been so carefully preserved through all the storms and 
 revolutions of the world to our day ! 
 
 It is in the limestones, and especially the Niagara Lime- 
 stone, that we find the relics of the ancestors of the Pearly 
 Nautilus. It may seem strange that most of them are straight 
 rather than coiled. But their structures are the same, and 
 the coiling is a circumstance. These straight nautiloid shells 
 we call Or-tho-cer'-a-tites (the technical name of the genus 
 being Or-ikoc'-e-ras or "straight horn"). Like Nautilus, the 
 
188 WALKS AND TALKS. 
 
 shell is divided by cross partitions or septa at frequent intervals. 
 Like Nautilus, it is a gradually tapering tube. Like Nautilus, 
 there is near the center of each septum, a small perforation 
 from which leads a little tube to the next septum, and thus 
 through all the septa and intervening chambers. This tube is 
 the siphunde. Like Nautilus, each septum is simply and 
 plainly concave with the concavity turned toward the larger 
 end of the shell. As in Nautilus, the last chamber is deep, 
 and undoubtedly this was the portion to which the animal 
 was confined. If Nautilus should be uncoiled, it would be 
 precisely an Orthoceras. 
 
 How the relics of these interesting creatures lie packed in 
 various parts of the Niagara limestone through all its conti- 
 nent-wide extent often broken, sometimes perfect. There is 
 no consciousness in these ruins now. We can picture them, 
 however, the homes of creatures which could feel and see and 
 hunger and desire, and entertain a purpose. We can think 
 back the wide-ten tacled bodies which rested in the outer 
 chamber. We can see them, in thought, spreading their 
 strong arms, glaring with their great glassy eyes, pursuing 
 with hungry ferocity their prey, tearing with their lance-like 
 mandibles, and feeding with the gusto and relish of a true 
 carnivore. 
 
 We notice among the dead chambered shells some varia- 
 tions. In form, a few are slightly bent, while most are 
 straight. In some, the traverse section is oval, while generally, 
 it is almost circular. In some, the place of the siphuncle, in- 
 stead of being central, is a little distance away from the 
 center but not in the margin. We notice, also, that the 
 septum is sometimes undulate around the margin, instead of 
 plane. Thus nature shows a susceptibility to vary. Her 
 forms are fashioned after fundamental plans, but not all cast 
 in one mould. For some reason which may be inscrutable, 
 she seems always playing off from the main path, with a 
 sense of freedom rather than necessity. 
 
 Right here, in the midst of these ancient Orthoceratites, 
 are the relics of organisms decidedly divergent. Here are 
 
ANCESTRY OF THE PEARLY NAUTILUS. 189 
 
 coiled chambered shells which almost any person would iden- 
 tify with Nautilus. They really have all the essential char- 
 acters of Nautilus; but you will notice that they are not 
 closely coiled ; we do not find each whorl overlapping and 
 concealing all the others ; and the last whorl is even a little 
 separated from the preceding one (Lit-u-i'-tes). Many others 
 are coiled, but somewhat loosely, and the siphuncle is one side 
 of the center sometimes close to the outer margin (Gy-roc'-e- 
 ras). Still others are curved enough to form one whorl, but 
 not properly coiled, and the siphuncle is close to the outer 
 margin (Cyr-toc'-e-ras). But we have not time to trace all 
 the varieties of the type of chambered shells even among 
 the Silurian limestones. We may have future opportunity to- 
 glance at the history of this type, and show the great improve- 
 ments made in complication and decoration, during the Meso- 
 zoic ages. 
 
 In strolling through the quarries excavated in the Niagara 
 limestone in the suburbs of Chicago, for instance, or at 
 Joliet or Waukesha our attention is constantly arrested by 
 the remains of shells, corals, and criuoids. The bivalve shells 
 are chiefly Brack '-i-o-pods. They are lower in rank than clams 
 and river mussels. They may always be known by having 
 the beak and hinge in the center of the valve, with the 
 valves presenting the same slope and curvature each way 
 from the beak. They may also be known by having one 
 valve more swollen than the other. Many also, have a deep 
 depression (Sinus) along one valve from the beak to the 
 opposite margin, and a corresponding elevation (Fold) in the 
 opposite valve. Brachiopods are now nearly extinct. The 
 univalve shells are mostly Gas'-ter-o-pods. These are higher in 
 rank than clams and mussels. 
 
 The Crinoids were plant-like forms (Zo'-o-phytes) but strictly 
 animals in nature. The most common kinds were rooted to 
 the muddy sea-bottom, as is proved by specimens quite abund- 
 ant in Niagara shales at Waldron, Indiana. The old roots 
 are found going down into the clay like the roots of an oak. 
 Above the root rises a stony stem, ten or fifteen inches high, 
 
190 WALKS AND TALKS. 
 
 and from an eighth to half an inch in diameter. This is simply 
 a pile of little button-like discs, each one with a hole through 
 the center, and some radial striae on the flat sides. So there 
 is a perforation through the whole length of the stem. Some- 
 times several of the segments remain attached together; but 
 generally, they are separated and scattered through the rock. 
 In some European countries they have long been known as 
 " St. Cuthbert's beads." We find them in great abundance 
 in the drift of the Northwestern States. At the top of the 
 stem we find a little urn composed of many stony plates 
 nicely joined together by their edges. The urn has a cover 
 similarly formed. Most of these bodies are found disjointed 
 in the rocks; but there is one which seems to have held 
 together very firmly (Car-y-oc'^ri-nus) and is found in the 
 Niagara strata almost everywhere. The external surfaces of 
 the plates of the cup are elaborately chased and embossed ; 
 but this I must tell you is not an armed and rooted crinoid ; 
 it is a Cystid, having no arms and with a tail-like stem. In 
 the true crinoids we find a row of arms generally ten rising 
 from the border of the urn or cup; and these often branch 
 or give off a delicate fringe. The arm and its subdivisions 
 are composed of flattened stony plates or pieces joined 
 together according to the general plan of the animal. 
 
 We thus see that when nature adopts a particular method 
 for the construction of one part of an animal, she pursues 
 faithfully the same method in the formation of all the parts. 
 Thus it appears that the works of nature are formed according 
 to plans. Any thing which is a plan has been thought out. 
 The plans of Nature are the expressions of mind. 
 
 THE KING CRAB'S 
 AND OTHER GRANDFATHERS. 
 
 CAMBRIAN FOSSLLS. 
 
 ONE who strolls along the coast of New England or the 
 contiguous islands will notice many things "cast up by the 
 sea," but one of the most interesting is the King Crab, 
 
THE KING CRAB'S GRANDFATHER. 191 
 
 lus Pol-y-phe-mus. It seems to be essentially a wide basin with 
 a small and spike-like handle. It is in fact employed by the 
 fisherman for removing water from his boat. The same objects 
 are strewn along the beach all the way to Charleston. A few 
 years ago, Professor A. S. Packard determined to make the 
 acquaintance of the King Crab family and study his pedigree. 
 He found very few printed documents on this strange subject, 
 and he therefore betook himself to a method of investigation 
 at which you will certainly be amused. He studied the King 
 Crab's eggs. He studied them seriously and thoroughly by 
 the aid of microscopes. More strictly speaking, he studied 
 the progressive development of the embryo within the egg. 
 He believed for many others so believe that the several em- 
 bryonic stages are pictures of the ancestors of the animal. He 
 believed that the first trace of an embryonic form would be a 
 picture of the remotest ancestor either in its embryonic or 
 adult stage ; and that the phases presented by the later stages 
 of the embryo would be pictures of later ancestors. I will 
 tell you what he found out, and you may believe that it 
 means what he says it does, or you may find out a more 
 probable meaning. 
 
 Professor Packard discovered that the earlier embryo of 
 the King Crab shows a striking resemblance to the early stages 
 of soft-shelled shrimps and low fresh water crustaceans now 
 living ; and that in a later stage, the embryo of the King Crab 
 was strikingly like certain Tril'obites found fossil in the Cam- 
 brian strata. There are at least three genera of such Trilo- 
 bites Ag-nos f -tus and Sa'-o from the bottom of the Cambrian, 
 and Tri-nu' '-de-us from the Upper Cambrian. Now, the mean- 
 ing of this is, according to some, that our King Crab is de- 
 scended from the same primeval stock as these trilobites; and 
 that all the trilobites were descended from that stock. This, 
 in fact, means evolution, and, we might as well say it at 
 once, that it means all the Crustacea have descended from 
 the same primitive stock. It is supposed that primitive crus- 
 tacean lived before Cambrian time. On this subject I do not 
 wish to say any more at present; but before we finish these 
 
192 WALKS AND TALKS. 
 
 talks, I will give you a fair and simple explanation of the 
 famous theory of Evolution. 
 
 But what are Crustaceans ? Aquatic animals covered by a 
 crust which is composed of a series of segments or rings joined 
 by their edges; and having more than eight feet. Of these, 
 Lobsters and Crawfishes are examples. And what are those 
 Trilobites ? They are crustaceans in which the body is divided 
 lengthwise by two grooves, into three lobes the axis running 
 along the middle, and a lateral lobe each side. The Trilobites 
 were very ancient animals. I say " were," because the last of 
 them perished millions of years ago, during the progress of'the 
 Carboniferous Age. Here are the tombs of their remotest an- 
 cestors. Here lie their forms imbedded in these primordial 
 sandstones and slates. 
 
 Let me explain about these sandstones and slates. At 
 Potsdam, in northern New York, and throughout that vicinity, 
 a gray sandstone lies at the surface the same as referred to 
 in Talk XIX. It stretches across the St. Lawrence River, 
 and north-eastward along its valley. It encircles the Adiron- 
 dack highlands. This is the Potsdam Sandstone. Westward 
 it stretches through Canada to the Sault Ste. Marie, and along 
 the south shore of Lake Superior to Keweenaw Point. The 
 "Pictured Rocks" are part of it. Southward from this shore 
 it disappears under the Trenton Limestone. It is the Potsdam 
 Sandstone which forms the lower portion of the high cliffs 
 along the Upper Mississippi River. It is in this sandstone 
 that multitudes of these ancestral Trilobites lie packed away. 
 They have had a hard time, however. They are all in pieces, 
 and it is difficult to get sufficient pieces together to describe 
 any one of the species. The sands from which this sandstone 
 was formed must have beaten to and fro in shallow water, or 
 along some beach for many years. These trilobites are but a 
 few inches in length. 
 
 Besides Trilobites, we find in the Potsdam Sandstone, many 
 remains of little bivalve shells called Lin'gula. This is a genus 
 of Brachiopods, a low class of Molluscs. The name signifies a 
 "little tongue," referring to the shape. This is a remarkable 
 
THE KING CRAB'S GRANDFATHER. 193 
 
 genus, for it has been in existence on the earth from the epoch 
 of the Potsdam Sandstone to the present. In every formation 
 are some species of Languid ; and living species may be found 
 along our Atlantic coast, clinging by their fleshy peduncles to 
 the wharves and other supports. Another remarkable fact 
 about Ijingula is this : Its shell is composed largely of bony 
 substance phosphate of lime while the, shells of ordinary 
 molluscs are composed of stony substance carbonate of lime; 
 and this peculiarity of constitution has clung to this little type 
 through all the ages. 
 
 It is a peculiarity of Brachiopods to have the two valves 
 unequal; one is more convex than the other. The more con- 
 vex valve has also the more projecting beak. But each is 
 symmetrical taken by itself. That is, if you lay it down on 
 the side, you see the beak in the middle, and on each side of 
 it, the outline of the valve presents the same shape and curve. 
 Now, the clam and river mussel are quite different. In these, 
 the two valves are equally convex; and, if you consider one 
 valve by itself, it is not symmetrical. That is, if you lay a 
 valve down on its side, you find the beak nearer one end; 
 and the slope of the shell-outline is not the same on each side 
 of the beak. Shells of this sort belong to the class La-md'-li- 
 branchs. All the difference in the forms of these two classes 
 arises from the position of the animal in the shell. In the 
 Lamellibranchs, one valve is on the right side and the other 
 on the left. So the principle of bilateral symmetry makes one 
 valve the counterpart of the other. In the Brachiopods, one 
 valve is on the back and the other over the abdomen. So 
 the principle of bilateral symmetry does not operate between 
 the two valves; but the right and left sides of each valve 
 separately are symmetrically developed. By bilateral sym- 
 metry we mean the law or principle which causes every fea- 
 ture of the right side of an animal to have a corresponding 
 feature on the left side. This principle runs through the 
 whole animal kingdom. Even among the star-fisheSj crinoids, 
 corals or other so-called "radiate" animals, we can draw a 
 line which will separate right and left sides. Try it in a star-fish. 
 
 17 
 
194 WALKS AND TALKS. 
 
 The Potsdam Sandstone from northern New York to Min- 
 nesota appears to be the lowest formation above the Eozoic 
 crystalline rocks. The copper-bearing rocks are older, but it 
 is not yet decided whether we should regard them as embraced 
 in the Palaeozoic System or not. There is also, in Wisconsin 
 and Minnesota, a massive quartzite formation underneath the 
 Potsdam Sandstone; but as it is not fully proved to contain 
 any fossils, we are not certain whether to call it Eozoic or not. 
 But in Vermont, in eastern Massachusetts and in New Bruns- 
 wick, are slates which underlie the Potsdam and contain fos- 
 sils. ( ' l Acadian " or " St. John " Group) . Some of these were 
 Trilobites ten to twenty inches long. 
 
 Down in these lowest Palaeozoic strata we find also, other 
 remains of animal types. Here for instance, are " chambered 
 shells " the grandfathers of those described in the last Talk. 
 We find here Or-ikoc'-e-ras, as well as some marked deviations 
 from it. Here are the oldest examples known of this type. 
 Here, we might say, was its first introduction to the world ; 
 and we might begin to query how it came here. We should 
 be inclined to think it was an abrupt introduction, without 
 predecessors gradually more and more simple as we should trace 
 them into remoter ages. If an abrupt "introduction, it was 
 not an evolution from some older form, because evolution pro- 
 ceeds by gradual transitions. Such is the conclusion of some 
 scientific men ; and if we were obliged to form a conclusion 
 on the whole question from the facts connected with the first 
 appearance of chambered shells, I think we should all say 
 they did not appear according to the method of evolution. 
 We must be candid, however, and consider all the circum- 
 stances. We only wish to ascertain how the facts were not 
 to make ourselves think them different from the reality. If 
 chambered shells appeared according .to evolution, that is the 
 thing we want to know ; and it would be a pity to make ourselves 
 believe something not in accordance with God's ordination of 
 things. Now we know full well that the rocks older than the 
 Cambrian have been subjected to such actions since they were 
 deposited as ocean-sediments, that their aspect is totally trans- 
 
THE KING CRAB'S GRANDFATHER. 195 
 
 formed. We may feel confident that if any shells or corals 
 had been originally inclosed in the sediments, they would 
 have been destroyed. Especially would carbonate of lime 
 have disappeared. Therefore, we are not certain that no cham- 
 bered shells existed before the Cambrian. They may have 
 existed. They may have been so formed and constituted as 
 to show that the Cambrian species were not suddenly intro- 
 duced, but made their appearance in such graduated succes- 
 sion as evolution implies. Here, at least, is a possibility 
 which prevents us from feeling confident that the Cambrian 
 Orthocer'atites were introduced by a sudden creation. 
 
 In these lowest Cambrian strata are, also, still other forms. 
 Here we find Gas'-ter-o-pods univalve shells coiled up. These, 
 too, are well advanced from any humble beginning of Gas- 
 teropods in case they began in a humble way. The same 
 queries arise as in the case of chambered shells. Now, to 
 recapitulate, we find in these lowest, fossil-bearing strata, re- 
 mains of several types of animals appearing to our knowledge 
 for the first time, but all well advanced beyond the lowest 
 grades of the orders to which they belong. Here, in the very 
 lowest strata, are Trilobites ; Lingula and some related genera 
 of Brachiopods, as well as OS-this, quite a different genus, and 
 perhaps Worms. In the Potsdam Sandstone are, also, Trilo- 
 bites, as well as other crustaceans, Grap' '-to-lites (branching plant- 
 like animals with a horny skeleton), Sponges (of calcareous 
 kind), Lingula and other Brachiopods; Pteropods; Gastero- 
 pods and Orihoceras. I enumerate them simply to make clear 
 the fact that at the very dawn of the Cambrian Age numer- 
 ous types well advanced in rank, suddenly appeared. You 
 will notice, however, that several important types of animals 
 were absent. Here were no corals, no crinoids, no Bryozoans, 
 no Lamellibranchs. 
 
 So far we have confined our attention to the lowest group 
 of the Cambrian rocks, composed of the Acadian or St. John 
 formation and the Potsdam Sandstones. Next above the Pots- 
 dam is the Calciferous formation. It is very conspicuous 
 along the bluffs of the Upper Mississippi, where it forms gen- 
 
196 WALKS AND TALKS. 
 
 erally the upper half. Like the Potsdam Sandstone it is 
 huffish in color, and disposed to crumble to pieces. In the 
 north-west it is known as the Lower Magnesian Limestone. It 
 contains the lead mines of Missouri (Talk XXI). Above this 
 comes the St. Peters Sandstone, white, clean, and destitute 
 of fossils ; but this is not known at the east. Next is the 
 Trenton Group, which contains the great Trenton Limestone. 
 Like the other great central limestone masses (Niagara, Cor- 
 niferous, Lower Carboniferous) this forms a conspicuous land- 
 mark across the country, and constitutes the rich repository of 
 the remains of the animals which dwelt in the Upper Cam- 
 brian ocean. This limestone mass forms the bluffs at St. Paul 
 and Minneapolis; comes up on the north side of the Mani- 
 toulin Islands ; stretches westward across Ste. Mary's river, and 
 running through the Upper Peninsula of Michigan, goes down 
 along the west side of Green Bay, into southern Wisconsin, 
 northern Illinois, and north-eastern Iowa, holding the lead 
 mines in these three states ; outcrops over a large area about 
 Cincinnati, extending to Madison and Richmond, Indiana, and 
 Frankfort and Lexington, Kentucky ; outcrops again at Nash- 
 ville and surrounding region ; stretches through central New 
 York to Watertown, and across the St. Lawrence to Georgian 
 Bay, stretching along its eastern shore and emerging again at 
 the Manitoulin Islands. Everywhere, this group of limestones 
 and shaly limestones is wonderfully rich in the remains of 
 creatures which swarmed in the seas of the twilight ages of the 
 world. Most delicate structures, most exquisitely preserved, 
 which never cease to excite our admiration and our wonder. 
 Many a geologist has devoted a large part of his lifetime to 
 their study, and it seems a pity that we must pass them by 
 with a simple mention. 
 
EARTH 's DEEPEST GEAVES. 197 
 
 XXXIV. EARTH'S DEEPEST GRAVES. 
 
 THE EOZOIC ANIMAL. 
 
 WE are down now, on the bottom rocks of the earth's crust. 
 This is the home of the vitrified and crystalline bowlders 
 which overstrew the surface. There are fifty thousand feet 
 of later strata resting above these rocks in regions where the 
 series is complete. But here, and over extensive regions, the 
 deep Eozoic beds have been arched up to the surface, and no 
 newer rocks have ever formed over them ; or if they were, 
 have subsequently been worn away. Luckily for the geologist, 
 the modern sun-light has been let into them, and we have 
 gained some general knowledge of them, though [it must be 
 confessed, a very great amount of ignorance remains. Let us 
 see what has been found out. 
 
 In the first place, deep as we have ever penetrated into 
 these Eozoic rocks, they all retain some traces of stratification. 
 In most cases, the stratification is very obscure; in many 
 cases, it is quite obliterated, but rocks of this sort furnish some 
 evidence of their original bedding. Often they differ from 
 stratified rocks in no other particular. Sometimes we can trace 
 them into continuity with stratified rocks. In all cases the 
 crystals which they contain, and the crystalline condition of 
 the rocks indicate solidification from a state of solution or soft- 
 ening which requires the presence of water. Grant us water 
 and heat, and the present condition would be produced from 
 ordinary ocean sediments. We must look upon all these rocks 
 as ocean-born. Hard and crystalline as they now are, we must 
 think of them as at one time in the condition of ocean-slime. 
 These rocky beds have been successively ocean bottom. These 
 rocks too, have successively rested as sediments upon an ocean- 
 bottom preexisting. There must have been an ocean-bottom 
 for the very first sediments to rest on. Let us remember this. 
 
 In the next place, the very oldest rocks known are granites, 
 syenites, gneisses, and hornblendic schists. Not having seen 
 the bottom of this series, we can not state its thickness. At 
 a higher level, have been found, in the north-west, conglom- 
 
198 WALKS AND TALKS. 
 
 erates, quartzites, and marble, all together attaining a thickness 
 of one thousand to six thousand feet. Then come various 
 schistose "rocks and diorites ; and about here occur great beds 
 of haematite or iron ore. This series is four thousand or five 
 thousand feet thick. Next above are black slates and schists, 
 often ferruginous, and other diorites, making about twenty-six 
 hundred feet more. Next, are five thousand feet of mica schists, 
 and finally, several hundred feet of granite and gneiss and kin- 
 dred rocks. These rocks altogether aggregate a thickness not 
 exceeding twenty-five thousand feet. But this may not embrace 
 all. In Canada, Sir William Logan computed the Eozoic rocks 
 as fifty thousand feet thick, and that estimate is generally 
 adopted. The thing of chief importance here, is to know that 
 the thickness is great, and the rocks are all crystalline. 
 
 Now, we explore these old rocks from bottom to top, and 
 scarcely find a trace of organic remains. Who could expect 
 fossil shells or corals imbedded in hard rocks consisting of frag- 
 ments of crystals and grains of quartz, feldspar, mica, and 
 hornblende? The nature of the rock proclaims changes in 
 constitution which must have dissolved or destroyed all relics 
 of the hard parts of animals. Here must be some lost chap- 
 ters of the history of life the first chapters in the volume. 
 It is like the loss of the Alexandrian Library. Could the 
 records of those earliest ages be restored, how many outstand- 
 ing doubts and irresolvable problems would be disposed of! 
 But since the records are wanting since the records may be 
 regarded as lost, we must proceed not as if the records never 
 existed, but by some rational process to reproduce the records. 
 From the bottom of the Cambrian up, we have learned well 
 the general tenor of the history of life. We must project that 
 tenor backward toward a lost beginning. When the death of 
 Dickens, in 1870, left "The Mystery of Edwin Droud" an 
 unfinished tale, it was considered not impracticable to devise 
 concluding chapters which should carry out the tenor of the 
 work as revealed in the written chapters a conclusion which 
 should form a unity with the portion in which the author had 
 divulged his plan and purpose. By the same principles the 
 
EARTH'S DEEPEST GRAVES. 199 
 
 lost chapters at the beginning of the story of life may be 
 plausibly restored ; and this course is infinitely wiser than to 
 sit by and hug our ignorance, or deny that any chapters have 
 been lost, and proceed to argue as if we had the whole history. 
 
 But thanks to the Canadian geologists, the first chapters 
 are not completely lost. We have a fragment of a page ; and 
 we know about where in the book it belonged. In the lower 
 part of this vast series of rocks are in Canada three great beds 
 of marble or crystalline limestone. In the third, or upper 
 one, occur some forms which appear to be organic. These 
 were brought to the notice of the scientific world in 1856. 
 They have been studied by mineralogists, palaeontologists and 
 chemists. They have been subjected to most searching mi- 
 croscopic study. The general opinion is that they are organic 
 remains ; and they have by general consent been referred to 
 a group of organisms of low grade called Fo-ram-i-nif'-e-ra 
 the same as that to which Globigeri'na belongs (Talk X). 
 A few mineralogists regard them as inorganic. These forms 
 have been obtained at several localities in Canada, as also, in 
 New York, near Troy, in Ireland, in Bohemia and else- 
 where. They contain certain features which, in my opinion, 
 could not be regarded as of mineral origin. On the con- 
 trary, they closely resemble some structures found in certain 
 Foraminifera. 
 
 In the mass, we notice a concentric or laminated structure, 
 as if the organism were formed of numerous layers wrapped, 
 one about another. These layers, in most cases, consist alter- 
 nately of serpentine and carbonate of lime. The serpentine, 
 as is believed, occupies the place of the fleshy part of the 
 animal, while the carbonate of lime is its skeleton ; and we 
 may speak of it as coral, for in many respects it was like 
 coral, though produced by an animal much lower in rank 
 than the polyps which secrete true coral. When we prepare 
 extremely thin slices of this skeleton, some minute structures 
 are seen under the microscope, which convince us of their 
 animal nature. The name of this creature is E-o-zo'-on can-a- 
 den'-se or the "Dawn Animal of Canada." 
 
200 WALKS AND TALKS. 
 
 Now, if we understand correctly the nature of this animal, 
 it was related to A-mce'-ba, a minute soft creature often found 
 in stagnant fresh waters. Those who use the microscope to 
 search for animalcules may sometimes discover in the field of 
 view, a little shapeless lump which seems like a particle of 
 dirt, except that it is partially transparent. While wishing 
 it out of the way, it is seen to move. On one side is extended 
 a little arm or tentacle ; it is then withdrawn. But suddenly, 
 one or two others are protruded ; and we find that the crea- 
 ture generally keeps two or three tentacles extended. But one 
 or all may be very capriciously withdrawn ; and when with- 
 drawn, it is impossible to trace any outline of them. The 
 tentacles melt into the general substance of the body. In 
 the interior can be seen what is called a "nucleus" and a 
 " contractile vesicle." 
 
 Attending carefully to the movements of Amceba, we dis- 
 cover that they have an end in view. The tentacles are ex- 
 tended in search of food. This animal is hungry. It is con- 
 scious of hunger. It knows how to secure food. It has a 
 will which sets its organs in motion. It knows how to seize a 
 particle of food. See! its arm is wound about a minute ani- 
 malcule; it holds it, but now, it does not convey it to the 
 mouth. Where is the mouth ? In truth, there is none. The 
 arm is absorbed animalcule and all. It disappears in the 
 common mass of jelly, and the animalcule is seen within it. 
 So this creature feeds. It gets around its food successfully ; 
 but it simply pours itself over it. What an amazing simplicity 
 of structure is here ! Indeed, there is no structure ; we have 
 little more than a shapeless particle of jelly. Whenever the 
 animal takes breakfast, it extemporizes an arm for seizing it. 
 Whenever it eats, a mouth is extemporized for admission of 
 food, and a stomach is extemporized for receiving and digest- 
 ing it. From all the ailments of hands, mouth, teeth, and 
 stomach this animal is happily free. Exempt from headache, 
 sore eyes, ringing ears and heart-flutterings, it still exercises 
 all the functions requisite to make it an animal. 
 
 And this modern creature is the representative of Eozoon. 
 
EARTH'S DEEPEST GRAVES. 201 
 
 But Eozom could not be placed defenseless in the sea. A 
 little lump of jelly would be swept into annihilation by the 
 force of the waves. Eozoon, however planted, held fast to its 
 support, and immediately secreted a strong roof over him for 
 protection. A thousand little holes through the roof allowed 
 threads of its gelatinous substance to be protruded. These 
 coalesced in a common film which spread over the roof like a 
 coating of tar. This was unprotected, and a second and 
 higher roof was built. The structure was now two stories high. 
 Through the upper roof innumerable minute perforations al- 
 lowed the jelly of the second story to be protruded in fine 
 threads, and these in turn coalesced, and a third roof was se- 
 creted. Thus the process continued, and the structure be- 
 came many stories high. Meantime other individuals were 
 planted by this, or near this, and by and by, they were so 
 enlarged that they grew together, and grew as one animal. 
 So hundreds and thousands of animals grew together and con- 
 tinued to grow and enlarge the structure during, probably a 
 thousand years. 
 
 As time passed on, this organism grew old and effete. The 
 life-time of its species was drawing to a close. It was destined 
 to be replaced by something better suited to the improved cir- 
 cumstances of the world. All the time, however, the sedi- 
 ments had been gathering about the bases of the rising reef- 
 mass as the dust of time accumulates about the temples of 
 the ancient cities. As they become buried and forgotten, so 
 the eozoonal reef-structures were buried and forgotten buried 
 thousands of feet deep buried in sea-sediments which became 
 stone. Then the seons of the world continued to roll by. 
 Oh, what a varied history was enacted while the tombs of 
 Eozoon remained silent and undiscovered ! 
 
 In the Age of Mind, a marble edifice was demanded to 
 meet some want of civilization. The primeval tomb was 
 opened by the quarryman, and there rested the relics of the 
 first inhabitant of our globe. It is that of which we have 
 been speaking. 
 
202 WALKS AND TALKS. 
 
 . AN EARLIER 
 
 INTIMATIONS OF A FIERY JEON. 
 
 WE are searching for a beginning. We have followed 
 down the succession of formations to what seems a foundation ; 
 but we perceive this must rest on something which already 
 existed; it can not be the beginning. It is an ocean-born 
 mass of sediments. The ocean preceded the sediments. Some- 
 thing for the ocean to rest on preceded the ocean ; what was 
 that ? Not something born of ocean. What existed before 
 ocean and ocean sediments ? 
 
 You have just seen (Talk XXXIV) that the deepest rocks 
 are hard and crystalline. We have concluded that their con- 
 dition has probably resulted largely from the action of water 
 and heat. Water alone would not dissolve the substances of 
 which these crystals are composed ; but heated water would be 
 much more efficient. Moreover, the addition of alkali to the 
 heated water would enable it to dissolve nearly all the sub- 
 stances in these lower rocks. However mud-like or sandy the 
 sediments originally were, heated alkaline waters would dis- 
 solve them; and then, if the solution were allowed to cool, the 
 various constituents would enter into such combinations as 
 suited their several affinities for each other. So the resulting 
 state of the materials would be extremely different from that 
 of the original sediments. This is at least a part of the pro- 
 cess called metamorphism of the rocks a subject to which 
 your attention has been many times called, and a cause of the 
 disappearance of any organic remains in rocks thus meta- 
 morphosed. 
 
 But in this connection, the important point is the evi- 
 dence of ancient heat universally extended. I do not suppose 
 the metamorphism of the rocks has taken place at the surface. 
 The heat engaged seems to have been interior heat. It was 
 shut in and retained for ages by overlying masses of strata. 
 And yet I doubt if all metamorphic regions now exposed have 
 been formerly covered. Much yet remains to be learned about 
 metamorphism. 
 
AN EARLIER BEGINNING. 203 
 
 That the heat was internal is evinced by many proofs of 
 the continued existence of internal heat. You will recall the 
 facts cited in Talk XVII. You will recall the phenomena of 
 geysers and hot springs (Talk XIV). You will remember that 
 lavas from volcanoes come up from some heated interior (Talk 
 XV). Your thoughts will again glance over the thousands 
 of square miles of surface covered by lavas which issued 
 through fissures in the Age preceding the present (Talk XVI). 
 You will be vividly impressed with the .conviction that in- 
 tense, fusing heat exists within the earth ; and since all heat 
 tends to waste away, you will conclude that the earth's surface 
 temperature was much higher some millions of years ago than 
 it is at present. The wastage of the earth's heat is proved by 
 actual observation. Science has measured the amount of heat 
 which comes to the earth annually that is, the amount on 
 each square yard and has also measured the amount which 
 escapes annually ; and it is thus shown that the wastage ex- 
 ceeds the receipts. The earth is growing cold. This great 
 fact is established by experiment, by observation on the escape 
 of heat from within, and by the records of an ancient higher 
 temperature than now exists at the surface. 
 
 Cooling off"! That disclosure puts our minds in a new atti- 
 tude toward the world's history. We have to contemplate the 
 earth as a cooling globe. That points our thoughts backward, 
 along a progress of cooling. That summons us to consider what 
 conditions of the world must have been passed in the progress 
 of cooling. By all the evidence that progressive cooling has 
 been a fact, we are authorized to reason out the events of the 
 cooling history. 
 
 Not the slightest evidence exists that the laws of heat are 
 different under our observation, from the laws which controlled 
 the cooling of the ancient world. We know what they are, 
 and what they were. It is as safe to base backward calcula- 
 tions on them as to base forward calculations on the planetary 
 movements which bring conjunctions and eclipses. We are 
 on the safe ground of reason and science ; we are not soaring 
 on the wing of imagination. We are not calculating events 
 
204 WALKS AND TALKS. 
 
 in which human caprice could have intervened. We are not 
 romancing ; we argue from cause to effect. 
 
 This is the way reasoning leads us : Following the course 
 of cooling backward, we arrive at a time such that water could 
 not have existed on the earth. All the water of the earth 
 must have been vapor or gas suspended in the atmosphere. 
 At a time when no ocean had existed, no ocean-sediments had 
 been deposited, all those rocks which have resulted from 
 marine sedimentation were yet non-existent. The earth had 
 probably a solid surface of some kind ; but to emit heat suffi- 
 cient to hold all the water of the world in an uncondensed 
 state, the temperature of the surface must have been high 
 perhaps a glowing temperature. 
 
 But even here we are in the midst of a cooling process. 
 Why not? Who can affirm that the world began to exist as 
 a red-hot body ? You know that red-hot matter may be made 
 white-hot; and then by increase of heat, may be rendered 
 liquid. We must trace this history back to a molten world. 
 
 Is there now any ground for refusing to trace the history 
 farther back ? This is a cooling process. There is no certain 
 beginning for a cooling process except in a temperature so high 
 that the heated matter exists as a mere vapor, or perhaps gas. 
 There is no known remoter condition of matter, though we may 
 conceive the temperature indefinitely high. It is, let us say, 
 the remotest condition which we seek. Now all terrestrial sub- 
 stances are capable not only of fusion, but of volatilization. 
 Iron and the other metals have been reduced to vapor. So, 
 by reversing conditions, all gases may be liquefied and then 
 consolidated. Carbonic acid, oxygen, nitrogen, chlorine, 
 have been made solid. The form under which matter exists 
 is a circumstance depending on temperature and pressure. 
 There is no inherent improbability that all the matter of the 
 world was once so heated as to exist in the form of vapor, or 
 even of gas. Before our eyes worlds are existing in those 
 states. 
 
 We should distinguish between vapor and gas. Gas is dry, 
 like atmospheric air like steam in the boiler ; vapor is com- 
 
AN EARLIER BEGINNING. 205 
 
 posed of minute liquid particles floating in a gaseous medium 
 like the cloud of steam condensed in the air after escaping 
 from the boiler. There may be mineral vapors as well as 
 igneous vapors. Most mineral vapors must be intensely heated. 
 We may call such a vapor "fire-mist." If the earth were 
 vaporized by heat, to what limits in space would the vapor 
 extend? We must think of that. If the earth was ever a 
 fire-mist globe its dimensions were vastly greater than at 
 present. 
 
 There is another thought to be mentioned here. The earth 
 is only one of a system of worlds, and there is good reason for 
 believing that any remote origin which we can establish for 
 the earth must represent the remote origin of the other planets. 
 In saying they are one system, I refer to their common motions 
 about one sun ; to the common elliptic form of their orbits ; to 
 the fact that all move from west to east; that all revolve 
 nearly in one plane ; that, so far as ascertained, they all rotate 
 on their axes ; and all rotate from west to east ; that the forms 
 and movements of all, and of all the satellites, are conformed 
 to one set of laws, and that all we know of other planets, 
 points to a fundamental correspondence and identity between 
 them. 
 
 This conclusion vastly enlarges our field. We must think 
 of each of the planets heated up to a fire-mist condition. It 
 is easier to think the sun also heated to such condition, since 
 he is at present not so far removed from it as the planets. 
 Now, when all these bodies were in that heated condition 
 which maintained them in a fire-mist state, the whole space of 
 the solar system must have been filled with fire-mist. Notice, 
 that I do not say it was fire-mist of any specified density. 
 The density of vapor depends on the proximity of the liquid 
 floating particles, to each other. There may have been a 
 diffused very thin gas also, in which the liquid particles 
 floated. Still, I do not conceive such gas necessary. These 
 particles some of which may even have been solid would 
 have weight smaller than imagination can conceive. They 
 were not particles like those of our clouds, influenced by the 
 
206 WALKS AND TALKS. 
 
 powerful attraction of a vast globe of matter not half a dozen 
 miles distant, and hence needing some buoyant support. These 
 fire-mist, and perhaps solid, particles were attracted only by 
 each other, and by the great common aggregation of particles. 
 For the particles in the neighborhood of the center of the 
 aggregation, the attraction would be nearly equal in all direc- 
 tions. For particles millions of miles away, an excess of 
 attraction toward the center would be felt; but the force 
 would be inconceivably small. So the mist particles were 
 practically suspended in space and required no gaseous 
 support. 
 
 The cooling history can be traced no farther back. Such, 
 probably, was its beginning. But I do not assume that the 
 matter of our system was originated in this state. We may be 
 able to trace out some remoter antecedents ; but if that can 
 not be done, I am perfectly prepared to admit that matter 
 may have entered existence as a fire-mist. However it origi- 
 nated, the temperature implied in fire-mist is as natural and in- 
 herently probable as any lower or higher temperature. Tem- 
 peratures are merely circumstances. Whatever temperature 
 prevails anywhere, things adjust themselves to it, and that 
 is natural. 
 
 Now, another thought is in every reader's mind. This 
 point has been reached as a beginning of a history of cooling. 
 
 From this point a natural process of cooling brings to pass 
 all the events in our system's physical history all the events 
 in our world's history. We are proposing to show this, and 
 trace the evolution in its general outlines. Now you shrink 
 back and exclaim "Evolution? Fate! Atheism!" That, my 
 dear friend, shows your total ignorance of the nature of 
 evolution. 
 
 Be calm. God was in the beginning, is now, and ever will 
 be. God originated; God controls; God is in the midst of 
 his works. Suppose we call the fire-mist the absolute begin- 
 ning ; there are certainly three things which are not fire-mist, 
 and require explanation infinitely more than a fire-mist condi- 
 tion of matter. Without these three things, there would 
 
AN EARLIER BEGINNING. 207 
 
 never be a cooling history. These things are : 1. MATTER 
 regardless of its condition. 2. FORCE and that in its vari- 
 ous forms. 3. METHOD or every thing would be plunged 
 in chaos, and forever remain there. These things imply 
 Power, Intelligence, Self-determination. Where self-determin- 
 ation is present, there is Personality. While the origination 
 of Matter, Force, and Method remains, there is still need of a 
 Creator. These three things originated, were the world to 
 run down like a clock, we should be compelled in reason to 
 ascribe its whole cycle of changes to the primordial activity 
 of a Creative Being. For myself, this conclusion is infinitely 
 short of satisfactory, as I shall explain in due time. But 
 even this is a theistic view of the origin of the world. 
 
II. 
 
 HISTORICAL GLIMPSES? 
 
 OR, 
 
 STORY OF THE WORLD SET IN ORDER. 
 
 XXXVI. GATHERING* WORLD 
 
 WANDERING GERMS OF WORLDS. 
 
 IT will be interesting to inquire what matter was before it 
 was fire-mist. If we can think out any movements or actions 
 of matter in any form which, under the laws of nature, would 
 tend to bring it to a state of fire-mist, then we ought to ascer- 
 tain if matter exists or has ever existed under such circum- 
 stances as to possess such movements and exert such actions. 
 If we find such movements and actions in real existence, then 
 some matter is now tending toward a state of fire-mist, and it 
 is reasonable to assume that the fire-mist in which the great 
 cooling process started, may have originated in the way indi- 
 cated by what we see. In another work ("World Life"), I 
 have entered into some details on this subject; but it will be 
 understood that the inquiry is largely a speculation, though 
 suggested, shaped, and guided by what we know of the laws 
 of matter, and observe taking place in the universe 
 around us. 
 
 Comets are facts of observation ; there is no mistake as to 
 the real existence of such bodies, whatever they be. They 
 always excite our admiration. They are full of wonder. They 
 come from the unsearchable depths of space, and after shining 
 in our heavens a few weeks, disappear in the unsearchable 
 depths. What is their origin? What their end? Think 
 of the approach of one of these mysterious messengers 
 208 
 
GATHERING WORLD STUFF. 209 
 
 from the infinite. Before discernible to unaided eyes, the 
 astronomer with his instrument detects it as a faint luminosity 
 just appeared. For weeks he watches its changes. Nightly 
 it grows brighter. It is approaching ; it will arrive. Like 
 the head-light of a locomotive seen at first as a luminous 
 point in the far distance, over some miles of track, gradually 
 growing brighter with no other evidence of motion with 
 brightness at length increasing in accelerated ratio, then daz- 
 zling us by its glare, and finally thundering past with a veloc- 
 ity which appalls, and retiring into the night which reigns in 
 the opposite direction so comes the head-light of a train of 
 cosmical matter; so grows its luminosity; with such a stun- 
 ning demonstration of physical power it rushes past us, and 
 sinks into infinite distance in another quarter of the heavens. 
 I confess it is impossible to contemplate all this without a 
 feeling of awe. 
 
 Would that the mystery of the comet were once unfolded 
 to us ! It tantalizes us by its near approach and its undimin- 
 ished inscrutableness. But, thanks to intelligence thanks to 
 the spirit of science thanks to that beneficent constitution of 
 the universe by which it gives up its secrets one by one, to 
 the demands of intelligent inquiry, we have found out some- 
 thing. We have seen comets torn to pieces by the power of 
 attraction without a collision by the attractions of the sat- 
 ellites of Jupiter. This was Bi-e'-la's [Be-a'la] comet, and 
 each fragment thenceforward pursued its separate path. We 
 have seen comets so shattered and disintegrated by the pulls 
 and strains to which they were subjected in our system in 
 making their circuit about our sun, in getting through the en- 
 tanglements of Jupiter's and Saturn's attractions, that they 
 appeared literally to be going to pieces and dividing up their 
 remains among the planetary masses of the system. 
 
 The comet, in short, appears to be essentially a train of 
 stones flying with three thousand times the velocity of the 
 railroad " express." The smaller stones more resisted than the 
 larger ones, by other matter disseminated through space, 
 slacken their motion slightly, and are struck by the larger 
 
 18 
 
210 WALKS AND TALKS. 
 
 stones with velocities exceeding that of a cannon ball. Light 
 is disengaged, as when the cannon ball strikes the iron target ; 
 and thus the whole cometary train is lighted up. The nearer 
 it approaches the powerfully attractive bodies of our system, 
 the greater these disturbances become the intenser the lumi- 
 nosity the more extended and the more widened the train of 
 finer materials. But do not think this train of stones is the so- 
 called luminous "tail" of the comet. The tail always turns 
 away from the sun ; the dark train follows in the path of the 
 comet. The cause of the tail is yet a mystery. It may be a 
 smoke of luminous particles driven off by the intense heat of 
 the sun. 
 
 The comets all have to make a journey around the sun. 
 Some of them remain in our system and subject themselves to 
 the laws of the planetary family; but others can not be in- 
 duced to stay ; they rush onward with such velocity that all 
 the power of the sun and planets is not sufficient to stop them. 
 They launch out from our remotest shore, on the limitless 
 ocean of space which stretches to the shores of other systems, 
 and stretches beyond, farther than imagination can picture. 
 But the comet which becomes domiciled in our system seems 
 gradually to undergo disintegration, and by and by its borders 
 are spread so far as to brush the atmosphere of some planet 
 when passing near it. Our atmosphere has been thus pierced 
 by the outlying constituents of certain cometary trains. 
 Sometimes countless thousands of them shoot through the air. 
 These missiles move with a velocity as high as twenty to forty 
 miles a second, and the friction and condensation resulting 
 develop sufficient heat to render the missile luminous. 
 
 We call it a meteor. We had not contemplated the meteor 
 as a burning fragment of an old decayed comet. But some of 
 our most splendid meteoric displays have resulted from clouds of 
 meteoroidal bodies which have been quite certainly identified 
 with recognized comets. At certain regular intervals, on or 
 about the sixteenth of November, occurs a celebrated meteoric 
 shower which comes from a meteoroidal train or cloud that 
 has been identified with Tempel's comet the first one observed 
 
GATHERING WORLD STUFF. 211 
 
 in 1866. Another meteoric shower occurring annually about 
 the tenth of August has been identified with the third comet 
 of 1862. Also, the shower which occurs on the twenty-seventh 
 of November, and was particularly conspicuous in 1885, has 
 been connected with Biela's comet, first observed in 1826. 
 This is the comet which was parted. The fragments have not 
 appeared to view during several revolutions; and there is 
 reason to think nothing remains but dark trains of stones. 
 
 So much is pretty well settled. There are numerous other 
 trains of meteoroidal matters which we have reason to regard 
 as worn out comets. In fact, since we have meteoric displays 
 on nearly every night of the year, must there not be as many 
 meteoroidal trains as there are distinct radiant points from 
 which the meteors shoot ? One train, you understand, might 
 touch our atmosphere on one side and another on a different 
 side. To our eyes, the motions of the ignited meteors would 
 be in all directions from the region of contact. That region 
 would be projected on some constellation, and would remain 
 fixed there though the earth rotated. So each radiant point 
 would imply a different contact a different swarm ; and ac- 
 cordingly there must be a hundred swarms or more which 
 touch our atmosphere. 
 
 But reflect now, that a meteoroidal swarm is describing an 
 orbit about the sun, and we learn of its existence simply be- 
 cause it happens to pass very near the orbit of the earth, and 
 happens to pass at the time when the earth is there. If it 
 passed at a little greater distance, or passed always when the 
 earth was absent, we should know nothing of the swarm save 
 possibly as a comet, if not yet too much disintegrated to emit 
 light. How many chances against this favorable concurrence 
 of positions ! How many more swarms there must be which 
 never reveal to us their existence ! When we reflect that we 
 are brushed by say a hundred of them annually, must we not 
 conclude that there are thousands which sweep through space 
 unnoticed? I think the spaces around us must be full of 
 their motions. Were our vision perfect, we should see the 
 heavens clouded by swarming meteoroids darting in every con- 
 
212 WALKS AND TALKS. 
 
 ceivable direction like the clouds of home-returning swallows 
 in the dusk of a summer evening. These particles of cos- 
 mical matters these clouds of cosmic dust intervene between 
 us and the sun, and must shut out a large proportion of the 
 solar light and heat. We are told by Professor J. P. 
 Langley that not more than half the sun's radiant force reaches 
 the earth. They tell us the remainder is "absorbed" by the 
 atmosphere and the dust which floats there ; but much of the 
 absorption must be accomplished by the cosmic matter which 
 exists beyond the atmosphere. The absorption thus effected 
 would be still greater to the inhabitants of Venus and Mer- 
 cury, if inhabited ; since cosmic matter must be more accumu- 
 lated in the nearer neighborhood of the sun. Thus the tem- 
 perature on those planets would be lower than their proximity 
 to the sun would lead us to suppose. On the same principle, 
 the solar emanations at Mars or Saturn would be greater than 
 their distances from the sun would lead us to suppose. Who 
 can tell how far these adaptations may go in compensating to 
 other planets for losses due to different distances from the sun ? 
 
 We have seen the meteor ignited in the upper air. We 
 have seen its bright streak vanish while we gazed. The little 
 body was melted it was vaporized. While passing through 
 the space measured by its line, it changed from a cold stone 
 to shining dust, and then a darkened dust left floating in the 
 upper strata of the atmosphere. But though unseen, the me- 
 teoric dust still exists. It now belongs to the earth. It will 
 be wafted to and fro by the winds ; it will come down, after 
 some months, and contribute some new material to the earth. 
 Some of these atoms will fall on the ocean ; most of them 
 will fall there ; and after other months they will settle to the 
 bottom and mingle with the ooze which is there accumulating. 
 You will remember our walk under the sea (Talk X), and the 
 comet-dust which we found. It is an impressive thought. 
 This black particle now resting through an eternity on the 
 midnight-shrouded ocean-bed, shone lately in a star. There 
 are greater changes of fortune than any suffered by us. 
 
 The point which we have reached reveals the boundless 
 
GATHERING WORLD STUFF. 213 
 
 space around us well stocked with material particles. They 
 are not uniformly distributed; by their mutual attractions 
 they are gathered into swarms. The swarms are not motion- 
 less ; they are drawn toward every attracting body in the uni- 
 verse. They are not changeless; by degrees each swarm 
 grows as long as it has a separate existence, by the accession 
 of other swarms. As these swarms sail majestically through 
 the ocean of immensity, some are brought under the control 
 of distant suns, and start on long journeys to pay their flying 
 visits. They approach now as comets. If they are induced 
 to circle perpetually about given suns, they finally go to 
 pieces again, and the parts are either drawn to their central 
 suns, or distributed among the planets. If they escape from 
 the systems entered, they steady themselves across the gulfs of 
 space which separate systems, and in the progress of centuries, 
 float into other ports and new excitements. 
 
 But some of these swarms remain floating in the depths of 
 extra-firmamental space, and gather to themselves, by their 
 increasing power of attraction, all other swarms and particles 
 from their region of immensity. They become Nebvlce. They 
 are luminous because pounded by the fall of other swarms, 
 and lighted by the collisions of their internal parts. They 
 are composed of matters solid, liquid, and gaseous. They 
 rotate. Poised in space, the impacts of gathering matters 
 have started them on their axes of motion. There they are 
 before our eyes. The background of the heavens is phos- 
 phorescent with the glow of these distant fields of world-stuff. 
 Each is a living picture of that primordial state in which we 
 fancy the matter of the solar system existed when that his- 
 tory of cooling began which we endeavored to trace to a 
 starting point. 
 
214 WALKS AND TALKS. 
 
 NEBULAR THEORY OP WORLD ORIGIN. 
 
 BEHOLD the matter of a solar system in the form of a 
 nebula. Poised in the midst of space, it tends to a globular 
 form ; but the attraction of its own center is so distant as to 
 be feebly felt at the remote periphery of so tenuous a mass. 
 The late accessions of nebulous stuff have left superficial irreg- 
 ularities like those in the clouds which float in our atmos- 
 phere. They subside with comparative slowness; but yet they 
 tend to disappear. This vast empire of world-stuff rotates, 
 but a million of years may flee away before one revolution is 
 completed. With eternity at command all finite intervals of 
 time are zero. I can not answer the question whether a gas- 
 eous constitution pervaded all parts of this nebula. I think 
 it probable that portions of the included space were filled with 
 gas. I think such portions may have been bounded by the 
 sphere on which the elasticity of the gas was equalized by oppos- 
 ing attractions. There was already fire-mist fine liquid par- 
 ticles suspended in gases or poised between counter attractions. 
 There were probably stones and concretions of iron hanging 
 suspended through the mass. It is not at all supposable that the 
 entire space within the periphery of the nebula was occupied. 
 There may have been spaces hundreds or thousands of miles 
 wide, not filled with any thing but the all-pervasive ether if 
 that exists. I do not conceive a continuous medium so unim- 
 aginably thin as would result from the expansion of the mat- 
 ter of the solar system uniformly through a sphere bounded 
 by the orbit of Neptune. 
 
 If this mass is heated, it radiates heat into surrounding 
 space, and the heated parts contract. If the parts are still 
 gathering themselves nearer to the distant center of gravity, the 
 whole mass contracts. If the time ever arrives when the 
 parts gathering toward the center of gravity are balanced by 
 mutual resistances, or by reaction of heat, then further loss 
 of heat will result in contraction of the whole mass. In 
 either event, the mass contracts. If a rotating body contracts, 
 
THE WHIRLING FIRE MIST. 215 
 
 its rate of rotation is accelerated. This is one of the neces- 
 sary laws of matter. A rotating sphere of tenuous matter 
 undergoes some flattening at the poles ; as the velocity of rota- 
 tion increases, the polar flattening increases; the equatorial 
 protuberance increases. The earth is equatorially protuberant 
 because it rotates. 
 
 When a body rotates on its axis, the parts around the 
 equator experience a tendency to fly off, which is greater than 
 such tendency on other parts of the surface. A rapidly rotat- 
 ing grindstone throws off the water. An emery wheel rotating 
 too rapidly for its strength flies asunder, in consequence of 
 excess of the flying-off or centrifugal tendency. The centrif- 
 ugal tendency is stronger than the cohesion of the parts. If 
 the earth were to rotate seventeen times as rapidly as it does, 
 bodies at the equator would have no weight. In the rotating 
 nebula which we are considering, the centrifugal tendency of 
 the equatorial parts diminishes their weight, and the undimin- 
 ished weight of the polar parts presses the equatorial out 
 in a bulge. 
 
 Meantime the nebula contracts and the rate of rotation 
 continues to be accelerated. What must result under this 
 tendency of things? Evidently the time will arrive when 
 parts on the equator will have acquired a tendency to fly off 
 just equal to the attraction by which they had been held in 
 their places. If contraction still continues, as it must in a 
 cooling mass, the peripheral parts, balanced between equal 
 centrifugal and centripetal forces, will not move either toward 
 the center or from the center. What should make them? 
 Those parts will remain where they are, and the parts within 
 will withdraw from the equatorial parts. That is, a ring will 
 be disengaged not thrown off. The ring will retain the rota- 
 tion which it had, and the residual mass will continue to cool 
 and accelerate its rotation within the ring. 
 
 What will happen to the ring? Perhaps you have seen 
 the ring of white smoke resulting from the explosion of a soap 
 bubble inflated with phosphureted hydrogen ; what happened 
 to that? It floated as a ring till external disturbances caused 
 
216 WALKS AND TALKS. 
 
 its rupture, when the smoke became a simple cloud. The 
 cosmic ring will experience the same fate. This nebula is 
 not hanging in the universe alone. All sjsace is animated by 
 moving masses and groups of masses. Comets are darting to 
 and fro. Distant suns are tugging steadily, even if feebly, 
 on the parts of this ring. Somehow, in 'the course of ages, 
 the balance of the ring will be destroyed. An excess of mat- 
 ter will be drawn to one side ; and, as a consequence, all the 
 matter will be drawn to that side. Or, perchance, the unequal 
 attraction may set up a wabbling rotation of the ring. Then, 
 by the laws of matter, the wabbling will increase until the 
 ring is ruptured. That will cause all the matter to gather to 
 the unbroken side. 
 
 Thus, from one cause or another, the ring of nebulous 
 matter must become a sphere of nebulous matter. Its distance 
 from the original center is the distance of the ring. This 
 sphere moves in an orbit occupying nearly the place of the 
 ring. This sphere rotates on an axis, and the direction of the 
 rotation will be determined largely by the width of the ring 
 from which it was formed, and relative velocities of the outer 
 and inner circumferences of the ring. In this place I can 
 not attempt to explain this matter. Suffice it to know that 
 in most cases, the direction of the rotation would be the same 
 as the direction of the mass in its orbit; but if the diameter 
 of the orbit is relatively very great, the direction of rotation 
 may be the reverse of the motion in the orbit. 
 
 This resultant spheroid is to become a planet. The resi- 
 dual mass continues its history as begun. By and by, another 
 ring is detached, and in the course of ages, this also becomes 
 a spheroid destined to become another planet. Meantime, as 
 the disengagement of a new ring diminishes the mass of the 
 central body, the centripetal force exerted on the first planet 
 is diminished. The centrifugal force therefore increases its 
 distance from the common center. This diminishes its angular 
 velocity, and therefore the centrifugal force, and thus the 
 centripetal and centrifugal forces become equal again both 
 diminished. 
 
THE WHIRLING FIRE-MIST. 217 
 
 Thus two planetary masses come into existence. By repe- 
 titions of the same process, a complete series of planetary 
 masses becomes scattered over the distance between the 
 original periphery and the center ; and at each occasion of 
 planetary birth, all the older planets recede a certain distance 
 farther from the center, and undergo a certain retardation in 
 their orbital velocities. The different planetary masses, how- 
 ever, do not possess equal densities ; they are not composed of 
 such ingredients as to furnish, on cooling to a given temper- 
 ature, the same proportion of solid, liquid, and gaseous con- 
 stituents. Before planet making began, we may suppose the 
 heavier constituents of the general mass had gravitated to the 
 central regions ; while the lighter constituents remained 
 nearer the periphery. If so, the first planets separated would 
 contain more of the substances which, at temperatures familiar 
 to us, make gases and water. Similarly, the later planets 
 disengaged would acquire a larger proportion of the sub- 
 stances which form solid rocks. In the case of the earth we 
 may suppose the greater part was rock-making material, since 
 the earth's specific gravity is so high ; but watery stuff in 
 sufficient amount to provide oceans and rains, went off with 
 the rock material, and with these, the lighter stuff for an 
 atmosphere. But in the case of Venus, most of the stuff was 
 rock-material, if not the whole of it ; while with Mercury it 
 seems probable that little water-stuff was included. In the 
 opposite direction, Saturn, Uranus, and Neptune must have 
 received a large excess of water and atmospheric stuff. It is 
 rational to suppose that their oceans have always covered the 
 whole land, as ours does more than half. In fact, these bodies 
 must be composed chiefly of water and atmosphere ; as their 
 specific gravities are low as water and cork. 
 
 So, in the history of our system, the work went on as 
 long as the conditions existing permitted the central mass to 
 detach rings. Meanwhile, the planetary masses entered sev- 
 erally on their separate careers. Each career was, in effect, 
 a history of cooling. They did not proceed with equal pace, 
 since some, with larger mass than others, had more heat to 
 
218 WALKS AND TALKS. 
 
 radiate, and the power to radiate was not in proportion to the 
 mass but to the surface. Hence, some of the older planets 
 are less advanced than the earth, because so much larger ; 
 while Mars, I imagine, is more advanced, both because smaller 
 in mass and older. Now, during the habitable stage of 
 the earth, the sun remains the residual mass of the ancient 
 nebula. 
 
 The sun is a relic of the primordial fire-mist. The sun is 
 historian of a mighty past. He is more to us than a source 
 of bodily comfort. He has shed his vivifying warmth on all 
 the populations which have appeared and disappeared in the 
 history of terrestrial life. He stimulates to growth during 
 the human age, the crops which supply our food, and affords 
 the warmth which yields us comfort and maintains the activ- 
 ities of the natural world. But the sun is more to us than 
 this. He sustains relations to our intelligence. He proclaims 
 and exemplifies our material origin. He responds to our 
 anxious inquiry concerning long histories which were enacted 
 in the ages unnumbered; before man existed. 
 
 The history of each planetary mass has repeated the 
 history of the general mass, as far as physical conditions per- 
 mitted. The planetary mass was a fire-mist possessing r;ady 
 mobility of pajts. It rotated, cooled, contracted, and under- 
 went acceleration of rotation. The larger masses retained the 
 fire-mist state sufficiently long to detach several rings. From 
 these originated the satellites of the larger planets. The 
 earth underwent but one annulation, and had then assumed 
 the fluid or molten state. The two interior planets, with a 
 larger proportion of fixed constituents, attained a fluid state 
 before sufficient contraction had been experienced to lead to 
 the evolution of a single satellite. 
 
THE PRIMEVAL STORM. 219 
 
 XXXVIII. THE PRIMEVAL STORM. 
 
 ORIGIN OF THE OCEAN. 
 
 LET us DOW attempt to trace the physical history of that 
 planetary mass which was destined to become the earth. We 
 contemplate it in a state of fire-mist. Here are no water, no 
 atmosphere, no rocks, no organic forms. In this fire-mist, 
 however, were the elements of all the forms of matter which 
 were to exist in or upon the earth, in the long progress of its 
 history. Here were the calcium and the oxygen and the car- 
 bon which molluscan life would appropriate for its shelly cov- 
 erings. Here was the stuff which, long ages after, was des- 
 tined to swim as a fish in the wide ocean. Here were the 
 ultimate elements which were to grow in forests or wave in 
 tinted sea- weeds. Here was the matter which, in the course 
 of time, would be organized in human bodies the solid bones 
 were there, the graceful contours of the flesh, and the crimson 
 life-blood destined to glow in the maiden's cheek. Only Infi- 
 nite Mind could embody in one plan, things so contrasted and 
 so remote in time. 
 
 The moon, on what seems to me the most probable view, 
 had already been separated, but was still much nearer the 
 earth than at present, and performed its revolution in a shorter 
 period. The earth's axial rotation was correspondingly more 
 rapid.- Earth and moon mutually exerted powerful tidal 
 actions (see also Talk XX). Each changed the form of the 
 other from the simple oblate spheroid shaped by rotation, to a 
 prolate modification of this. That is, each by its attraction 
 drew the other into a form slightly elongated. The elonga- 
 tion was a " deformative tide" or "bodily tide." Of course, 
 the moon was much more deformed than the earth. The tidal 
 elevation on the moon, at its present distance, is one hundred 
 and thirty-four times that on the earth. Those tidal inter- 
 actions have always existed, and still exist. 
 
 I can not affirm that the matter of the earth was now all 
 fire-mist suspended in a continuous gas. There must always 
 
220 WALKS AND TALKS. 
 
 have been, since fire-mist first began to form, a tendency of 
 the liquid particles to coalesce, and this tendency would in- 
 crease with the progress of cooling. A time would arrive 
 when drops thus formed would begin to descend by gravity 
 toward the center of the fire-mist sphere. They are not to be 
 conceived as dropping with accelerated velocity, like bodies 
 falling through space, since within the sphere, the central 
 attraction continually diminishes as the distance from the 
 center diminishes. At the center the attraction is equal in all 
 directions. But the molten liquid began finally to accumu- 
 late at the center. It shaped itself in a globe which grew as 
 the fiery precipitation continued. In the course of time, the 
 greater part of the fire-mist had rained down, and a molten 
 earth stood forth in space, glowing with a white heat, and 
 enveloped in a hot and heterogeneous atmosphere which con- 
 tained all the substances vaporized at the temperature then 
 existing. 
 
 This self-luminous earth was a sun in reference to the 
 moon. The moon had already advanced to a stage corre- 
 sponding with that called habitable, and the light afforded its 
 conceivable inhabitants was twelve times as intense as that re- 
 ceived from the sun assuming the distances the same as at 
 present. The earth was a star, and had long been a star, to 
 the inhabitants, if any, of remote orbs. Perhaps they had 
 descried it with their instruments ; perhaps it had been noted 
 in their catalogues, with latitude and longitude thus and so. 
 The sun was now shedding its superfluous light and heat on a 
 planet which was yet itself a sun. 
 
 The molten earth continued to waste its heat. The ex- 
 posed surface materials, as fast as chilled, sank into the in- 
 terior by their superior density, and hotter materials rose to 
 the surface. There was a circulation between the surface and 
 interior. This prevented any extreme difference in tempera- 
 ture. But some greater reduction was always experienced at 
 the surface. It was at the surface, therefore, that the first 
 solidification took place. At this juncture, the sinking of the 
 coolest portions ceased. Rock-materials, like all others which 
 
THE PRIMEVAL STORM. 221 
 
 crystallize on solidifying, undergo a slight enlargement in the 
 act of becoming solid. A crust, therefore, began to form over 
 the liquid planet. Like ice on the lake, it floated. If you 
 go to the crater of Kil-au-e'-a, in Hawaii, you will find a vast 
 lake of molten rock, the surface of which has frozen into a 
 crust like that which formed over the earth's surface. There 
 is no mistake in the opinion that the cooling crust would 
 float. 
 
 The tidal protuberance caused by the moon never ceased. 
 The side toward the moon was always uplifted. As the earth 
 turned on its axis, a different part of the terrestrial surface 
 was raised at each moment. The great tidal swell swept past 
 every point of the surface at every revolution of the planet. 
 Thus the forming crust was alternately uplifted and depressed. 
 Much fracturing of the crust must have resulted. The crush- 
 ing and grinding of the fragments displaced them; great 
 lateral pressures tilted them on edge and piled them up in 
 enormous hummocks. The scene must have been analogous 
 to those in Baffin's Bay and the Arctic Ocean, of which ex- 
 plorers bring us exciting accounts. The surface of the earth 
 assumed the rugged character of a vast " floe." 
 
 I imagine this floe was still luminous, except in the pro- 
 jecting crags. Over this still glowing terrestrial surface, sun- 
 light was still shed. Who can calculate the length of the 
 aeons which passed while such a scene of desolation reigned? 
 It was, indeed, destined to reach its end; but only through 
 the transformation of an age of terrific violence. All the 
 time, the process of cooling went forward. While the white- 
 hot crust subsided to a red-hot temperature, the atmosphere 
 became less parched. While the shadows of a darkening crust 
 tipped the most salient crags, the upper air grew continually 
 freer from the terrific heat which had swept outward from the 
 terrestrial surface. As the temperature of the air subsided, 
 there were precipitations of various substances which could 
 maintain their gaseous condition no longer. At length it 
 came the turn of water to begin to condense. It had long, 
 already existed as an invisible gas. Now, with an upper air 
 
222 WALKS AND TALKS. 
 
 temperature passing below 212, the invisible steam began to 
 become visible vapor. 
 
 This was a grand juncture in the history of the world. I 
 have often pictured it. I have often wished I might have be- 
 held the scene. I think, could I have been present, I should 
 have witnessed something like this: The forming vapor in 
 the upper air reveals its presence in a thin and gauzy haze, 
 like that which overspread the sky when the ashes of Kra- 
 kat'-o-a were floated round the world. The veil grows thicker 
 from age to age. It is now a * ' cirrus " sheet of cloudy vapor 
 like that which the anti-trades drive up from our south- 
 western horizon. The contour of the round sun is blurred ; 
 the intensity of his ancient ray is softened. Indeed, his light 
 is dimmed; the haze is becoming a cloud. A twilight ap- 
 proaches; the shade deepens. The world is enveloped in a 
 cloudy pall ; the lurid light of the decaying fires of the crust 
 reddens the overarching canopy. The sun is quenched ; the 
 world hangs in shadow which forms the first night which 
 ever visited its surface. " In the beginning " there was " light ;" 
 now "darkness is upon the face of the deep," and a denser 
 darkness impends. 
 
 The burdened clouds drop rain. The o'erburdened clouds 
 discharge a storm of rain. The drops descend into the lower 
 and heated strata of the atmosphere, and are dissipated 
 into vapor which rises to the clouds to be again condensed. 
 Continual rains descend ; but the hot air dries them up and 
 sends them back to the bosom of the clouds. There is a bat- 
 tle in mid-air between the powers of water marshaled above, 
 and the powers of heat intrenched behind the rocky ramparts 
 below. I think of the battle over the Catalaunian plains, 
 waged at night, in rn id-air between the spirits of the slain 
 Romans and those of the hordes of Attila. But the powers 
 of water are destined to prevail. The forces of fire are per- 
 petually carried captive with returning vapors, and retired be- 
 yond the ranks of the clouds. 
 
 Meantime the equilibrium of the electricities is disturbed. 
 The friction of ascending vapors and descending rains develops 
 
THE PRIMEVAL STORM. 223 
 
 electrical phenomena as in the bosom of the summer-cloud 
 which rising vapors swell into a threatening monster that 
 rears its "thunder-head" above our western horizon. Here, 
 in this storm of the ages, the dazzling glare of ten thousand 
 lightning gleams sheds an infernal tinge over the murky world ; 
 and the responsive voices of ten thousand thunders split the 
 welkin with their detonations. While this fury and chaos reign, 
 the line of battle sinks to the hot surface of the earth, and all 
 at once the attacking waters are volatilized in ten thousand 
 explosions, which rend the elements. Imagination, even, 
 shrinks from the contemplation of the scene. 
 
 But we must brave the struggle through ; the culmination 
 of the great seonic storm is passed. The powers of fire are 
 vanquished ; the waters gather over the heated crust. They 
 are furious with effervescence and ebullition, but they hold 
 possession. On all sides rise columns of steam from a boiling 
 ocean. The atmosphere, once so arid, is now soaked with 
 vapor. The skies still drip with rains, but the gloom is not 
 so dense. There seems to be a day-break on the scene. The 
 exhaustion of the clouds proceeds ; and now behold, it is dawn. 
 A new cosmic day is rising on the flooded world. The volume 
 of the ocean swells ; it has no shore. The clouds, fed by the 
 vapors of a heated ocean are not dispersed ; but a brightening 
 glow heralds promises of a new age. The years speed on, and 
 the alternations of night and day are discernible. The years 
 speed on, and expectation waits for some glorious denoue- 
 ment. Behold, it arrives. The sun in his daily circuit 
 about the world so long lost to him, rose one day in the east- 
 ern sky, and a broad rift in the clouds let in a golden beam 
 of sunlight, direct upon the waters which enwrapped the earth. 
 
 How changed the scene since last those rays fell useless on 
 the scorched and glowing crust. Then the self-luminous earlh 
 cast no shadow, and there was no night. Now, one hemi- 
 sphere is in darkness and the other is in sunlight. Now for 
 the first time, as the earth rolls on its axis, the succession of 
 night and day becomes possible. Now, for the first time, the 
 sun becomes "the ruler of the day" and the moon of the 
 
224 WALKS AND TALKS. 
 
 night. Do not say this is all a dramatic representation. How 
 else could the forces work? It is reasoning, not imagination 
 which has reproduced the incidents of the primeval storm. 
 That storm was a real chapter in the childhood history of the 
 planet which is our home. So we must remember it. But, 
 thanks to the constitution of nature, we live in the fortunate 
 period when, on another member of our planetary family, the 
 secular storm is raging. From our safe distance we hear none 
 of the turmoil which reigns on Jupiter ; but we can gaze on 
 the exterior of the cloudy envelope, and we can believe our- 
 selves, with Lockyer, catching glimpses, at times, of the light- 
 ning flashes which glare within, and seem to shoot their darts 
 quite through the blanket of vapors. A specimen world still 
 in its swaddling clothes held back in development, that our 
 human intelligence might find response to its earnest inquiries 
 about the past held back, like the living rings of Saturn, to 
 serve as samples of unformed worlds, hung up to illustrate the 
 divine process of world formation. 
 
 XXXIX. THE \VAR IN THE OCEAN. 
 
 THE EARLIEST STRATA. 
 
 A SHORELESS ocean now enwrapped the world. It was not 
 a placid summer expanse overhung by bright skies and swarm- 
 ing with happy sentient creatures. The rains which supplied 
 the ocean had washed from the atmosphere certain acid gases- 
 especially sulphuric, chlorhydric, and carbonic and these 
 pervaded the water now resting over the earth. The fire- 
 formed crust, however, on which the ocean rested, was com- 
 posed chiefly of silicates of somewhat complex constitution, 
 but largely silicates of alumina, potash, soda, lime, and mag- 
 nesia. Now, when the hot acid waters came in contact with 
 these silicates, certain reactions immediately began. The 
 silicates were decomposed; the alkaline bases, potash, lime, 
 and so forth, were taken up by the free acids, forming chlo- 
 rides of potassium, calcium, sodium, magnesium; as also 
 sulphates and carbonates of potash, soda, magnesia, and lime. 
 
THE WAR IN THE OCEAN. 225 
 
 Now some of these resulting compounds were soluble, and 
 remained dissolved in the sea-water. Such were the chlorides 
 and sulphates, and the carbonates of potash and soda. Thus 
 the water of the primitive ocean became charged with 
 sulphate of soda, which is Glauber's salt; sulphate of 
 lime, which is gypsum ; sulphate of magnesia, which is 
 Epsom salts; also with chloride of sodium, which is common 
 salt ; and the other chlorides, which are the bitter impurities 
 in the sea. 
 
 But others of the resulting compounds were but little 
 soluble, and were therefore precipitated to the bottom; what were 
 they? Carbonate of lime and carbonate of magnesia. The 
 first is limestone, and the second is generally mixed with the 
 first, forming dolomite. That is, a layer of calcareous material 
 was spread over the sea-bottom. It was a chemical precipitate, 
 not a sediment in the geological sense. Two other constituents 
 were added to the material spread over the bottom. I stated 
 above that the primitive crust contained silica and alumina ; 
 what became of these when the original partners had to sunder 
 connections? Potash, soda, lime, magnesia we have traced to 
 their destinations ; but silica and alumina are left outstanding. 
 Now, probably, these concluded to form a partnership for 
 themselves ; and so silicate of alumina resulted. This being 
 insoluble, must have fallen to the bottom. It may have 
 mingled, in some places, with the calcareous precipitates and 
 it may in other places have been bedded by itself. In the 
 latter case, beds of argillite would result. With the silica and 
 alumina some potash may in other cases, have combined ; and 
 thus would be formed a mineral known as potash feldspar , or 
 common feldspar. If soda or lime, instead of potash, united 
 with the silica and alumina, the result was simply another 
 species of feldspar. The feldspars are very abundant in the 
 oldest rocks. 
 
 But perhaps, again, some of the outstanding silica and 
 alumina concluded not to combine together. Then the alumina 
 would simply remain free alumina, to mix with any of the 
 other compounds produced, or form by itself a bed of pure 
 
226 WALKS AND TALKS. 
 
 clay; and the silica would, in a similar way, mix with other 
 substances or form by itself beds of pure quartz. 
 
 If these views are correct, it appears that the mineral con- 
 stituents of sea-water date from the primeval time. The table 
 salt so familiar to our senses is a venerable product. The 
 sodium had endured the heat of the molten globe and consoli- 
 dated as a silicate in the first crust. The chlorine had drifted 
 about, a constituent of the heterogeneous atmosphere, until 
 the war of the elements came ; when it was dragged down as 
 an incident of the conflict. Here it found occasion for un- 
 wonted activity ; and all over the world, chlorine atoms busied 
 themselves in soliciting sodium atoms, to gratify a newly dis- 
 covered liking, and create, in unlimited abundance, a sub- 
 stance destined to acquire unlimited usefulness. So our 
 common salt, which knows so well how to grow old unchanged, 
 is employed by us to assist other substances to grow old 
 unchanged. 
 
 We may inspect, now, the oldest rocks accessible to inves- 
 tigation, and see if they are the kinds which should be 
 expected, according to the above reasoning. Yes, in a general 
 way they are. Feldspars are everywhere disseminated in the 
 bottom rocks. There are great beds of crystalline limestone, 
 and of argillites. There are micas, hornblende, and augite, 
 all of which, like the feldspars, are essentially silicates of 
 alumina and other bases. But here, also, are conglomerates, 
 composed of rounded or angular fragments of older rocks. 
 Here, indeed, are vast formations of quartzites, but they are 
 formed of grains, instead of being those purely vitreous masses 
 which would result from the precipitation of free silica. But 
 each separate grain is such vitreous quartz, and it appears as 
 a fragment of some rock in which the whole mass was purely 
 vitreous. At some time then, earlier than the formation of 
 these granular quartzites there were formed quartzites not com- 
 posed of grains, but continuous like a mass of glass. We 
 have to conclude that the oldest rocks accessible are not rem- 
 nants of the primeval precipitates. This is the conclusion 
 pointed out also by the presence of conglomerates. 
 
THE WAR IN THE OCEAN. 227 
 
 Let us trace further the necessary succession of events. 
 The chemical war is now settled by treaty of peace ; but the 
 rains of a geologic spring-time are still frequent and copious. 
 The tides and waves stir up the fine particles resting on the 
 bottom, and these float off' to the deeper situations, where 
 they subside as sediments fragmerital sediments. This con- 
 sequence of unequal depth in different parts of the shallow 
 ocean is augmented in course of time, by the formation of 
 wrinkles in the crust. These resulted, as explained in Talk 
 XX, from the lateral pressure due to the contraction of the 
 eartk within the crust. This was an incident of. cooling. 
 The wrinkles did not, at first, rise above the surface of the sea ; 
 but they formed bars and shallows, while between them were 
 the depths. Over these bars the tides and waves stirred up 
 sediments which settled in the deeper water not far remote. 
 
 I find no improbability in the supposition that plant life 
 was now in existence. The fronds of fucoids could be rooted 
 on bottoms within reach of the aerating agency of the atmos- 
 phere ; and though full sunlight was not yet revealed ; there 
 was a twilight sufficient to meet the requirements of the hum- 
 blest forms of vegetal life. Whence this life originated, 
 science is unable to declare. Yesterday there was no life yet, 
 on all the planet. To-day it is here positive organic life. 
 In the night a sower came and unobserved, strewed the beds 
 of ocean with germs which came to earth as a free gift ; and 
 now the world possesses a new capacity a new starting 
 point a new potency. From this datum, a limitless field of 
 speculation spreads out, which many a thinker has explored 
 in which many a thinker has been lost. The inductive evi- 
 dences supporting this deduction are found in the beds of 
 graphite included in the older rocks, though I do not imagine 
 these to have been formed till many ages after the first advent 
 of marine plants. 
 
 The time arrived when some of the ever-growing wrinkles 
 rose dripping above the ocean level. They were not, to any 
 great extent, domes and ridges of granite and granitic rocks. 
 They were arches of the primeval fire-formed crust. The 
 
228 WALKS AND TALKS. 
 
 mineral constituents of granitoid rocks had indeed been 
 formed as already stated quartz, feldspar, mica hornblende, 
 augite and they probably overspread these upheavals but I 
 believe these minerals must have existed under different as- 
 pects, and I think the minerals which compose the granitoid 
 rocks have resulted from metamorphism of plain sediments, 
 as I shall explain. We can not, therefore, look upon our oldest 
 "granite domes" as examples of the earliest crust, nor of the 
 earliest precipitated beds. They are later. Let us see. 
 
 There were long, low ridges of barren rock now emergent. 
 I can not state where they lay ; but it seems probable they oc- 
 cupied nearly the places of later ridges which were to rise as 
 the germs of the continents. Old ocean now seemed envious 
 of his loss, for he immediately began pounding and devouring 
 the slender land, and taking it back into his possession. The 
 work of erosion was inaugurated, from which old ocean has never 
 desisted to this day. Nothing escaped from his domain with- 
 out a conflict ; and many a patch of land and many a conti- 
 nent has thus been reclaimed for his possession, as we 
 shall see. 
 
 I wish to emphasize here a doctrine which has been very 
 generally overlooked. Ocean sedimentation has been carried 
 on only around the continental slopes. The products of ero- 
 sion have been laid down in waters comparatively shallow, 
 and not in the distant abysses of the ocean. The deep remote 
 sea-bottom remains to our times, with only a shallow covering 
 over the primitive crust. In our walk under the sea, we 
 found no continental sediments in the deep sea. We found 
 there a state of changelessness and stagnation. We found no 
 evidence of fragmental rocks. We found, on the contrary, 
 in the abyssal islands, rocks of igneous origin samples of the 
 old fire-formed crust, as I suspect. 
 
 The accumulation of sediments over any portion of the 
 ocean's bed would constitute a thickening of the crust. But 
 the thickness of the crust was already adjusted to the intensity 
 of the heat within. It was of such thickness that the heat 
 within could not escape with rapidity sufficient to melt the 
 
THE WAR IN THE OCEAN 229 
 
 lower surface, and thin the crust. It was of such thinness 
 that the internal heat escaped with rapidity sufficient to pre- 
 vent a lowering of the temperature of the different zones of 
 crust, and thus produce a thickening of the crust. But, if 
 by sedimentation, the crust were made thicker, this balance 
 would be destroyed ; the escape of internal heat would fye re- 
 tarded, and it would therefore, re-fuse the inner surface of the 
 crust, and restore the thickness, and with it, the balance of 
 actions. Thus, wherever the original crust has been supple- 
 mented by sediments, more or less of the original crust has 
 been lost from the under side. Who can say how much has 
 been lost? Undoubtedly, an amount approximating the entire 
 thickness of the overlying sediments. It is generally admitted 
 that the Eozoic strata are 50,000 feet thick. There must 
 have been consequently, 50,000 feet of the primitive crust 
 melted away. This leaves crust-thickening due to progressive 
 cooling, to be supplied by sediments above the Eozoic. If 
 the Eozoic beds extend down 30 miles, then 30 miles of 
 primitive crust are lost. If that crust was less than 30 miles 
 thick, then some part of the 30 miles melted away must have 
 been sedimentary rocks. 
 
 I wish to make one more point in this connection, and 
 that, I believe is new. If sediments accumulated only along 
 the continental slopes, then not only did all formations grow 
 finer and thinner in receding from the shore ; but they must 
 be found to disappear at great distances from the shore ex- 
 cept in shallow water. Thus, we are not at liberty to suppose 
 the Eozoic beds extended under all the oceans, so as to be 
 literally universal. Wherever they now exist, the land was 
 then not far distant. Thus also, in general, it should result 
 that all formations grow thinner and less fragmental as they pass 
 under newer formations. 
 
 So it appears that by due reflection, it becomes possible to 
 reproduce the important features of the ocean's primitive his- 
 tory. The earliest outcrops of sea-bottom were entirely con- 
 sumed by erosion. We find traces of those lost lands in the 
 grains of vitreous quartz, which must have been a product of 
 
230 WALKS AND TALKS. 
 
 early precipitation. We find other traces in the conglom- 
 erates embraced in the old Eozpic rocks. We even find traces 
 in the slaty character of many of the pebbles, since much 
 alumina and silicate of alumina must have been liberated in 
 the progress of the chemical conflict, as already explained. 
 So when, at the end of the Eozoic ^Eon, vast beds were up- 
 raised which stand to our times, they were not the first land, 
 but only the first land which has survived to the human era. 
 
 XL/. THE WORLD \VITHOUT A. 
 
 REIGN OF INVERTEBRATES. 
 
 WE have followed the train of events down to a time 
 when the work of the geologic forces had become settled to 
 the tenor which was to be maintained through all the later 
 aeons. Uplift, erosion, sedimentation are the key-words to the 
 physical history of the world ; and these all express mere 
 sequences of a more fundamental action, COOLING. We are 
 now contemplating the world as it existed during the seon 
 designated Eozoic. I think, for reasons already stated, that 
 even then some areas of sea-bottom had been upraised to serve 
 as sources for the clearly fragmental materials laid down to 
 become Eozoic rocks. Where those crumbling lands were 
 located, we can not well conjecture. There may have been 
 clear, sun-lighted cliffs, beaten at times by dripping rains, 
 corroded by breaking waves all as in the human epoch. The 
 same mineral substances resisting the agencies of destruction ; 
 the same quality of sun-light, the same breeze blowing up 
 from the sea, the same ceaseless roar of the battle along the 
 beach. But it was a reign of the physical forces alone. The 
 wide sea was without a tenant; there were no bleached shells 
 strewn along the beach. No shrub contended with the surf 
 for the possession of the sandy foothold ; and no tree, how- 
 ever humble, held safer possession of the sparse soil gathered 
 in the chinks of the knotted cliffs. There was no form of 
 living creature seeking the ends of its being over all the 
 
THE WORLD AVITHOUT A BACKBONE. 231 
 
 stretch of the herbless land, and no wing of bird or insect 
 agitated the fervid air. It was in the progress of this reign 
 of physical forces that I expressed the opinion that vegetal 
 life may have made its advent in the sea. 
 
 The seons of the earth's infancy rolled on ; the first low 
 presages of coming continents had been ground to sediment ; 
 the only upraised examples of the primitive chemical precipi- 
 tates had been broken up and returned to the sea. Ov^r the 
 ocean's floor was accumulating a mud which, in a later age, 
 should be baked to granite and gneiss those granites and 
 gneisses which in our times, have become forms so familiar. 
 We have before us the evidence that at least fifty to a hun- 
 dred thousand feet of such sediments accumulated. The sea- 
 bottom bent down under its load. The downward protuber- 
 ance reached into an intenser heat than could be endured. 
 Besides that, the very thickening of the crust permitted the 
 interior heat to make encroachments upward, as already ex- 
 plained. The water which saturated the strata of simple frag- 
 mental sediments became intensely heated under a high press- 
 ure. Alkaline substances were dissolved by the heated water, 
 and the hot alkaline solution acted powerfully on the rock- 
 materials. They were partly dissolved even silica was dis- 
 solved ; they were partly softened ; they were brought to such 
 a state that the atoms were free to arrange themselves accord- 
 ing to their affinities in their new situation. The old sub- 
 stances were therefore made over into minerals which did not 
 exist in the sediments before. These minerals were formed in 
 juxtaposition to each other; and when, in a later age, the 
 temperature subsided, the mineral mixtures which constitute 
 Eozoic rocks of the various kinds were at hand. They formed 
 granites, syenites, diorites, and similar rocks, in which the 
 metamorphosis was so complete that the lines of original bed- 
 ding were obliterated. They formed gneisses and schists in 
 which the metamorphism was less complete. Of course, if 
 there were any calcareous remains of tenants of the sea, these 
 were completely dissolved, and we have no means of proving 
 that they ever existed. 
 
232 WALKS AND TALKS. 
 
 There was a time in the very remote past, when tidal 
 action on the earth must have been vastly more efficient than 
 at present. I have already remarked that the moon, if .dis- 
 engaged from the earth, as we argue, was once near enough to 
 produce an enormous tidal effect. When the moon was but 
 forty thousand miles from the earth, its tidal efficiency was 
 two hundred and sixteen times as great as now. The oceanic 
 tide, accordingly, would have risen six hundred feet twice 
 during each revolution of the earth, with a similar subsidence 
 in the interval. We can hardly conceive the effects of such 
 an occurrence. Think of such a mountain of water rolling 
 in. Think of the collision with the beach; think of the in- 
 undation which would bury the beach and sweep inland ; 
 think of the terrific erosion which would ensue ; think of the 
 same flood tearing back into the sea to repeat its invasion in 
 a few hours. How rapidly the land must have disappeared ; 
 how coarse the fragments hurled into the sea, and how remote 
 their distribution. If these events occurred during the accu- 
 mulation of any sediments which in our age have become 
 rocks, what vast beds of coHglomerates must there be. Do 
 we find them in the series of Eozoic formations ? No. There 
 are conglomerates, but not more bulky or coarse than in most 
 of the later formations. The conjecture was expressed by 
 Professor R. S. Ball that such high tides had occurred during 
 Palaeozoic time ; but we find no evidence of it nor even of 
 their occurrence during Eozoic time. As they must have oc- 
 curred, however, we may place them in an seon earlier than 
 that which witnessed the laying down of any sediments which 
 have been preserved to human times. 
 
 The end of the Eozoic JEon approached at last. Life had 
 appeared in the form of humble sea-weeds; and life had 
 throbbed into conscious being in the forms of the humble 
 Eozoon which I have before described. I can not admit that 
 no other forms of life found fitting home in the Eozoic sea; 
 but no demonstration of it has been discovered. We know, 
 however, that a vast thickness of rock-sediment was accumu- 
 lated, and that now very considerable areas were upraised to 
 
THE WORLD WITHOUT A BACKBONE. 233 
 
 constitute the beginnings of those lands destined to endure to 
 our time. Very likely the upheaval was accomplished through 
 many partial upheavals widely separated in time. But we 
 can only contemplate the total result. When the Eozoic 
 .ZEon was ended, and the Palaeozoic ^Eon begun, there existed 
 on the American side of the world, the following outcrops: 
 1. The Great Northern Land, lying north of the St. Law- 
 rence and the Great Lakes, stretching in one direction to the 
 coast of Labrador, and in the other, over the region between 
 Hudson's Bay and the Mackenzie River to the Arctic Ocean. 
 This sent a tongue across the St. Lawrence, at the Thousand 
 Islands, and extended into the Adirondack Highlands. 2. 
 The Seaboard Land, lying east of the present Appalachians, 
 and reaching on the north to New England and on the south 
 to Alabama. 3. The Cordilleran Land, covering .a large part 
 of the region west of the Great Plains stretching from the 
 crests of the eastern ranges of the Rocky Mountains into 
 California. Of its northern and southern extent we remain 
 in ignorance. Possibly this Cordillerau Land was more of 
 the nature of an archipelago than a continent. There were 
 smaller exposures of land, but we need not speak of them par- 
 ticularly. The rocks forming these continental nuclei are all 
 metamorphic. Between them and the rocks immediately over- 
 lying is an abrupt contrast. Why the process of metamor- 
 phism has been thus limited upward, has not yet been 
 explained. 
 
 These lands were outstanding at the beginning of the 
 Palaeozoic ^Eon. All else was sea. I am quite ready to be- 
 lieve, however, that other lands existed, since consumed by 
 the erosions which sought to lay the foundations of newer 
 formations. On the remoter side of this upheaval was an 
 ocean barren, if we can believe it, of all forms of animal life. 
 On this side was an ocean which suddenly teemed with the 
 shapes of sensitive creatures already of high rank, and diver- 
 sified in nature, but strange and archaic in their structures 
 and aspects. This sudden advent of hordes of creatures of 
 diversified types of life has been relied on as evidence that 
 
 20 
 
234 WALKS AND TALKS. 
 
 the Cambrian fauna did not originate by descent from any 
 older fauna. But you will easily infer that I take another 
 view of the facts. 
 
 Let us glance over these populations. There are first in 
 order and highest of all, the .Trilobites, which I have already 
 described. With them, in the very dawn of this jiEon were 
 Brachiopods few and feeble, but in Lingula as strong and 
 numerous as in any later age. Here grew also, calcareous 
 sponges not corals, but forerunners of corals not plants, 
 though rooted and fixed poor, humble creatures pinned help- 
 lessly to the sea-mud, appointed to an age when the work of 
 nature was still crude and unfinished, yet sensitive, capable, 
 undoubtedly, of suffering, and capable of enjoying life. Death, 
 certainly, was there, and pain. The Trilobite, in the very 
 attitude in which existence ended, reveals conscious suffering 
 and apprehension. We often find their forms closely rolled 
 together, as if shrinking from the felt approach of death. The 
 little trilobite, in his final repose, proclaims suffering and death 
 in the world before "sin entered." 
 
 Glancing down to the next epoch, we find other creatures. 
 Ah, this glance overleaps a million years or more. It is an 
 easy step for thought, but who can realize the slow rolling 
 years, the insensibly changing conditions through which nature 
 was fitted for the slight step in progress which the next epoch 
 reveals ? Here are trilobites still, and brachiopods and sponges; 
 and here are those huge orthoceratites of which I spoke ani- 
 mated sticks and logs suspended in the water long and slimy 
 tentacles projecting at the open end ; fierce, huge eyes look- 
 ing out for some other creature on which to feed; strong, 
 lance-shaped teeth with which to seize and tear him. From 
 this grim presence all other creatures fled away save those, 
 alas, which nature fixed in the soil and doomed to serve as 
 food for these monster molluscs. Here were meadows of 
 crinoidal forms which have already been described. Raising 
 their sculptured urns on gently waving stems, they spread 
 their jointed arms and fingers in search of their own aliment, 
 and were nipped for supper by some ravaging Orthoceras. 
 
THE WOELD WITHOUT A BACKBONE. 235 
 
 Here were banks of polyp corals each little creature planted 
 in his cup and expanding his petal-like tentacles in the life- 
 giving sunlight. Over this slope of animated stone crawled 
 lazy sea-snails grazing on the tentacled growths then beginning 
 a work of coral-building which the Florida reefs witness still 
 in progress. 
 
 The cycles of Cambrian and Silurian time swept on and 
 came to an end. The history of life showed no departure 
 from the fundamental types with which that history was in- 
 augurated. There were new species, new genera, some new 
 families, scarcely a new order or class. The changes were so 
 slow that the world seemed finished, and finished for these 
 happy creatures that held possession of it. Yet an occasional 
 visitor from another world would have noted changes. The 
 Cordilleran Land had sunken step by step, and was even now 
 reduced to an archipelago. The Great Northern Land, on 
 the contrary, had risen step by step, till its southern limits 
 extended from Albany to Syracuse and Buffalo, and thence 
 to Detroit, Mackinac, Milwaukee, and Chicago. North of 
 this line lay the continental surface. A great island stretched 
 perhaps, from Sandusky to central Kentucky. These lands 
 were the empire of silence and desolation. Populous as were 
 the waters, here was no motion or sound of animated creature. 
 Sparse, dwarf tree-growths fringed the bleak horizon, but 
 flower and fruit, grass and herb, were yet unknown. The 
 sea, always jealous of the conquests made from his domain 
 continued to growl around the borders of the land, and pur- 
 sued industriously the work of reclamation of his ancient 
 slime. The wandering winds finding no fertile isle to fan or 
 sail to waft, confederated with the destroying waves wreaked 
 their anger on the crumbling shores and howled sullenly 
 through the vistas of the sparsely wooded plain. 
 
236 WALKS AND TALKS. 
 
 XL/I. THE DYNASTY OF" KISHKS. 
 
 DEVONIAN AND CARBONIFEROUS TIMES- 
 
 WHEN the morning of the Devonian Age dawned, a new 
 form was seen moving in the populous sea. It was a verte- 
 brate form. Without a bony skeleton, its cartilaginous frame- 
 work and general plan embodied a new conception. Among 
 vertebrates its organization was decidedly low; but it was not 
 a fish in any ordinary acceptation of the term, though w"e 
 shall have to call it a fish. There were other vertebrate forms 
 more clearly fish-like, but all widely separated from modern 
 fishes. One could easily distinguish three types of these 
 archaic vertebrates. They are known among us as E-las'-mo- 
 brancJis, Plac'-o-derms and Gan'-oids. The Elasmobranchs are 
 a group which still survives. They are all shark-like. The 
 kinds which lived in the Devonian were true sharks (Sel'-a- 
 choids) of the peculiar Ces-trac'-i-on family, the best known 
 species of which ranges from Japan to New Zealand. Cestrac- 
 ion, the Port Jackson Shark, has spines in front of both the 
 dorsal fins; the nostrils unite in the cavity of the mouth, and 
 the upper lip is divided into seven lobes. The teeth along 
 the middle of the mouth are small. External to these are 
 large flat teeth twice as broad as long, arranged in oblique 
 series so as to form a sort of tesselated crushing surface. 
 
 Among the very earliest American fishes were some of 
 these spine-bearing sharks. The spines are flattened, two- 
 edged like a bayonet, and curved as if one had belonged to 
 the right side and the other to the left. The external surface 
 was covered with a thin coating of enamel, sometimes smooth, 
 sometimes ornamented. These spines are not attached by a 
 joint, but inserted in a mass of cartilage imbedded in the 
 flesh. They were perhaps the front rays of the pectoral fins. 
 Some of them were more than a foot in length. Being two- 
 edged and very sharp, they must have been very powerful 
 weapons, offensive or defensive. These cestracionts were 
 numerous during the Corniferous period. Their smooth, 
 brown spines are very often found in the Corniferous lime- 
 
THE DYNASTY OF FISHES. 237 
 
 stone of New York, Canada, Ohio, and Michigan. If you 
 wish the name, here it is: " Mach<xr"-a-cari-ilius, or "Dag- 
 ger-spine." 
 
 Another type among the earliest American fishes was 
 (Rhyn'-cho-dus, or " Beak- tooth ") a form related to the Chi- 
 mce'-ra, which also resembles sharks. It has, however, a long, 
 whip-like tail ; its gill-slits are covered by a flap of skin, and 
 the skull is blended with the jaws. The teeth consist of mi- 
 nute denticles firmly massed together into large tabular plates 
 which are inseparably blended with the jaws. It has a long 
 and powerful spine in front of each dorsal fin. The only 
 known specimens of Rhyrt 'chodus are found in the Cornifer- 
 ous Limestone of Ohio ; but it must have had a much wider 
 range. 
 
 Another of the most common and most striking fishes of 
 the same age appears to have been a relative of the modern 
 sturgeons a family of plated Ganoids. Our American geolo- 
 gists have almost buried it under a pile of nomenclature, 
 which they have finished in the following shape : Mac-ro-pet- 
 al-icli'-thys or "Big-plated fish." These fishes were of large 
 size. The cranium was composed of large polygonal plates, 
 united by double sutures which are nearly concealed by the 
 tubercled enameled surface; the .tubercles are stellate; the 
 surface is ornamented by double rows of pores and single 
 thread lines, forming a pattern which does not correspond 
 with the plates below. These large, geometrically formed 
 plates often attract the attention of quarrymen, since they 
 are sometimes fifteen inches in length. 
 
 In this assemblage of oldest American fishes, we have to 
 mention one more. This is a ganoid by the name of 0-nych'- 
 o-dus or "Hook-tooth." It was of large size. The cranium 
 was composed of a large number of bony plates covered with 
 an enameled and tubercled surface. The borders of the jaws 
 were set with a row of conical, acute, more or less recurved, 
 teeth ; and, in the middle of the lower jaw in front, was a 
 single series of large, curved, conical teeth, presenting a strik- 
 ing appearance, and often found imbedded in the Corniferous 
 
238 WALKS AND TALKS. 
 
 Limestone. The body of the fish was covered with rounded, 
 overlapping, bony scales nearly circular in outline, and about 
 an inch in diameter. 
 
 Please notice that these oldest American fishes, dating 
 from the Corniferous Period, are Elasmobranchs and Ganoids. 
 Of the former, there were two types, Cestracionts and Chi- 
 mseroids. Of the latter, also two types related to sturgeons 
 and gar-pikes. 
 
 I must now inform you that fish-like creatures began exist- 
 ence earlier in the Old World than in the New at least, 
 that is the opinion long entertained, though we shall probably 
 have to abandon it when our information is more complete. 
 In the Upper Ludlow rocks of England, which form the 
 upper part of the Silurian, is a "bone-bed" composed almost 
 entirely of the remains of fishes, much triturated and matted 
 together. From this bed spines of Ori-chus have been 
 obtained a fish apparently belonging to the Cestraciont type 
 of sharks. In the Upper Ludlow have been found, also, por- 
 tions of Geph-al-as'-pis, or "Shield-head," having the head 
 covered by a broad plate. This fish was intermediate between 
 Placoderms and Ganoids. Still lower down in the "Lower 
 Ludlow," relics of a similar fish called Pter-as'-pis or "Wing- 
 shield" have been found. So we say the oldest fishes of 
 Great Britain lived in the Silurian Age. We know also, that 
 very similar fishes dwelt contemporaneously in the waters 
 which covered Russia and Bohemia. 
 
 I have next to inform you that this record is beaten by 
 America. It has very recently been announced by Professor 
 Claypole that the Corniferous Period was not the earliest date 
 of American fishes. He finds remains of fishes in the lower 
 and upper portions of the Salina Group of Pennsylvania. 
 They appear to be related to Placoderms and Ganoids, and he 
 has bestowed on them the name Pcd-ce-as'-pis or "Ancient 
 Shield." Still lower than this he reports some fish remains 
 which he thinks may be referred to the genus On-chus. These 
 are at the bottom of the Clinton Group, which in Pennsyl- 
 vania is fifteen hundred feet below the Corniferous Limestone, 
 
THE DYNASTY OF FISHES. 239 
 
 and is two formations lower than the oldest fish-remains of 
 Europe. 
 
 We have now stirred up all the old bones the oldest 
 bones buried on our planet so far as we know. But I do 
 not think we have found the first fishes yet. There must have 
 been some forms still less like fishes than these. Perhaps if 
 we could carry the line back, we should find fish-like creatures 
 approximating more and more to crustacean creatures. There 
 was Pter-y-go '-tus in the Old World and America, and Eu-ryp r - 
 te-rus plentiful in America, with its extended pair of arms re- 
 minding one forcibly of the Pter-ich' '-thys or "Winged-fish" 
 of the Old Red Sandstone. There was Cephalaspis, with its 
 broad head-shield exceedingly similar to the shield of the 
 modern King-crab and some of the old trilobites. Other in- 
 timations exist of a possible near relationship between these 
 half completed vertebrates and the dying-out forms of Crusta- 
 ceans. But these are questions which must be left to the 
 future. 
 
 These relations enable us to contemplate with new interest, 
 some of the despised fishes which live in our times. Our 
 sturgeons, gar-pikes, and sharks are the sparse representatives 
 of those ancient families which once sustained alone, the dig- 
 nity of the vertebrate type. In their forms was first 
 enshrined the conception of the vertebrate plan of structure 
 which was destined to remain on the earth under its various 
 modifications, until man, the thinking and ruling vertebrate, 
 should arrive. Of these ancient families, the placoderm was 
 destined to disappear with the Devonian, and without a suc- 
 cessor. The sturgeon-type has survived in a slender line of 
 representatives, to the human epoch. The cestraciont sharks 
 were probably differentiated into the various better known 
 families of modern sharks, but continue to our times, to exem- 
 plify the probable nature of old Onchus, patriarch of sharks. 
 The bony scaled ganoids more fish-like than any of the 
 others, both in form and scaly covering, were well represented 
 by Onych'odus. The power and numbers of their family con- 
 tinued to increase through Carboniferous and Mesozoic times; 
 
240 WALKS AND TALKS. 
 
 but then they dwindled away. In modern times, our famil- 
 iar bony-scaled gar-pike haunts the freshened waters of river 
 and lake the poor degenerate descendant of ancestors which 
 once dominated over the world. Venerable relic of a mighty 
 empire! Were the lineal descendant of Menes or Nebuchad- 
 nezzar to stand before me, the antiquity of his lineage would 
 inspire my interest and veneration, but it would be as yester- 
 day compared with the lineage of this poor gar-pike. 
 
 Why have these creatures been preserved in existence so 
 long? The march of organic improvement has advanced for 
 thousands upon thousands of centuries, and left them far in 
 the rear. These forms are misplaced in the modern world. 
 They constitute an anachronism, which is either an absurdity, 
 or a phenomenon too full of meaning for ordinary compre- 
 hension. The gar-pike destroys our game-fish and our market- 
 fish as he ravaged neighboring kingdoms while he ruled an 
 empire of his own. He tangles and tears the nets of the 
 fishermen, who visit their execrations upon him. His flesh is 
 unpalatable for food. The mud-loving sturgeon, less destruc- 
 tive in his nature, brings no utility into the modern world. 
 The fierce shark, equally unfit for food, is the free-booter of 
 the ocean. Other fishes furnish aliment to man. They came 
 from unknown realms to meet man here, and serve his ends. 
 But these archaic types linger from a time when human wants 
 had as yet no existence, when human food was not demanded. 
 They were never intended for food, since they made food of 
 every other creature. These useless and destructive beings 
 are out of joint with the world and with history. Why are 
 they here? 
 
 Why ? They come to import ideas into the modern world. 
 They bring down to us living illustrations of faunas passed 
 away. The plates of Cephalaspis and the spines of Machcera- 
 canthus quarried from the rock might pique our curiosity and 
 distress us by their mystery ; but they would not instruct. It 
 was intended that the intelligence of the being which always 
 stood as the finality of organic improvement should grasp the 
 conception of the world, and reproduce the grand history of 
 
THE DYNASTY OP FISHES. 241 
 
 departed cycles. Why? It was an act of beneficence which 
 saved these relics of ancient dynasties from total destruction. 
 There was purpose, not accident, in the failure of their com- 
 plete extinction, and the assignment of the world exclusively 
 to more modern creatures. These are precious examples pre- 
 served in a museum. These are caskets filled with documents 
 from an olden time. The gar-pike and the sturgeon and the 
 shark are missionaries from the past to the present. Hear 
 them. They are preaching to man's intelligence. They are 
 Unfolding the plans of Infinite Wisdom. "He that hath ears 
 to hear, let him hear." 
 
 . SCENES KROM: THE COAL, 
 
 HOW THE COAL BEDS WERE FORMED. 
 
 WHILE the grizzly monsters of the ancient deep were 
 luxuriating in empire and blood, the premonitions of progress 
 were felt. The world was not made for them, but only an age 
 of the world. Behold, the tide bears out into the sea a float- 
 ing log. Its exterior is marked by peculiar and significant 
 impressions. They reveal the crest of a dynasty in the 
 vegetal world. They are the seal of a Sigttla'ria, or the scars 
 of a Lepidoden'dron. It has floated from the shore of a low- 
 lying and silent continent. The, re is a meager nursery there 
 where nature is training vegetation for thriftier times. In this 
 log is written the doom of the old Placoderms which had 
 stirred the Devonian mud of the Ohio sea-bottom. It is a 
 voice crying in the wilderness of waves, Prepare the way for 
 new land, new forms, new scenes, and new history. 
 
 It was the beginning of the Carboniferous Age. The 
 tremors incident to the upthrow of a new belt of land had 
 strewn the submerged continental slope with the sandy ruins 
 of older lands, and left the bed to mark the beginning of a 
 new system of strata. We know these hardened sands as 
 Waverly Sandstone and Marshall Sandstone. They were not 
 outspread in a day. There was a chapter of the world's organic 
 history enacted while these formations were laid down 
 
 21 
 
242 WALKS AND TALKS. 
 
 destined to be torn up in the human age, to serve as founda- 
 tion stones for more elegant structures. Through another age 
 still, the impending events, heralded by the floating log, were 
 destined to be delayed. Meantime the waters deepened, and 
 nature seemed to have forgotten her announcement. She had 
 promised land and green forests; she gave deep sea and an 
 expansion of the empire of bony-scaled ganoids. She gave 
 larger development to Brach'iopods ; she dallied with the 
 chambered shells, and gave the world an improved type, which 
 we have named Go-ni-a-ti'-tes. She lingered lovingly over one 
 of her ancient conceptions which we style crinoidal. She had 
 had it in her repertory of beautiful thoughts since early Cam- 
 brian times the pretty little stone lily. She had taken it up 
 in every age, and had turned off some improvements and some 
 new decorations. But now, during this waiting period, she 
 seems to have returned with true devotion to one of her first 
 ideas. She gave great attention to diversifying it, decorating 
 it, and filling the sea with its delicate and graceful forms. All 
 for the Age not for perpetuity ; for if, while we stand on 
 this verge of a grand epoch, we lift the veil which separates 
 the one beyond, we find the crinoidal conception gradually 
 falling into forgetfulness. Larger works occupied the hands 
 of nature, and she finally set apart the deep sea for the pres- 
 ervation of a few crinoidal illustrations for man's instruction, 
 and left them to await the last age as the European aurochs 
 still lingers in the protected forests of Lithuania, and the 
 American bison will continue to flourish in the Yellowstone 
 Park. 
 
 This dream of placid waters and teeming populations was 
 broken by a jar. Some stay of the long pressed crust of 
 the earth was broken by the accumulated strain, and the mud 
 of the sea was stirred from its prolonged repose, and floated 
 over the fields where stone-lilies had flourished, generation after 
 generation. Tenants of the sea alarmed, retreated to deeper 
 waters or perished in their homes, and received a Pompeiian 
 burial. The ocean-bottom had been lifted to a higher level. 
 The scene was totally changed. The summer sea became a 
 
- SCENES FROM THE COAL PERIOD. 243 
 
 stormy and turbid shore ; and a broad belt was given to the 
 land. The torn beach, crumbling before the waves, contrib- 
 uted coarse rubble for the foundations of new land .in some 
 future age. The vegetation promised for the impending epoch 
 was crowding into possession of the ground. It flung its frag- 
 ments into the deep in challenge to the conflict which now 
 sent its murmur through the world. These chips from the 
 by standing forest were buried in the sands which loaded the 
 sea-bottom. Every thing was ready ; the curtain was about 
 to rise. 
 
 Now came the first charge in the conflict destined to alter- 
 nate during an age; another collapse of some of the stays 
 and supports of the rigid crust. The land uprose by another 
 notch ; the bottom of the sea was lifted to the surface. The 
 great " Carboniferous Conglomerate" was now first bathed in 
 air and sunlight. The continent of North America received 
 an annexation of territory which stretched from the Seaboard 
 Land east of the Appalachians, to the Great Plains. The new 
 territory included all the regions which had been selected as 
 the sites of the capacious coal repositories, for the use of 
 civilization. It was not a dry upland. It was a broad and 
 mighty marsh. Michigan was not included in the common 
 continental marsh, but stood apart for a special destiny. 
 
 Now, over all this breadth of bog and swale sprang tip 
 vegetable growths trees and -herbs, ferns and rushes, with 
 the all-engrossing airs of those who come to hold possession. 
 Whence these forms? Some, as I said, had been nursed on 
 the older and contiguous land, and now entered upon a new 
 possession because it was fit. Some sprang from germs fresh 
 planted by some unseen hand. What mean all these trans- 
 formations? They mean progress. They mean man. They 
 mean civilization. It is not alone change ; it is improvement. 
 This luxuriant crop is sustained by the carbonic acid of the 
 atmosphere. This, as is generally supposed, was in excess. 
 It made the air irrespirable ; no terrestrial creature could 
 live. But terrestrial animals must constitute the next step of 
 progress. The march of improvement had now gone as far 
 
244 WALKS AND TALKS. 
 
 as possible with water-breathing populations. The highest 
 type of animals had been reached and its aquatic class had 
 lived a Striking career. Nature had now paused for the puri- 
 fication of the air for the next class. The plan of nature was 
 blocked till this could be done. 
 
 The Power which had called matter and force into exist- 
 ence, could have made other disposition of this difficulty. 
 The carbonic acid could have been combined with lime and 
 fixed in limestones. It could have been banished from the 
 planet. But carbon is precious. It is the basis of all our 
 combustion. It warms and blazes in coal and petroleum, 
 peat and gas. The carbon must be preserved for future use. 
 Man would discover its utilities, though the age then passing 
 had no use for it. Man was yet far off; but man was antici- 
 pated ; man was involved in the plans of the world ; man 
 was prophesied in these preparations. 
 
 So vegetation was appointed to do the work and conserve 
 the material. This explains the presence of coal-making trees 
 upon the shores of the preceding epoch. They came by ap- 
 pointment, they were to fulfill a plan ; they stood waiting by 
 the border of a domain which had been promised them for a 
 possession. All the conditions favored. This was not fortui- 
 tous ; it was a preparation. Unlimited supplies of aliment 
 pervaded the atmosphere. The marshy situation exhaled the 
 abundant vapor in which vegetation delights. The earth in 
 its comparative newness, retained the warmth to stimulate at 
 the root. So tree-fern and herbaceous fern, calamite and 
 sigillaria, begin work. Atom by atom, they selected the poi- 
 son from the atmosphere, and, returning the oxygen, fixed 
 the carbon in their tissues. Frond, stem, and root treasured 
 up the fuel, impelled by the force of sunlight ; every pound of 
 vegetable answered to a given amount of solar force. 
 
 The work was begun. Generations of plants succeeding 
 each other, fell prostrate at last, and added their substance 
 to the growing bed of peat. Standing water protected the 
 peat from decomposition. Now the skies again were lowering 
 and forebodings of change trembled through the continent. 
 
SCENES FROM THE COAL PERIOD. 245 
 
 A cataclysm was at hand. The wide expanse of marshy land 
 again went down. Old ocean, which had roared and frothed 
 in rage around the borders of the territory of which he had 
 been dispossessed, came careering back to his old haunts. 
 He brought a freight of mud and sand, and spread it over 
 the whole vast peat-bed as if to make sure of no renewal of 
 the usurpation like those who sow with salt the sites of 
 ruined cities, to make the ruin a ficality. But the salt sowed 
 by resentful ocean was in truth, a packing away of something 
 destined to be saved, not forgotten. It was part of a benefi- 
 cent plan, and the anger of the ocean was made an instru- 
 ment for its accomplishment. Beds of clay and sand shut 
 out from the atmosphere the sheet of peaty matter which was 
 to lie and consolidate to coal. 
 
 The dominion of the ocean was temporary. Apparent re- 
 gress was in truth a forward movement. Again the reeking 
 sea-bottom came up to sunlight, and another scene of bright 
 verdure was spread where late, old ocean had celebrated a 
 jubilee. It looked as if the former forest had undergone a 
 resurrection. Here stood again Lepidodendron in its summer 
 hat, and Sigillaria and the other established forms. But 
 they were other species ; and with them was an occasional 
 new comer among the vegetable types. They understood for 
 what purpose they had been sent. They resumed the work 
 of selecting the impurity from the air. Already, some ad- 
 venturous and hardy types of air-breathers had colonized the 
 jungle. They were sluggish and slimy creatures, with whom 
 life passed slowly, and respiration was a matter of compara- 
 tive indifference. Yet they enjoyed existence. They grazed 
 on the humble herb ; they seized the dragon-fly, alighted to 
 rest his wing ; they violated the home retreats of the passive 
 snails. They crawled out and sunned themselves on the ferny 
 bank. There were grosser and heavier forms, mail-clad and 
 vociferous ; haunting the bayou ; paddling for some eligible 
 fishing station ; bellowing like oxen, when excited in pursuit ; 
 stirring up the mire of the stagnant bay ; resting their chins 
 on the reeking bank to absorb the slanting sun-warmth of the 
 
246 WALKS AND TALKS. 
 
 early morning, or lolling under the noonday shade of some 
 wide-spreading and umbrageous Lepidodendron. 
 
 At the entrance of the bay was an exposed headland. 
 From this the high beach stretched away for miles ; and 
 already the older coal deposits were exposed along the eroded 
 cliffs. Here the waves pounded up beds of sandstone, shale, 
 and coal. The sands were deposited along the beach which 
 faced the open sea. The finer and lighter materials were 
 floated off in search of a quieter nook. In the bay they found 
 a retreat from wind and waves, and there laid themselves 
 down in a mixture of comminuted coal and clay. In a later 
 age, the deposit was a bed of cannel coal. 
 
 Why prolong the tale ? The land continued to oscillate as 
 long as the purification of the air was incomplete. Again and 
 again, the forest resumed its work, and bed after bed was stored 
 away beneath ocean sediments, to await the end. When the 
 beneficent work had been accomplished, the tired forces, that 
 had endured with trembling and vibrations, the enormous 
 strain that had been accumulating under the prolonged con- 
 traction of the interior, yielded with a tremendous collapse 
 which jarred the hemisphere. Huge folds of the massive 
 crust uprose, and were mashed together till their crests pierced 
 the clouds. This was the birth of the Appalachians. This 
 event proclaimed the end of the long Palaeozoic ^Eon. Only 
 the stumps of those folds remain to-day. Though crumbling, 
 they stand as monuments of the mighty throes through which 
 the world was prepared for man and civilization. 
 
 XL/HI. THE R.E:PTILE 
 
 MESOZOIC EVENTS. 
 
 THE storm is cleared, and a new sky overhangs the scene. 
 We seem to be in another world. We glance over the terri- 
 tory lately covered by luxuriant coal-vegetation, and Cycads, 
 and Voltzias now hold possession. The Cycads are palmetto- 
 like in form, fern-like in foliage, and pine-like in affinities ; the 
 
THE REPTILE MONARCHIES. 247 
 
 Voltzia seems a progenitor of the cypress. No Lepidodendron 
 or Sigillaria raises its green crown in all the wooded landscape. 
 The reeking marsh has disappeared, and an undulating up- 
 land occupies the continent. We glance over the place of the 
 great flat which had stretched from New England to Ala- 
 bama, and dark-wooded ranges of mountains frown down on 
 us. We search for the old shore-line which had set the 
 bounds to the empire of the sea, and it is removed. Far 
 southward it lies, within two hundred miles of the Gulf-border 
 of the human epoch so much more of the ocean's domain has 
 been wrested from his possession. 
 
 We range over this new bright landscape. All the old 
 Palaeozoic forms of animal life are displaced. Strange tenants 
 have moved in. Instead of the feeble, lizard-shaped Amphib- 
 ians which housed themselves in a hollow stump, we find great 
 quadruped-like Labyrin'thodonts crawling like enormous toads 
 under shelter of a fringe of forest. Their ponderous bulk im- 
 presses deep foot-prints in the sand along the beach four- toed 
 and hand-like destined to remain and become a wonder, of 
 the human age. (See also Talk XXX.) 
 
 But the Amphibians have yielded empire to another 
 dynasty. Great was Archegosaurus, but Deinosaur was greater. 
 An extraordinary and amazing figure reveals itself stalking 
 along over the beach. Evidently this monster, tall, scale- 
 covered, erect, with diminutive head, swollen abdomen, and 
 massive, trailing tail, is a representative of the ruling family. 
 He reveals massiveness without elegance; strength, without 
 grace. He marches on two feet and leaves a foot-print three- 
 toed like that of a bird. His jaws are armed with strong, 
 sharp-edged, and pointed teeth. His long bones are hollow 
 like those of birds ; the pelvis, as well as the foot, is bird-like ; 
 the sacrum has four vetebrse like that of a mammal ; the 
 neck-vertebrae are concavo-convex a's in mammals, and his lower 
 jaw has lateral motion for triturating food, as in the ox. 
 Shape like a frog; head, tail, and scales like a lizard; feet 
 like a bird ; sacrum like a mammal what shall we call the 
 creature ? 
 
248 WALKS AND TALKS. 
 
 We watch him through his sea-side promenade, and fol- 
 low him to the dank and peaty jungle where he finds his 
 home. We see him browse from the lower tufts of foliage, 
 and grind the fibrous twigs with the jaw-movements of a her- 
 bivore, wearing away and blunting the crowns of his teeth. 
 But he 'meets his enemy another Deinosaur of bloodthirsty 
 disposition, a flesh-eater, and armed with sharp and lacerating 
 teeth. Between the two a bitter feud exists, and they have, 
 at former times, clenched in the struggle for prowess. The 
 herbivore recognizes his superior; but unwillingly subject, 
 fierce auger flashes from his dark eye, and with a defiant, un- 
 christian growl, he makes room for the contemptuous and 
 bloody carnivore to pass. 
 
 There are others of the ruling dynasty which disport 
 themselves in the waves ; but these sea-saurians (Enaliosaurs) 
 are only the forerunners of an army which is marching down 
 the course of events, and may be expected in the morning of 
 another age. There are also others. We walk in the twi- 
 light of a Mesozoic day, along the reedy shore of a gloomy 
 estuary, and the crocodiles are crawling out on the land for 
 midnight prowling. A broad crocodilian grin reveals an array 
 of cruel, conical teeth set in the jaws ; and their lazy forms 
 are encased in a jointed bony cuirass, which fits them for de- 
 fensive warfare. When Bel'odvn moves through the jungle, 
 even the Deinosaur is startled from his security. 
 
 Within the limits of that recess of the continent destined 
 to be named New England, is a deep and narrow bay, which 
 projects far northward from the future shore of Long Island 
 Sound. We stand upon the gneissic slope of the western 
 shore, and survey the shining expanse. The tide is out, and 
 the smooth sand beach is laid bare. Over its surface lie 
 squirming and crawling and shrinking from exposure, the 
 sundry forms of marine life which the last tide brought up. 
 This is the opportunity for the land-marauders. Now they 
 hurry to the scene in search of a meal. There, most conspic- 
 uously, strides the tall uncouth Bron-to-zo'-um, a three-toed 
 Deinosaur, standing fourteen feet high. Its foot is twenty- 
 
THE REPTILE MONARCHIES. 249 
 
 four inches long. At times it drops on four feet to seize a 
 dainty morsel of a crab, and leaves, for a space, the foot-prints 
 of a quadruped. But the forward feet are comparatively di- 
 minutive in size. In the distance, Oto-zo'-um paces along the 
 beach another bipedal Deinosaur, but with four toes behind. 
 With foot twenty inches in length, he has a stride of three 
 feet, in a leisurely gait. Otozo'um is partaking of his meal. 
 Now and then he picks up a stranded fish. Among these 
 gigantic figures more humble Deinosaurs are seen mingling. 
 One of these leaves a foot-print but three inches; and we 
 notice one wee pet of a reptile which makes a track but a 
 quarter of an inch in length. They are all engaged in re- 
 freshing themselves. This is the regular symposium of the 
 reptiles. 
 
 Let us wait here for the tide to come in. It is coming ; 
 and announces itself by its roar. The tide of the open sea is 
 here augmented by the limits of the narrowing bay, and it 
 swells into a terror-striking "bore." The Deinosaurs and 
 Labyrinthodons hear the sound, raise higher their heads in 
 listening attitudes, and scurry away to their retreats. The 
 tide lingers awhile, dallying with the sands, and making love 
 to the shore. Now, at the appointed time, it presses a dewy 
 parting kiss upon the beach which it fondled for an hour, and 
 retires. Where now, are the foot-prints of those gigantic sau- 
 rians? Has the dallying tide erased them? No. It has 
 covered them with a soft film of fine sand. They are not de- 
 stroyed ; they are preserved. The table is spread again with 
 squirming viands, and the saurians recognize another call to 
 refreshments. Again they range along the sand, and impress 
 their tracks in the soft surface. Unconsciously, these crea- 
 tures are inscribing their autographs on the pages of the 
 world's history. The tide returns and spreads its conservative 
 sands again over the well-inscribed beaches. And so the tide 
 rolls in and out, and the saurians write their daily chapters of 
 history. By and by the tides will cease ; this bay will be up- 
 lifted beyond their reach ; these sands will become a solid 
 brown sandstone ; quarrymen will ply their avocation along 
 
250 WALKS AND TALKS. 
 
 the slopes where Otozo'um breakfasted ; the stony slabs will be 
 split apart, and there will be found, in all their details, the 
 same footprints made in this opening epoch of the Middle 
 Ages of the continent's history. 
 
 So the years rolled on ; and meantime the vegetable king- 
 dom was performing its part in the drama of the world. There 
 must have been lowlands where water-loving trees stood and 
 bathed their feet swamps, where fallen foliage and worn-out 
 tree trunks gathered themselves in beds of peat that hardened 
 into coal. One of those tracts is a few miles west of Rich- 
 mond, Virginia; and two others are in the Deep River and 
 Dan River regions of North Carolina. Good coal was 
 formed, quite similar to the bituminuous coal of the Carbonif- 
 erous Age. 
 
 The Triassic Age came to a close through movements of a 
 nature similar to those which closed the Carboniferous, but 
 less pronounced in violence. The sandy beds were disturbed 
 and tilted, all the way from Nova Scotia to North Carolina. 
 The strains which they suffered caused great fractures which 
 intersected the formation in straight lines; and from below 
 came molten mineral matter which filled the fissures. The 
 matter was of a basaltic character, and in places where it 
 overflowed on an extensive scale, it assumed a columnar struc- 
 ture. We note especially four regions of Triassic sandstones 
 and Triassic eruptions : Western Nova Scotia, the Connecti- 
 cut Valley, the Palisade region, extending through New 
 Jersey and Pennsylvania, four others in Virginia, and two 
 in North Carolina. The coarse Potomac marble is from the 
 lower part of the Trias. 
 
 It is now the middle part of the Mesozoic ./Eon. We are 
 in the midst of the reign of reptiles. This dynasty is even 
 more pronounced than was the reign of fishes. From the 
 thought of a reptile we shrink away. To pronounce a man a 
 reptile is to bury him beneath contempt. Think of the rep- 
 tiles which we know crawling, skulking, lazy creatures, all 
 all save the agile lizard. But now, in this reign of reptiles, 
 we find an enlargement and diversification of the type which 
 
THE REPTILE MONARCHIES. 251 
 
 amazes us; it even awakens our admiration and interest. 
 Down by the sea-shore Mesozoic saurians amuse themselves in 
 the surf. The Ich'-thy-o-saur, with thick and fish-like form 
 and alligator head, pursues the fated fish into the deeper 
 water, guided by a pair of enormous eyes which gather in the 
 feeble light. The swan-like neck and head of the Ple'-si-o- 
 saur rises above the surface, while the short, thick body is 
 propelled beneath by a pair of long, flat, many-fingered and 
 many-jointed paddles. There too, winds the progenitor of the 
 sea-serpent a real sea-serpent, whatever fable may connect 
 itself with the modern ore. This is the Mos'-a-saur, attaining 
 sometimes a length of eighty feet. The body is covered with 
 small, overlapping bony plates. The paddles are five-fingered 
 and resemble those of whales. 
 
 Contemporary with the sea-saurians are those of the estu- 
 ary and the river. Turtles and tortoises sun themselves on 
 the naked slopes. Real lizards scamper over the cliffs, or 
 skulk among the debris of the forest. But most conspicuous 
 of all move the gigantic Deinosaurs. Some swim in the sea; 
 some crawl on the land; some scud among the branches of 
 the trees, and other forms standing erect, walk in reptilian 
 majesty among their humble subjects. 
 
 Here is the Had'-ro-saur, whose province is limited to the 
 Atlantic border. His near relative, the Ig-uan'-o-don, holds 
 some provinces in the Old World. These are vegetable eaters. 
 But here is their traditional enemy the carnivore. Lce'-laps 
 disputes supremacy with the Hadrosaur, as in the Old World, 
 Megalosaur rivals Iguan'odon. Strangest of all, for a rep- 
 tilian modification, the Pter'-o-saur sails over our heads and 
 shadows us with his broad leathery wing. The Pterosaur is a 
 ground disputed between reptiles and birds. In aspect, bird- 
 like, he is, however, essentially a saurian. In structure he is 
 less bird-like than the Deinosaur. 
 
 What a range of adaptations is this ; sea, river, shore, 
 upland, forest, jungle, and atmosphere all populated by fit 
 modifications of a single type of vertebrates ! But we stand 
 still more amazed. Before we make our exit from this 
 
252 WALKS AND TALKS. 
 
 wonderful mesozoic time, behold a real bird on the wing. 
 Clothed with proper feathers and constituted a bird, it is yet 
 reptilian. Its long and lizard-like tail, vertebrated to the ex- 
 tremity, is furnished with proper quills, but can not conceal 
 its kinship with the reptiles. It comes out of the empire of 
 reptiles and brings reminiscences of the reptiles with it. 
 
 A higher type is now standing at the threshold of being. 
 A knell is sounding the funeral of the reptilian dynasty. The 
 saurian hordes shrink away before the approach of a superior 
 being. After a splendid reign, the dynasty of reptiles crum- 
 bles to the ground, and we know it only from the history 
 written in its ruins. 
 
 XL/IV. MAMNtALIAN R.ULE. 
 
 OENOZOIC TIMES. 
 
 THE striking figures which appealed to our wonder during 
 our walk through the Mesozoic ^Eon, diverted attention from 
 some very humble but very suggestive creatures which man- 
 aged to elude the dangers threatening them under a rule 
 which knew only cruelty and extermination. These creatures 
 were little mammals. Only one species is known to have ex- 
 isted in America ; and we are indebted to Professor Emmons 
 for bringing to light its remains in the red sandstone of North 
 Carolina. The lower jaw is armed with a series of teeth 
 somewhat like those of the common mole. It seems, there- 
 fore, to have been insectivorous. Its nearest relative among 
 living mammals is the Banded Anteater of Australia, a small 
 animal with a fox-like appearance. We call it Drom-a-the'- 
 ri-um, or " Running-beast." It is singular that a very similar 
 mammal lived in the same age in the Old World. Some of its 
 remains have "been found at Wiirtemberg, and others, at 
 Frome, England. Another Triassic mammal has recently 
 been described by Professor Owen from South Africa, as large 
 as a gray fox, and remarkably specialized. All these mam- 
 mals are most distinctly mammalian. They do not look like 
 
MAMMALIAN RULE. 253 
 
 first attempts of nature. There is nothing transitional about 
 them. They bring with them no reminiscences of reptiles, 
 birds, or fishes. If they had descended from humbler forms, 
 it must have been by many generations ; and many connect- 
 ing links must be totally lost. If these facts were an iso- 
 lated group, we mi^ht think these little mammals abruptly 
 ushered into being; but the question receives light from so 
 many directions, that we must at least hesitate to accept 
 that view. 
 
 Whatever the origin of these little fore-runners of a noble 
 type, it can not be supposed they had no companions. There 
 must have been hundreds, if not thousands, of individuals of 
 each of these species, but they are wholly lost to knowledge. 
 Where we are sure of the disappearance of so many remains, 
 how easy to believe the remains of different creatures of 
 lower mammals have also disappeared. 
 
 Mammals once in existence, we are compelled to believe 
 that they continued uninterruptedly in existence until our 
 own times. We can not admit that the type was lost to the 
 world, and then the same identical conception reintroduced. 
 But where did mammals live ; where did they perish ; where 
 lie their bones ? Save one or two thin bone beds, we search 
 in vain the depth and breadth of Jurassic and Cretaceous 
 strata for evidences of the existence of mammals. In a bone- 
 bed of the Stonesfield Slate of the English Jurassic, the teeth 
 and jaws of several species of mammals have been found. 
 These are mostly near relatives of the Triassic mammals. In 
 the Middle Purbeck of the Upper Jurassic, occur other remains. 
 We know in Europe, all together, not much over fourteen 
 species, and they are probably all marsupial ; and a majority 
 are insectivores. In the Jurassic of America, Professor Marsh 
 has brought to light at least 17 species ; and these all closely 
 resemble the Old World remains. In all the vast thickness of 
 the Cretaceous strata, but a single species is known, and of 
 this so far as I am informed, but a single individual, and this 
 very imperfectly preserved. It comes from Dakota, and was 
 described in 1884 by Professor Cope, who bestowed on it the 
 
254 WALKS AND TALKS. 
 
 name Men-is-co-es'-sus. This also, is similar to the Old 
 World forms. 
 
 Thus all the intimations show that while the mammalian 
 type had already made great advance in the Mesozoic ^Eon 
 almost equally advanced at the beginning and end it was 
 still but meagerly developed. Its affinities, even to the 
 end of the Mesozoic, were with the lower division of mam- 
 mals, the Marsupials. With so little progress between the 
 Triassic and the end of the Cretaceous, we are reminded 
 again, that a long interval of mammalian existence must 
 have passed, before the Triassic Dromaiheriwn took its place in 
 the world. 
 
 With the opening of Csenozoic time all is changed. The 
 transition reminds us of that from the Eozoic to the Palae- 
 ozoic. The world is now astir with mammalian life; and 
 mammalian life has already attained considerable development 
 in rank and diversification of type. When was this advance 
 effected? Probably during the Cretaceous. Then we must 
 ad rait that the sole Cretaceous mammal known fails to represent 
 the average of the Cretaceous. But a glance over the assem- 
 blage of early Tertiary mammals at once shows them stamped 
 with inferior characteristics. They are all greatly generalized 
 that is, some characters of two, three, or more of our modern 
 orders are blended in one individual. This principle is ex- 
 emplified in the early representatives of every group of 
 animals. In the next place, they possessed small brains. If 
 we compare one of them with its nearest relative in any later 
 age, and especially with a modern mammal, the disparity in 
 brain is striking. Enlargement of brain is a strong mark of 
 advancement. Another circumstance is the generally penta- 
 dactyl character of these mammals. To have five toes on each 
 foot may be thought a mark of superiority, since man has 
 five. But five is the typical or fundamental number. This 
 is possessed by many reptiles and by .most of the lowest mam- 
 mals. Advance has been marked by modifications, and these 
 as a fact, have involved, in most cases, a reduction in the 
 number of digits. The extremities of man may, therefore, be 
 
MAMMALIAN RULE. 255 
 
 regarded as more primitive than those of the dog with four 
 digits, the ox, with two digits, and the horse with one. This 
 at least is the prevailing scientific opinion ; but I shall venture 
 presently, to contest it. Finally, most of the early Tertiary 
 mammals were plantigrade ; that is, they walked on the 
 whole length of the foot, with the heel on the ground ; while 
 most mammals walk on the toes with the heel elevated the 
 "hock" being the heel. This also may be thought a mark 
 of superiority, since man is a plantigrade ; but digitigrade 
 walking sustains the same relation as pentadactylism, to pro- 
 gressive advance. 
 
 Is man then, as a five-toed plantigrade lower than the 
 horse, ox, and dog, which are digitigrade with fewer toes ? 
 As a whole, certainly not, since superior brain alone sets him 
 on a pinnacle above them. Is he then inferior in his mem- 
 bral development ? No. Development looks to use, function. 
 Superior development implies more diversified or more dex- 
 trous, functions. Man's limbs compared with any others, 
 show human superiority in a marked degree. What then, is 
 the meaning of the more highly differentiated limbs of most 
 of the mammals? Are we restricted to saying that with act- 
 ually inferior development, they possess superior structures, 
 simply become more highly differentiated structures? That 
 seems to be the prevailing opinion of anatomists. They 
 tell us man's limbs retain the primitive conformation, and they 
 assume that this is an inferior conformation. It is allowable 
 to take the opposite view. Differentiation generally takes an 
 upward course ; but sometimes it takes a downward course. 
 We know a multitude of cases of degenerative differentiation. 
 The paddles and the rudimentary pelvis of the whale ; the flip- 
 pers of the seal ; the rudimentary hind limbs of certain 
 lizards ; the footless condition of other lizards and of snakes ; 
 the eyeless orbits of cavern fishes, are generally regarded as 
 examples of degeneration. If the obsolescence of a whole 
 limb, as in snakes, is a retrogressive differentiation, then why 
 not the partial obsolescence of a limb, as in four-toed and two- 
 toed mammals ? If the high rank of the equine foot is signal- 
 
256 WALKS AND TALKS. 
 
 ized by the possession of one toe, then so is that of the Protop- 
 terus which is absurd. If the high rank of the bovine foot 
 is shown by its didactyl structure, then so is that of the Am- 
 phi-u'ma which is absurd. I hold that man's limb is superior 
 because it has adhered to the primitive type ; it has undergone no 
 degeneration. Because it has adhered structurally to the primi- 
 tive type, it has been capable of its wonderful diversification 
 of function, and admirable subserviency to the ends of high 
 intelligence. 
 
 One of the first figures to greet us on our entering Cseno- 
 zoic times is Co-ryph'-o-don, one of the best examples of a gen- 
 eralized type. As large as a Malayan tapir, with similar short 
 legs, it had no other characters of the tapir, or of other 
 hoofed quadrupeds (Ungulates). It had the full number of 
 the different sorts of teeth; five toes on each foot; nose not 
 adapted for work as in the tapir, hog, and elephant ; canine 
 teeth prominent as in hogs and Carnivores. The feet were 
 somewhat elephant-like, and the head, anterior to the eyes, 
 was long, as in the horse, and the whole range of incisors was 
 horse-like. Here, also was Hy-rach'-y-us, more tapir-like, with 
 four toes in front and three behind. Here further, were two 
 forms more related to the horse, but only as large as a fox 
 Eo-hip'-pm (Dawn-horse) and O-ro-hip'-pus (Mountain-horse). 
 They had four perfect toes in front and three behind ; but in 
 spite of the number of toes, they showed their affinities with 
 the horse in several particulars of structure of the leg and 
 foot-bones and in the teeth. 
 
 A little later, the forms of huge and curious mammals 
 crowd on our view. Til-lo-ihe'-ri-um (Biting-beast) had enor- 
 mous, long incisors, two in number, much like the beaver; 
 but it was not a real Rodent, or gnawer. Di-noc f -e-ras (Fear- 
 ful-horn) was like an elephant in size. It had short legs and 
 perhaps three pairs of horns one on the snout, one on the 
 cheeks, and one on the forehead. These must have given 
 the creature a grotesque and fierce aspect. Its habits appear 
 to have been like those of the Rhinoceros. It was five toed, 
 like Coryph'odon, and in other respects was related widely 
 
MAMMALIAN RULE. 257 
 
 different as it was nevertheless. The Dinoc'eras had for rela- 
 tives U-in-ta-the'rium (Beast of the Uintas) and Ti-noc'e-ras 
 (Avenging-horn). This must have been the ruling family of 
 beasts* during the Eocene, or earlier Tertiary. Only a few 
 mammals related to the fox, wolf, cat, bat, and squirrel had 
 yet appeared on the scene. There was a marked tendency 
 toward the tapir-type, the rhinoceros type, and the horse type. 
 Some even -toed Ungulates came at last Par-a-me' -ryx (Rumi- 
 nant-like) which had relations to camels and stags and were 
 really the precursors of the true Ruminants (Cud-chewers). 
 
 In the Miocene or Middle Tertiary, the tapir, rhinoceros, 
 and horse tendencies continued. The Ruminant tendency 
 also continued. But there was developed, also, a tendency 
 to the hog and the sheep. In fact, the hog and sheep were 
 somewhat united in O-re'-o-don (Mixed-toothed), for which 
 reason Leidy style it " a ruminating hog." Men'-o-dus (strong- 
 tooth) was intermediate between Dinoc'eras and Tapir. 
 It was large as an elephant. Bron-to-the'-ri-um (Thunder- 
 beast) was of similar bulk, and had a pair of horns. 
 Now came, also, the increase of Carnivores. Ma-chcer-o-dus 
 (Saber-tooth) -was as large as a lion, with fearful, tearing 
 canines. Hy-cen'-o-don (Hysena-tooth) was as big as a black 
 bear. Insectivores existed, and now appeared the earliest of 
 the beavers. 
 
 In the Pliocene or late Tertiary, we witness a marked ap- 
 proximation to modern genera. Now the equine type had 
 become almost a horse. Here were camels, rhinoceroses, 
 tapirs. Here the first elephants came upon the scene, though 
 elephantine characters had been in the world through the 
 whole Tertiary. Mastodons were perhaps earlier. The lowest 
 monkeys (Lemurs) had existed from the Eocene; and proper 
 tailed monkeys from the Miocene. But in all this teeming 
 procession of mammals we notice no sign of man save only 
 the prophecy of man. 
 
 22 
 
258 WALKS AND TALKS. 
 
 XL/V. ANTICIPATION AND RETROSPECT IN 
 
 COMPREHENSIVE TYPES. 
 
 WHAT I wish now to set forth is a principle of very pro- 
 found significance. It is a general truth in the nature of the 
 succession of organic types; and I will endeavor to make it 
 plain by citing some of the striking illustrations of it. 
 From the working of this principle, it results that the crea- 
 tures of any age often unite in themselves some characters of 
 a group actually existing, with characters of a group not yet 
 in existence. This is anticipatwn. Such a union forms a 
 "prophetic type," as Agassiz used to express it. It is also a 
 comprehensive type. Also, from the working of this principle, 
 it results that the creatures of any age often unite in them- 
 selves some characters of a group actually existing, with 
 characters of a group which was dominant in a former age 
 whether still existing or not. Such a union forms a retro- 
 spective type. This is also comprehensive. But in some com- 
 prehensive types we find a union of characters none of 
 which belong to any fairly circumscribed existing group. 
 They are all prophetic or anticipatory of groups which are 
 destined to be defined in the future. 
 
 Take first, the early Ganoids for a good example. Their 
 vertebrae were generally concavo-convex. This is a reptilian 
 character. Nearly all reptiles, living and extinct, possess 
 such vertebrae, while all typical or proper fishes possess bi- 
 concave vertebrae. Now the early Ganoids were not reptiles, 
 and had no claim to concavo-convex vertebrae. There had 
 never been a reptile in existence when these Ganoids first 
 lived when 0-nych! -o-dus of Ohio, for instance, flourished. 
 If we may attribute to the ancient Ganoids, certain other 
 characters which belong to modern Ganoids, like the gar- 
 pike, we should say they possessed an opening or glottis in 
 the back part of the mouth, and that a passage existed from 
 this to the air bladder ; and that the latter organ was coarsely 
 
LIFE PLANS. 259 
 
 vesicular, giving a rough imitation of a lung. The gar-pike 
 too, is capable of a vertical motion of the head; that is, un- 
 like all other modern fishes, it has a neck, and can raise the 
 head, like a reptile. The ancient ganoids were certainly not 
 less reptilian than the modern ones. The possession of bony 
 armor is also a reptilian prerogative; and it may be added, 
 that the teeth of the ancient ganoids were truly reptilian. 
 Those of Onychodus were strikingly so. As in reptiles, too, 
 the vertebral column continued to the end of the tail. Thus 
 the ancient Ganoids possessed several reptilian characters; 
 while in general form, they were fish-like; in aquatic respira- 
 tion, in many rayed fins, in cranial and general skeletal struc- 
 ture they were fishes. Thus the ancient Ganoids, and to a 
 similar extent, the modern ones, were a comprehensive type. 
 They anticipated reptiles ; they were prophetic of reptiles. 
 Later the ganoid type was resolved. The ichthyic characters 
 were retained in one organism, and the reptilian were gathered 
 together in a different organism. Now, we can not avoid 
 feeling interest in the question: How did it occur that an 
 animal on the whole a fish, should incorporate in its structure, 
 features of a class which was yet far in the future? And 
 what was the purpose of such a combination ? I will try to 
 express my views on these questions when I come to a Talk 
 on the method of creation. 
 
 The Amphibians are a comprehensive type. They are 
 comprehensive as a whole as a class-conception ; and within 
 the class are subordinate or ordinal types which are specially 
 comprehensive. Structurally they partake of the natures of 
 fishes and of reptiles. They are fish-like in branchial respir- 
 ation during early life. They are fish-like in the possession 
 of bi-concave vertebrae; in having two occipital condyls, and 
 in other less conspicuous characters of the skull ; in the organs 
 which serve as kidneys; and among Batrachians (frog-like) 
 in the double septum which divides the orbits which is a 
 ganoid character. They are reptilian in breathing air in adult 
 life ; in the possession of appendages for locomotion on land, 
 and in the undivided ventricle of the heart. The nervous 
 
260 WALKS AND TALKS. 
 
 system is intermediate between fishes and reptiles. The ex- 
 tinct Labyrinthodont, while possessing many distinct batra- 
 chian affinities, was reptilian in its crocodile-like skull, and 
 the protective bony plates upon the thorax and flanks. In 
 the teeth is found, however, the peculiar labyrinthine struc- 
 ture seen in some Placoderm fishes; and the sculptured plates 
 of the Ganocephala furnish a resemblance to bony scaled Gan- 
 oids. The structure of Amphibians is on the whole, so rep- 
 tilian that they were, for many years, merged in the reptile- 
 class. Now Amphibians existed, as far as we know, before 
 the reptile-type had been introduced. All their reptilian 
 characters therefore, were prophetic of a class which was yet 
 non-existent. On the contrary, they appeared when the reign 
 of fishes was passing away. All their ichthyic characters, 
 therefore, were retrospective. 
 
 Take next, the wide-ranging class of Reptiles. During the 
 age of its dominance, various ordinal divisions exemplified 
 various relations to the future and the past. While the 
 concavo-convex vertebra was proper to reptiles, the sea-saurians 
 had bi-concave vertebrae a reminiscence of fishes. Other 
 reptiles had the teeth soldered to the jaws as in fishes. Some rep- 
 tiles with socketed teeth, however, had bi-concave vertebrae. The 
 Ichthyosaurs, with fish-like vertebrae and jaws, had crocodilian 
 teeth and whale-like paddles. It looked forward toward the mam- 
 malian type. Some of the Deinosaurs, also, were prophetic 
 of land-mammals in their short, compact bodies, while their 
 bi pedal attitude anticipated both mammals and birds. A more 
 explicit anticipation of birds was revealed in the composition 
 of the digits and the structures of the tarsus and pelvis. The 
 Pterosaurs were prophetic of bats in their leathery wings sup- 
 ported by elongated digits. They foreshadowed birds, not alone 
 in the flying function, but in their bird-like scapula, coracoid, 
 and other structures. In one genus the tips of the mandibles 
 were without teeth ; and in the American Pterosaurs, the mandi- 
 bles were completely destitute of teeth, while the tail also, is re- 
 duced to a few vertebrae, and the head is distinctly bird-like. 
 
 The gradation of reptiles towards birds brings us to facts 
 
LIFE PLANS. 261 
 
 still more remarkable. In the Jurassic slates of Solenhofen 
 in Bavaria, which have yielded specimens of Pterodactyls re- 
 taining the impression of the leathery wing, have been found, 
 also, remains of a bird which had a long vertebrated tail, like 
 a lizard, with a pair of quills standing out from each vertebra. 
 It had also, saurian teeth inserted in sockets. It had a true 
 bird-foot, except that the metacarpals were separate. This 
 wonderful compound of bird and reptile, after causing much 
 discussion, was finally assigned a place among birds and named 
 Ar-chce-op'-ter-yx or " old-flyer." Very recently, however, other 
 specimens have been found, and Carl Vogt of Geneva, after 
 careful examination, declares that the creature was a feathered 
 lizard, and not a bird. There are two conical teeth in the 
 upper jaw ; eight neck- vertebrae, with five pairs of ribs directed 
 backwards ; ten dorsal vertebrae without spiuous processes, and 
 supporting ribs without uncinate processes ; five sternal ribs 
 and very minute sternum. The fore-limb, he maintains, is 
 not a proper wing, and there are three digits resembling those 
 of a clawed lizard ; the feathers are attached to the side of 
 the arm, hand, body, legs, and tail. If the feathers had not 
 been preserved, no one would have thought this Old-flyer a 
 bird, or capable of flight. Now what can we say of a crea- 
 ture having the bird and reptile so mixed that the best judges 
 are unable to decide whether it is one or the other ? We can 
 pronounce it, at least, a comprehensive type, and receive it 
 as throwing some light on the method of organic history. 
 
 The Cretaceous Age in America produced still other mon- 
 grel forms, which have been published to the world by Pro- 
 fessor Marsh. These seem to lean unmistakably toward the 
 side of birds; but they possessed saurian teeth, and are known 
 as O-dont-or'-ni-thes or ''Toothed-birds." There are two genera. 
 leh-thy-or'-nis or "Fish-bird," had strong wings, bi-concave (fish- 
 like) vertebrae, and teeth inserted in sockets. Hes-per-or'-nis 
 or "Western-bird" had feeble wings, and teeth inserted in 
 grooves along the crests of the jaws. 
 
 From such examples as have been cited, it will be under- 
 stood that the principle of comprehensive types results in 
 
262 WALKS AND TALKS. 
 
 gradational relations. That is, organic forms, recent or fossil, 
 may be arranged in series according to structural relationships. 
 The forms more or less bird-like, for instance, may be ranged 
 in a column beginning with most highly developed birds, and 
 ending with characteristic saurians. We find, indeed, two 
 series, and may arrange them as follows: 
 
 I. FROM RUNNING-BIRDS BACK TO REPTILES. 
 
 1. Struthious Birds, ostrich-like, feeble wings, runners. 
 
 2. Brontozo'iim, bipedal, three toed, with phalanges bird-like. 
 
 3. Laosau'rus, bird-like in head, ischiac and post-pubic bones and 
 
 toes. 
 
 4. Compsog'nathus, bird-like in head, consolidated astragalus and 
 
 tibia. 
 
 5. Anomce'pus, four toes before, three bird-like toes behind. 
 
 6. Hadrosau'rus, weak fore-legs, attitude bipedal. 
 
 7. Rhynchosau'rus, saurian with toothless mandibles, bipedal. 
 
 8. Iguan'odon, tips of premaxillaries toothless, obliquely bipedal. 
 
 II. FROM CARINATE BIRDS BACK TO REPTILES. 
 
 1. Carinate Birds, sternum keeled, flying birds. 
 
 2. Hesperor'nis, with poor wings, teeth in grooves. 
 
 3. Ichthyor'nis, with good wings, socketed teeth, biconcave ver- 
 
 tebrae. 
 
 4. Archseop'teryx, bird or lizard, tail long, teeth socketed, metacar- 
 
 pals separate. 
 
 5. Pteran'odon, winged reptile, short tail, no teeth, bird-like head. 
 
 6. Ramphorhyn' chus, winged reptile, distant, sharp and curved teeth, 
 
 horny tips of mandibles, long tail. 
 
 7. Pterodac'tylus, winged reptile, bird-like scapula and coracoid. 
 
 8. Thecfodont Saurians, typical saurians with socketed teeth. 
 
 Here are two lines of gradation from reptiles to birds, 
 arranged out of extinct forms. It must be stated, however, 
 that their order of succession in time does not correspond with 
 their relative position in the gradation. But we know, as yet, 
 so little about the complete fauna of different ages, that it 
 would be rash to conclude that the actual order of appearance 
 was not accordant with their order in rank. 
 
 Let me now present a gradation of forms which corre- 
 sponds strictly with their order of appearance. 
 
LIFE PLANS. 263 
 
 1. Equus, late Pliocene. Common horse, feet reduced to central series 
 
 of bones (middle finger and toe), a pair of ''splints" to rep- 
 resent second and fourth digits. 
 
 2. Pliohip'puS) middle Pliocene. Smaller, central digital series more 
 
 slender; splints more elongated; crown of upper molars 
 shorter, and crescentic areas simpler. 
 
 3. Protohip'pus, early Pliocene. Size of Ass; central digital series 
 
 still more slender ; splints terminated by dangling hooflets ; 
 ulna long as arm, but slender; fibula rudimentary; crowns of 
 molars much shorter. 
 
 4. Miohip'pus, of late Miocene. Size of sheep ; three functional toes 
 
 before and three behind; small splint of fifth digit, before; 
 ulna distinct, long as radius, but very slender at lower end; 
 fibula co-ossified with tibia at lower end; molar crowns de- 
 cidedly short ; enamel folds much simpler than in horse. 
 
 5. Mesohip'pus, of oldest Miocene. Size of sheep ; three functional 
 
 toes before and three behind, but more nearly equal than in 
 Miohippus ; large splint of fifth digit, before ; radius and ulna 
 distinct, and also tibia and fibula. 
 
 6. Orohip'pus, of middle Eocene, of Wyoming and Utah. Size of 
 
 fox ; four functional toes before and three behind ; ulna com- 
 plete and distinct from radius; tibia and fibula also distinct; 
 molar crowns exceedingly short; enamel pattern simple. 
 
 7. Eohip'pus, of oldest Eocene, of New Mexico. Size of fox ; four 
 
 functional toes before and three behind ; rudiments of outer 
 or fifth toe behind, and hence, probably, of first digit before ; 
 hoofs mere thick, broad and blunt claws; molars less spe- 
 cialized than in Orohippus, without cement. 
 
 The affinities, gradations, and successions thus indicated are 
 facts of observation ; they depend on no theory of organic 
 history. They simply show that each type of the past pos- 
 sessed characters which related it to organisms yet future. 
 There was retrospect; there was anticipation. The past was 
 bound to the present; the present, to the future. History 
 was a constant unfolding of that which was contained in the 
 past. Progress was a perpetual fulfillment of prophecy. 
 
264 WALKS AND TALKS. 
 
 XL/VI. THE THROES OR THE CONTINENT. 
 
 HOW THE LAND GREW. 
 
 WHILE the great plan of organic life was unfolding itself, 
 the continental theater of its exhibition underwent a process 
 of expansion which no less reveals a plan, and no less awakens 
 our interest and admiration. By what stages the region east 
 of the Great Plains acquired its form and dimensions, has 
 long been understood ; but the method of the building of the 
 western half has only been Jbrought to light through the re- 
 cent researches of Hayden and Meek, King and Wheeler, 
 Powell and Dutton, Gilbert and Hague, Whitney and Gabb, 
 and their compeers and collaborators. 
 
 East of the Great Plains, rose first a long, hook-shaped 
 ridge, with its longer branch stretching from the north shores 
 of the Upper Lakes to the Arctic Ocean, in the region be- 
 tween Hudson's Bay and McKenzie's River; while the shorter 
 branch extended northeastward as far as the coast of Labrador. 
 Not improbably this branch stretched across the North At- 
 lantic to the British Islands and Scandinavia. This primitive 
 area I have styled the Great Northern Land. It is also known 
 as the Laurentian area a name which applies properly only 
 to the portion sustaining some contiguity to the St. Lawrence. 
 
 Along the low seaboard region east of the Appalachians, 
 stretches, from Maine to Alabama, the stump of an ancient 
 mountain range which appears to have been of the same age. 
 The stump only, I say, for the tooth of time has gnawed it 
 nearly level with the sea, and the old material has been re- 
 built in the foundations of later lands. This was the great 
 Seaboard Land. 
 
 West of the Great Plains, as we now understand, stretched 
 another long belt of land, which was destined eventually, to 
 be consolidated with the eastern lands, to form the continent. 
 In width, it extended originally that is, at the beginning 
 of the Palaeozoic JEon, from the eastern bases of the Rocky 
 Mountains to western Nevada probably seven hundred and 
 fifty miles; in length, it stretched far northward and south- 
 
THE THROES OF THE CONTINENT. 265 
 
 ward, to distances not yet ascertained. This was the Great 
 Cordilleran Land. There were probably other small land 
 areas, rising like islands from the universal ocean; and there 
 may have been other areas of moderate continental extent; 
 but, so far as our probable knowledge goes, the three con- 
 tinental expanses mentioned were the chief beginnings of North 
 America. 
 
 Simultaneously some of the north-eastern portion of South 
 America was land; and perhaps, also, a part of the region 
 now occupied by the West Indies. Some portions of the 
 British Islands were also land ; and this stretched across the 
 North Sea into Scandinavia. Most other parts of the world 
 were sea-bottom. 
 
 The Cordilleran Land was a great mountain system, dis- 
 playing lofty ranges made of crumpled strata ; enormous prec- 
 ipices, the result of mechanical dislocation; and finally, a 
 type of mountain sculpture, of such broad, smooth forms as 
 to warrant the belief that subaerial erosion had never carved 
 and furrowed the mountain flanks with the sharp ravines 
 characteristic of modern mountain topography. This massive 
 belt of Eozoic Cordilleras determined the limits of the mod- 
 ern cordilleras, and very much of the details of their funda- 
 mental structure. 
 
 Such was America in the twilight of its history. There 
 must have been, however, as I have argued in Talk XXXEK, 
 some lands which had now disappeared. These surviving 
 germinal nuclei are composed of stratified rocks. Older rocks 
 had been reduced to sediment in supplying material for the 
 building of the lands which are the oldest now remaining. 
 Let us see what vicissitudes these lands were destined to un- 
 dergo. 
 
 The first aeon of the ocean's history was past. With the 
 opening of the second, nearly the whole of the Cordilleran 
 Land began to subside. It sank until only the mountain 
 masses rose as rugged islands above the sea-level. Only the 
 western border held its position. This remnant of the Cor- 
 dilleran Land stretched along western Nevada and eastern 
 
 23 
 
266 WALKS AND TALKS. 
 
 California. The continent eastward became an archipelago. 
 Cambrian sediments were deposited over all its scarred and 
 broken surface. One ocean stretched from western Nevada 
 to New England. Whether the Atlantic Seaboard Land rose 
 or subsided, we are unable to say. Probably it sank, and its 
 original extent became concealed by overlapping Cambrian 
 sediments. The Great Northern Land, however, began a slow 
 upward movement, which was destined to continue through 
 all Palaeozoic time. 
 
 In the progress of the Palaeozoic ages, the tenor of conti- 
 nental history was an almost continuous emergence of the 
 Laurentian portion of the Northern Land, and a continuous 
 sinking of the Cordilleran Land. The Laurentian, accord- 
 ingly, continued to broaden its base as the remnants of the 
 Cordilleran continued to grow less. The Cordilleran sub- 
 sidence was greatest toward the shore of the Nevada conti- 
 nent, which was undergoing vast wastage in supplying the 
 sediments which overspread the surface of the sunken Cordil- 
 leran region. Coarse and thick toward the west, they became 
 finer and thinner eastward. By the close of Palaeozoic time, 
 the sediments accumulated over the Cordilleran Land were 
 one thousand feet thick in the Kocky Mountains, thirty-two 
 thousand feet in the Wahsatch region, and forty thousand 
 feet at the extreme western Palaeozoic limit, longitude 117 
 3(X west. Only a few granitic islands interrupted the con- 
 tinuity of the uppermost Carboniferous sheets, from Nevada 
 to the Great Plains. The ancient Eozoic topography was 
 buried irretrievably out of sight save where, in later times, 
 local uplifts brought it again up to observation. The Appa- 
 lachian region, meanwhile, underwent a similar subsidence. 
 There are some reasons for supposing this region was, at the 
 beginning of Palaeozoic time, annexed to the western border 
 of the Seaboard land. If so, the conditious here were a sink- 
 ing land loaded with sediments derived from a wasting stationary 
 land on the east; as in the west, the situation was the same, but 
 with the wasting land on the west. West and east the fixed 
 and wasting land was oceanward from the sinking area. 
 
THE THROES OF THE CONTINENT. 267 
 
 Great changes now took place. The Nevada continent, 
 which had yielded thousands of cubic miles of Palaeozoic 
 sediments, now, in its turn, went down, and a broad region 
 eastward, as far as the Wahsatch Mountains, came up. The 
 Cordilleran continent was now located in the region at present 
 known as the "Basin Province," embracing Great Salt Lake, 
 Pyramid Lake, and others. Only the foundations of the 
 Sierra Nevada had been laid. The Basin Continent on the 
 east was to be ground up to supply the masonry for a new 
 structure ; just as the Nevadan foundation itself was the 
 mere stump of a land pulverized to supply materials for 
 the Basin Land. So nature's method is to build, demolish, 
 and rebuild. As in the successions of life, so in the succes- 
 sions of continents. 
 
 But while this continental see-saw was in progress west of 
 the Wahsatch, all remained quiet to the east, as far as the 
 Great Plains. In the Appalachian region, however, a similar 
 see-saw occurred. The loaded Appalachian belt came up in a 
 series of mountain folds fifteen thousand feet high, while the 
 Seaboard Land, that had been wasted in supplying the load, 
 went down most of it, like the old Nevadan continent, below 
 sea-level. Simultaneously, the whole breadth of the country 
 westward to the Great Plains, was finally annexed to the 
 eartern limb of North America. 
 
 It was now the beginning of the geologic Middle Ages. 
 East of western Kansas, the land was completed, save the 
 Atlantic and Gulf border. . West of the same meridian 
 stretched a broad ocean over the region of the Great Plains ; 
 across the belt of the Rocky Mountains, where it was inter- 
 rupted by the meridionally disposed Colorado, Medicine Bow, 
 and Park Ranges ; across the broad Plateau region of the pres- 
 ent, to the base of the newly uplifted Basin Land which was 
 now melting away under the sedimentary demands for Meso- 
 zoic materials on the east and the west. To the south, this 
 ocean extended to the Gulf of Mexico. Northward, it joined 
 the Arctic Ocean. West of the Basin continent, the sedi- 
 ments of the Triassic and Jurassic formations were laid down 
 
268 WALKS AND TALKS. 
 
 uncouformably on the eroded Eozoic surface which had sunken. 
 East of the basin continent, the new sediments were spread 
 conformably on the last Carboniferous sheets. At the close 
 of the Jurassic Age, these sediments had attained on the west, 
 a thickness of twenty thousand feet. On the east, they were 
 less than four thousand feet. 
 
 Now rose the vast crumpled folds of the Sierra Nevada, 
 adding two hundred miles to the Basin continent on the west, 
 and stretching southward at least to the thirty-sixth parallel, 
 and northward to Alaska. East of the Wahsatch, however, 
 every thing still remained quiet save that the great orographic 
 event of the west sent its rock-fragments, pebbles and sands 
 eastward over the ocean's floor as far as Kansas, forming the 
 conglomeritic Dakota Group at the base of the Cretaceous. 
 
 No further orographic disturbances took place until the 
 close of the Cretaceous. To this epoch, the sedimentary sheets 
 had been laid down in conformable positions continuously 
 from the Cambrian upward. Now, however, came the turn 
 of the region at present known as the "Plateau Province." 
 Upward and undulatory movements were experienced from 
 the region of the Great Plains to the base of the Wahsatch. 
 Now rose the broad, flat, east-and-west anticlinal known as 
 the Uinta Mountains ; and the whole mass on the east was 
 further upraised, of which the rocky Mountains are the salient 
 ridges. The broad shallow basin of the Colorado River was 
 now defined. On the Pacific coast, this disturbance was felt 
 only in the defining of the position of the Coast Ranges. 
 
 The great feature of this post-Cretaceous movement was 
 the re-emergence of that part of the ancient Cordilleran area, 
 now called the Plateau Province. It had sunken, with the 
 whole breadth of the Cordilleran Land, at the end of the 
 Eozoic JEon. Now the two limbs of the American continent 
 were joined together. From Middle California to Boston Bay 
 was a continuous land connection. Only a narrow border re- 
 mained to be added around the Atlantic, Pacific, and Gulf 
 coasts. Remnants, however, of the ancient mediterranean sea 
 remained in the interior, forming lakes as large as Superior. 
 
THE THROES OF THE CONTINENT. 269 
 
 These, in the succeeding ages, were at times enlarged, at 
 times contracted, through the orographic movements taking 
 place, and finally filled or drained (see Talks XVIII and 
 XLIV). During the Miocene epoch a great lake covered the 
 region of the Great Plains, as far as the Gulf of Mexico a 
 region which appears to have been mostly land during the 
 Eocene. Meantime, vast volcanic eruptions were taking place 
 along the Pacific border, burying thousands of square miles 
 under lava, and supplying ashes which filled some of the 
 western lakes four thousand feet deep. 
 
 The interior lake history continued of similar tenor till the 
 close of the Pliocene, when the grand movements occurred 
 which impressed on the broad Cordilleran region its present 
 surface features. The rocky sheets of the Great Plains were 
 tilted into a position which secured drainage of the great lake 
 which had covered them. In the far west, the Sierra Nevada 
 and the Wahsatch were rent logitudinally by great faults 
 along their crests, and the continental mass between the faults 
 sank down one or two thousand feet, forming the Great Basin, 
 and returning it to the depressed condition which it had held 
 through the whole of Palaeozoic time. On its eastern and 
 western borders, gathered two lakes, each as large as Huron, 
 the eastern of which has shrunken to Great Salt Lake, Utah, 
 and Sevier; while the western exists only in the remnants 
 known as Pyramid, Winnemuca, Carson, Walker, and Hum- 
 boldt Lakes. Later mountain ranges have risen here and 
 there in the Basin, and volcanic outbursts have contributed to 
 diversify the topography. These final disturbances, followed 
 probably by some later ones all embraced within the Quater- 
 nary period shattered the Plateau Province to a destructive 
 extent. Great fractures ran through it from end to end. On 
 one side of each, the rocky sheet is generally upraised, and 
 on the other, depressed. Volcanic mountains have been built 
 up here and there, and earthquakes have shattered the blocks 
 shaped by the meridional faults. Simultaneously, surface ero- 
 sions have perpetually changed the configuration of the surface. 
 Rivers have cut their way through mountains, through lava 
 
270 WALKS AND TALKS. 
 
 plains, through the later strata, and in some cases, a thousand 
 feet into the long-buried formations of the primitive Cordil- 
 leran Land. 
 
 . THE R.EIQN OF ICE. 
 CONTINENTAL GLACIATION. 
 
 THE gradual enlargement of the continent had brought it 
 now to the condition in which man was destined to make its 
 acquaintance. The gradual advancement of organic improve- 
 ment had now reached a stage where the next step must 
 bring man upon the theater of life. Even the animals which 
 man was destined to domesticate were already on the earth, 
 and awaiting the advent of their master. The forests too, 
 had assumed the aspect which was to become familiar to man, 
 and seemed to stand expectant of the being so long promised. 
 The whole earth seemed ready for that final stroke which 
 should consummate organic improvement, justify the physical 
 preparations through aeons in progress, and explain nature's 
 long-continued appeals to intelligence and taste which had not 
 been in the world. 
 
 But nature must yet pause. The continents intended for 
 civilized man lacked something yet to fit them for his advent. 
 Throughout Asia, Europe and North America, the continental 
 surface had become deteriorated by erosions and wastage tak- 
 ing place during the reign of mammals. The land had been 
 set apart for the use and convenience of this dynasty, and in 
 their service it had been exhausted. Each of the great domi- 
 nant dynasties in succession, had the continents for their use, 
 and in their behoof they were worn ont. For each new dy- 
 nasty a renovation was demanded. At the present juncture, 
 the soils had been reduced through wastage, to the condition 
 which we plainly see approaching again under the actions ex- 
 .erted during the human reign. The rivers, long confined to 
 the same channels, had excavated deep gorges. Retired in 
 these their evaporation was checked, the clouds were starved 
 and the soils were robbed of their rains. Every tributary 
 
THE REIGN OF ICE. 271 
 
 had scored a ravine which split the land. The streams were 
 inaccessible and dwarfed, and their availability for human 
 uses seriously impaired. There must be a general repair of 
 the surface before it would meet the demands of a being of 
 such enterprise and resources as man was destined to be. 
 
 The end so necessary was accomplished without departure 
 from the fundamental method of all the previous history of 
 the continents. Uplift and subsidence accomplished the gla- 
 cial renovation which now approached. We have already 
 studied many indications of glacier action. We have con- 
 cluded (Talk III, which should now be reviewed) from the 
 inductive evidence, that a continental glacier has some time, 
 brooded over the land, and we have made some observa- 
 tions on actual glaciers (Talk IV). We will now attempt to 
 sketch the glaciatiou of a continent, from a historical point 
 of view. 
 
 The mild climate of the middle and later Tertiary time 
 which had prevailed as far north as Disco, on the coast of 
 Greenland, and Melville and Bennett Islands in the Arctic 
 Ocean, had already been succeeded by a colder one. The cause 
 of the change remains an unsolved problem. The later invasion 
 of severe cold, throughout the northern temperate zone, is 
 generally ascribed to northern elevation; but there is much 
 reason to suppose it the result of certain astronomical changes, 
 and to hold, also, that this was but one of a succession of glacial 
 visitations. Whatever the cause, the reality of the glacier period 
 can not be questioned. The area of perpetual snow had ex- 
 tended its limits from the arctic zone into northern America. 
 In the middle latitudes, an unwonted chill was already ex- 
 perienced in the atmosphere. Successive winters grew more 
 and more severe, and the snow lingered always later in the 
 spring. There were deep ravines where it survived the sum- 
 mer. With continued depression of mean temperature, the 
 winter snows still further delayed their departure. The forest 
 was changed. One by one, the species suited to a milder cli- 
 mate perished ; and frost began to brown foliage in a zone 
 which had witnessed a state of perpetual verdure. Year by 
 
272 WALKS AND TALKS. 
 
 year, the line of permanent snow extended itself southward. 
 Probably the volume of snowy precipitation was increased, 
 and thus the march of the reign of snow, was accelerated. 
 
 The sheet of perpetual snow, to whatever limit it reached, 
 was divided into two areas by an isothermal line. Had the sun 
 never exerted a thawing influence had no thawing ever 
 taken place in any portion of the snow, it would have re- 
 mained a soft and fleecy covering. But wherever incipient 
 thawing was felt, the snow crystals began to resolve them- 
 selves into grains of ice. Down to the latitude where this 
 change was unable to proceed farther, the condition of the 
 snow remained granular, as it now does in the Alps. If how- 
 ever, the melting influence proceeded farther, the granular 
 snow-mass resolved itself into solid ice. These changes can be 
 traced in the snow which falls upon our streets. Thus all the 
 southern portion of the snow-field became a true glacier; 
 north of that was a zone of neve ; and possibly a zone of soft 
 snow covered the area still nearer the pole. All this, of 
 course, supposes precipitation to have taken place. If in any 
 region, precipitation was wanting or scant, the snowy or icy 
 covering did not appear. 
 
 On its northern border, the glacier was fixed to the mass 
 of ice or neve beyond ; and very probably it was fixed to the 
 earth. The glacier, like all glaciers, must move; and the 
 motion would be developed along the free border. The 
 glacier, therefore, traveled southward. Consider the conse- 
 quences of the motion. The soft snow had filled the gorges 
 and the river valleys. It had settled around cliff and crag, 
 and when it became ice, it held them in its firm grasp. The 
 motion of the glacier wrenched fragments from their fasten- 
 ings and moved them southward. The rock fragments, like 
 diamonds in a setting, marked and scored the underlying sur- 
 face. The loose materials, the accumulation of a previous 
 geologic aBon, were plowed to the bed-rock. The bed-rock 
 was scored and striated by the tremendous power of the 
 glacier. 
 
 Every year, the great ice-sheet encroached a little farther 
 
THE REIGN OF ICE. 273 
 
 on the unglaciated area. This resulted partly from the south- 
 ward growth of the glacier, and partly from its southward 
 motion. In its motion, it prostrated the standing forest, and 
 the ruins were mingled with the rock-ruin which the ice-mass 
 stirred and transported. The march of the glacier's southern 
 border continued until it reached New York, Louisville, St. 
 Louis, and Topeka. It passed over Long Island Sound and 
 reached the ocean shore. Westward, over the Great Plains, 
 its footmarks are not traced. Perhaps the precipitation there, 
 as now, was insufficient to enable the snow to outlast the sum- 
 mer heat. Further west, the glaciation seems to have been 
 restricted to mountain ranges. But glaciation was far from 
 unknown, even to the Pacific slope. Northward, the extent 
 of the glaciation increased, as far as Alaska. 
 
 Now the geologic winter was marked by an "'open" spell. 
 It probably lasted for centuries. The ice dissolved, and the 
 border of the glacier retreated perhaps, to the latitude of 
 Marquette. Over the uncovered area, it was a new spring- 
 time. Vegetation sprang into existence, and a fresh soil 
 accumulated. Then came a recurrence of cold. The old 
 glacier resumed its southward movement. In saying it was a 
 "continental" glacier, it is not meant that an ice-field conti- 
 nent-wide moved with a consentaneous movement. The ice- 
 sheet felt the influence of the underlying topography. Its 
 motion tended everywhere to the lower level and warmer 
 situation. Seldom was that direction precisely south. In the 
 valley of the Connecticut, the movement was south. In the 
 valley of the Mohawk it was eastward. Through the valley 
 now occupied by Lakes Ontario and Erie, it was south-west 
 as far as Indianapolis, and south as far as Columbus. Another 
 glacier stream flowed through the valley destined to be the 
 basins of Lake Huron and Saginaw Bay. Its southern border 
 joined the Lake Erie glacier ; and the long broken chain of 
 sand and bowlder hills passing through Ann Arbor, shows 
 where the joint rubbish of the two glaciers was left. Another 
 glacier stream passed along the valley of Lake Michigan; 
 another down the valley of Green Bay and its continuation to 
 
274 WALKS AND TALKS. 
 
 Madison. Still others streamed from Keweenaw Point and 
 Duluth into central Wisconsin and Minnesota. Wherever 
 these local ice-streams terminated, they left moraines to mark 
 the extent of their advance. This was the "second glacial 
 period." The entire continent north of an irregular line pass- 
 ing through New York, Fort Wayne, Madison, Minneapolis, 
 and Yankton, lay, like the soil of Greenland in our time, 
 buried beneath a bed of ice and snow some thousands of feet 
 thick. The summits of the Adirondacks, the Catskills, and 
 the White Mountains barely emerged above the desolate, 
 featureless waste. What went on how the subglacial ine- 
 qualities of surface strained the semi-rigid ice-stream into con- 
 formity ; how the deep ice-mass snapped with loud detonations, 
 into yawning crevasses; how the summer sun gave origin to 
 superglacial streams Avhich sooner or later lost themselves in 
 the fissures, and joined the roaring streams beneath the ice, 
 which escaped at intervals along the southern border ; how 
 they were augmented by the enormous thawing of the under 
 surface of the glacier; how these streams assorted and trans- 
 ported the subglacial debris all these things are of too great 
 interest to fail of mention, but of too great importance to admit 
 of adequate discussion. 
 
 During this reign of ice, the snows fell which overtook the 
 long-haired elephant of Siberia and Alaska (Talk XXVII), 
 and buried them in herds. They had been browsing for 
 many generations on that northern slope. I know not to how 
 severe a climate their natures fitted them ; but clearly it had 
 not been a climate which brought perpetual snow. Now they 
 experienced a new chill in the atmosphere. Now the snows 
 descended and they crowded themselves together in ravines 
 for warmth and mutual protection. Their instincts taught 
 them this mode of self-preservation. They had often outlived 
 a snow-burial during winters preceding. But their last burial 
 finally arrived. Now no thaw succeeded the overwhelming 
 storm. No spring-time returned to release them from their 
 chilly retreat. Spring only turned the snowy blanket to ice. 
 Other winters buried the mammoth beneath added beds of ice. 
 
A GEOLOGIC SPRING TIME. 275 
 
 In such a tomb, they lay unchanged until the age of man 
 and slowly returning warmth brought their lifeless carcasses 
 to a dumb resurrection. 
 
 The accumulation of five thousand feet of ice over a por- 
 tion of the earth's surface required some new adjustments of 
 equilibrium. If the ice-bed covered the entire north, and the 
 terrestrial crust remained rigid, the added weight transferred 
 the earth's center of gravity toward the north, and with it 
 flowed the ocean northward. With a flooding of all the 
 northern shores there was a corresponding emergence of the 
 antarctic. If the weight of ice depressed the terrestrial crust, 
 the position of the center of gravity may not have been 
 changed; but the shores depressed would be flooded by the 
 ocean, as before. Farther, the displaced fluid matter beneath 
 sought escape, through fissures, to the surface. If the enor- 
 mous ice-pressure was felt by the regions east of the Great 
 Plains and north of the Snake Kiver, the depression of the 
 glaciated regions caused the fluid internal substances to react 
 beneath regions farther west and south ; and in many cases, to 
 develop fractures through which molten outflows took place. 
 In this view, the great post-pliocene lava floods of the west 
 were the counterpart of the great ice-burdens of the east and 
 north. 
 
 . A. GEOLOGIC SPRING 
 
 INCIDENTS OF THE CHAMPLAIN EPOCH. 
 
 THE rigor of the long winter began to relent. We can not 
 certainly state what physical conditions brought about the 
 change ; but if elevation brought the cold, then probably, the 
 return of warmth resulted from restoring the ancient level. 
 We are certain, on good evidence, that a subsidence took place. 
 At some time after the advent of general glaciation, the east- 
 ern United States and Canada were inundated by the ocean. 
 The depth of the submergence was 470 feet at Montreal ; 
 and it diminished gradually southward. At Lewiston, Maine, 
 the sea-beach is two hundred feet above present tide-level ; 
 
27G WALKS AND TALKS. 
 
 near Boston, one hundred feet ; on Nantucket, eighty-five feet. 
 Northward, on the contrary, the submergence increased in 
 depth. On the coast of Labrador, it was five hundred feet ; 
 in Barrows' Strait, it was over one thousand feet. The usual 
 opinion is that this submergence occurred after the dissolution 
 of the glacier; but I incline to the conviction that it was 
 coincident with the glacier. I have already suggested, follow- 
 ing Croll and general opinion, that a load of northern ice 
 would very probably cause submergence of northern shores 
 though I think it resulted from depression of the crust, rather 
 than a shifting of the center of gravity. Such submergence 
 would be greatest northward. The facts observed seem to 
 show that it was a submergence of the glacial epoch, instead 
 of the post-glacial. If the sunken shores were already buried 
 in ice, the temperature of the sea would dissolve it, and the 
 sea-bottom would be of the usual character of a submerged 
 beach. 
 
 The depths of submergence just mentioned are far less than 
 would have taken place, if the crust of earth had yielded 
 readily to the pressure of five thousand feet of ice. To have 
 influenced the temperature, there must have been a much 
 greater subsidence from the point of maximum elevation. It 
 is reasonable to conclude that the action which caused the 
 original elevation was now reversed, and much greater subsi- 
 dence took place than was due to the load of ice. 
 
 Whatever the amount of subsidence; whatever its cause; 
 whatever the cause of the climatic amelioration, there is no 
 question about the return of a geological spring. The glacier 
 began to waste more than its annual growth. A steady re- 
 cession began along its southern margin. A series of morainic 
 loops was left to mark its farthest advance. They were com- 
 posed of bowlders and sand. The materials were accumulated 
 in hills and ridges, with intervening "pot-holes" and valleys. 
 The dissolution of the ice-field proceeded with rapidity. Lively 
 rills flowed over the surface of the ice, and turbid streams 
 sprang from the foot of the glacier such streams as make the 
 Aar (Talk VIII) and the Arve (Talk IV). The moraine de- 
 
A GEOLOGIC SPKING TIME. 277 
 
 posits were partially washed away. The moraine of the first 
 glacial epoch, farther south, was now subjected to the action 
 of a second flood. It suffered greater erosion than the second 
 moraine, and hence remains to us a less conspicuous feature 
 than the second. 
 
 The ice-sheet had laid down an unstratified bed of "till" 
 a compact mass of clay, pebbles, and bowlders; the glacial 
 flood transported vast quantities of material, and left them in 
 a state of torrential stratification overspreading the till. There 
 is much reason to believe that the materials thus transported 
 were borne beyond the limits reached by the glacier. In 
 this way, the action of the glacial expedient for renovating 
 the surface of the north was extended to the southern states. 
 There has certainly been a southward transportation of peb- 
 bles and sand throughout all the Gulf states. It was an event 
 synchronous with the dissolution of the great glacier. But 
 we must bear in mind that the south had not been visited by 
 an agency which plowed up the disintegrated rocks accumu- 
 lated during preglacial ages. The flooding of the south ex- 
 erted only a surface action. 
 
 Between the glacier and the floods, the surface of the 
 whole country east of the Great Plains with the exception 
 of a few small isolated areas underwent a process of thorough 
 repair. The sharp river gorges were filled even an ancient 
 gorge of the Niagara Kiver and a fresh bed of subsoil mate- 
 rials was spread over the land. The larger rivers sought out 
 the drainage valleys which they had occupied before the in- 
 vasion of glaciers. The fundamental features of the drainage 
 were everywhere determined by the underlying rocky struc- 
 ture. But many of the smaller streams which now sprang 
 into existence, selected for the first time their winding chan- 
 nels among the inequalities of the Drift-covered surface. From 
 that epoch to the present, all the streams have employed 
 themselves in effecting an ever deepening erosion. Of the 
 greater arteries of the continental drainage, the ancient pre- 
 glacial bounding walls may sometimes still be traced. The 
 high cliffs of the Upper Mississippi show where the great river 
 
278 WALKS AND TALKS. 
 
 was bounded throughout all Csenozoic and Mesozoic time. 
 There was an epoch when the excavation of this gorge began. 
 The great tide swept along at the high level of the land. But 
 the stream has also scored deeper than at present. The rocky 
 bottom of its channel is everywhere many feet below the 
 present bed of sediment. The country stood higher once than 
 now ; the descent to the sea was sharper, and the erosion more 
 profound. 
 
 Of course, during the melting epoch, of the great glacier, 
 all the streams were flooded. Not only did the dissolving ice 
 supply enormous quantities of water; evaporation must have 
 been increased by the extension of evaporating surface, and 
 condensation must have been promoted -by the large amount of 
 ice-cold surface. It was an epoch of rains and floods. All the 
 rivers have left records of their ancient altitudes. These are 
 the terraces. On the Connecticut we find them from one 
 hundred and eighty to two hundred feet above present flood 
 level ; on the Hudson and Mohawk, three hundred and thirty 
 feet; on the Genesee, two hundred and thirty-five feet; on 
 the lower Ohio, fifty to one hundred and eighty feet ; on the 
 Missouri, two hundred and fifty feet ; and so throughout North 
 America, all the rivers at this epoch were flooded. 
 
 The Niagara river had been at work on a vast gorge ever 
 since the Devonian Age. Probably none of the great lakes 
 except Superior, then existed. From Lake Superior sprang 
 a river which flowed along a valley in which the basins of 
 Lake Huron and Lake Erie have since been excavated. At 
 a point west of the present mouth of the Niagara, it made a 
 fall, and flowed as a river along the Ontario valley, and thus 
 to the sea. In the course of ages, the stream excavated a 
 gorge as far as the whirlpool perhaps even farther. On the 
 re-establishment of the river, it did not find its ancient gorge, 
 but precipitated itself over the escarpment at Lewiston. 
 Here it began a new gorge, and dug back four miles, when 
 it struck the old gorge. Of course the falls now continued 
 their recession rapidly as far back as the head of the old 
 gorge. Since that was reached, the work has been contin- 
 
A GEOLOGIC SPRING TIME. 279 
 
 ued in solid rock, and is now proceeding at the rate of three 
 feet a year. 
 
 The question has been much discussed whether the basins 
 of the great lakes were excavated by the action of the conti- 
 nental glacier. By Ramsay, lake basins have been generally 
 attributed to such action. By others, the doctrine is held in 
 light esteem, since we have evidence, in some cases, that 
 glaciers have moved over sheets of clay without plowing them 
 up. I incline to agree in part with both. The positions of 
 the terminal and lateral moraines show that glaciers moved 
 along the beds of Lakes Erie, Huron-, and Michigan, and Sag- 
 inaw and Green Bays. What directed ice-streams to these 
 positions? A pre-existing valley. What caused the valley? 
 The erosion of the great river which had been flowing out of 
 Lake Superior during Mesozoic and Csenozoic ages. The val- 
 ley may have been a mile, or five miles, wide, and bounded 
 by precipitous rocky walls. When the glacier commenced its 
 movement along such a valley, it exerted powerful erosion 
 along the steep bounding walls, and wore them down to the 
 gentle slopes which now form part of the bed of the lake. 
 The basins of the lakes are demonstrably works of erosion. 
 Why the great glaciers worked there more than elsewhere, 
 was because the great river had inaugurated the work and in- 
 vited the glacier. A glacier also moved out of the western 
 end of Lake Superior. A valley already existed indeed a 
 lake basin existed, shaped by the ancient upheaval of rocks 
 along the northern and southern shores. 
 
 In regions where returning spring-time found the general 
 surface nearly level, and locally indented with basin-like 
 depressions, the Champlain floods formed large numbers of 
 lakes and lakelets. Such depressions might arise from the 
 rocky configuration of the country especially the larger de- 
 pressions. More generally they were mere intervals inclosed 
 by hills and ridges of Drift. Thus arose the numerous lakes 
 of Maine, Michigan, and Minnesota. Whenever a lakelet 
 found an outlet, the process of erosion began ; the lakelet was 
 continually lowered, and in many cases, it has been completely 
 
280 WALKS AND TALKS. 
 
 drained. In all cases, the filling of the lakelets has gone for- 
 ward in the manner described in Talk VIII. Nature is finish- 
 ing the world before our eyes. 
 
 It was during the spring-time empire of water, that the 
 Great Lakes stood at the high levels described in Talk VII. 
 To this inundation of Illinois, the prairies of the Mississippi 
 owe their origin. The prairie formation is a stratified deposit 
 of fine clay, sand, and alluvial matter. It is a fresh-water 
 deposit. It was laid down on the top of the Drift. The topo- 
 graphical and geological facts point to the great lacustrine 
 flood as the occasion. When, in the course of time, the high 
 waters subsided, the lake bottom was left exposed. It lay a 
 barren Avaste until the seeds of vegetation were distributed 
 over it by natural means. Birds and winds were the principal 
 agents ; but these agents transport only the lighter seeds the 
 seeds of grasses and herbs. The forest was standing thrifty 
 and green around the border of the ancient lake, but its 
 seeds found little opportunity to gain foothold on the old lake- 
 bottom. The Indian was here. He had paddled his canoe in 
 the waters above the soil which was now a prairie. When 
 the grasses and herbs had been browned by the first frosts of 
 Autumn, the Indian's torch set them ablaze. The air was 
 filled with smoke during the dry and sunny, days which fol- 
 low the killing frosts. The west wind wafted the smoke to 
 New England, and our ancestors said, "The Indian Summer 
 is here." But the burning killed the shoots of the young 
 trees without injuiring the roots of the grasses and sedges. 
 So when May covered the surface again with green, the 
 grasses were there, but the woody shoot was dead. Thus the 
 prairies remained treeless. When the emigrant discovered the 
 Indian at his annual burning, he said, " That is the explana- 
 tion of the treelessness." But he never explained why the 
 region was treeless enough in the beginning to allow the sur- 
 face to come into possession of the grasses, and furnish the 
 Indian occasion for the burning. 
 
THE EAETH KECEIVES HER KING. 281 
 
 EARTH: RECEIVERS HER KINO. 
 
 THE ADVENT OF MAN. 
 
 AT some juncture in the progress of these later events, 
 man made his first appearance on the earth. He was not 
 present during Tertiary periods, in any portion of the world 
 which has been subjected to research. There appears to have 
 been no European Tertiary man, and no American Tertiary 
 man. This conclusion is now almost universally accepted. 
 
 But both in America and Europe, man seems to have been 
 present during a portion of the Glacial Epoch. American 
 man dwelt in California. Along the Pacific coast, as I stated 
 in Talk XL VII, a milder climate prevented the prevalence 
 of universal glaciers. The situation, therefore; may have 
 been as favorable for human occupation as that in our day, 
 at the foot of the glaciated valleys of Switzerland. The 
 human remains of California, however, are found in situations 
 which at first excite our wonder; for they lie in the deep 
 placers underneath great tables of ancient lava (Talk XVI, 
 end). These lava-sheets, in the judgment of Professor J. D. 
 Whitney, were erupted in the latter part of the Pliocene 
 Epoch ; and if so, man was a Tertiary resident on the Pacific 
 coast. This opinion, I hav myself been disposed heretofore, 
 to adopt. (Preadamites, pp. 426-428). Every thing depends 
 on the epoch of the lava eruption. That would be given, if 
 the other fossil remains of the deep placers afforded unques- 
 tionable criteria of age. Professor Whitney thinks they do. 
 In his report on California he says: "The beds which were 
 deposited prior to the great volcanic disturbance and conse- 
 quent overflow of lava throughout the Sierra, inclose a pecu- 
 liar fauna which we refer to the Pliocene epoch, and which 
 appears to have some analogy with the group of the same 
 age occurring on the Niobrara and White Rivers and in their 
 vicinity, to the east of the Rocky Mountain chain." "Among 
 the animals of the Pliocene of California, or the group which 
 preceded the epoch of volcanic activity, we recognize the 
 
 24 
 
282 WALKS AND TALKS. 
 
 rhinoceros, an animal allied to the hippopotamus, an extinct 
 species of horse, and a species allied to the camel and resem- 
 bling the Meg-a-lo-me'-ryx of Leidy ; all these species, so far as 
 we know, are peculiar to the deposits under the lava." As to 
 the plant remains found in the same beds, Dr. Newberry re- 
 ports that they are not older than the Miocene, and most re- 
 semble species found in the later European Tertiaries. For 
 myself, I hardly think this evidence is fully conclusive on the 
 Pliocene age of the deep placer gravels with human relics. I 
 feel persuaded that the great lava eruption was connected 
 with the enormous load of ice which once covered the regions 
 farther north and east; and if so, they occurred probably 
 while the glacial epoch was at its meridian. Mr. Boyd Daw- 
 kins thinks the evidence of Pliocene man in California is "un- 
 satisfactory" because almost no species of Pliocene mammals 
 have survived to the present, and the strong presumption is 
 afforded that man is not an exception. 
 
 But in any event, American man existed in the Glacial 
 Epoch not, of course, in the midst of a continental glacier ; 
 but in some favorable region which glaciation did not reach. 
 Much of the " far west" was suitable for human occupation 
 at the time. Great lakes existed in Oregon, in Utah, and 
 Nevada ; and they were populated by a molluscan fauna not 
 less exacting in its requirements than the types accompanying 
 man in the present epoch. In eastern America, also, some 
 human relics have been found which, as is thought, argue the 
 presence of man in the Glacial Epoch. Dr. C. C. Abbot has 
 described some stone implements in ancient gravel near 
 Trenton, New Jersey, and the announcement of Glacial man 
 has been proclaimed ; but I agree with Mr. H. C. Lewis, 
 that these gravels are post-glacial. Stratified gravels of the 
 Drift belong to the epoch of the Champlain floods. The de- 
 posits of the Glacial Epoch, with local exceptions, are un- 
 stratified, and in the nature of "till." The Trenton gravel 
 appears to be a river-drift deposited during the flooded stage 
 of the Delaware. 
 
 Human implements in river-drift gravels are widely known 
 
THE EARTH EECEIVES HER KING. 283 
 
 in Europe. They occur especially along the valleys of the 
 Somme, the Seine, the Thames but also, in many other re- 
 gions. They have been the subject of voluminous discussion. 
 In Brazil, stone implements have recently been described in 
 large numbers from the gravels of the province Rio Gran-de 
 do Sul. From caverns many relics have been obtained, which 
 throw much light on the condition and associations of primi- 
 tive men. Numerous other facts have been yielded from the 
 bottoms of European lakes. It appears that the early inhab- 
 itants constructed their habitations on piles in the lakes, and 
 communication with the shore was effected by a bridge which 
 could be readily removed. Some of these piles still remain. 
 Naturally, many articles used by the dwellers in these abodes 
 were lost in the water and never recovered. Many thousands 
 have been dredged up in recent times. Another source of 
 light on primitive man is found in the sea-side accumulations 
 of kitchen-refuse piles of shells and bones and organic debris 
 reaching several yards in length, and sometimes eight or ten 
 feet high. These are the refuse of fishing villages. They 
 contain implements, domestic utensils, and personal ornaments 
 once belonging to the inhabitants. The peat bogs of Den- 
 mark and other countries give us other relics. From the 
 mounds and other burial places much further information is 
 obtained. 
 
 Among the relics of these early settlers in Europe, we find 
 many stone axes some rough and others laboriously polished. 
 Flint arrow-heads and lance-heads are very common. Fish- 
 hooks and other articles of bone occur in the lakes and the 
 shell-mounds. Very numerous articles of bronze used for 
 ornament are dredged from the lakes brooches, bracelets, 
 pins. Fragments of pottery occur in the lakes and shell- 
 mounds. Woven cloth has been exhumed from some of the 
 oldest deposits ; and jars of dried apples and wheat, and even 
 cakes, have been yielded from the pile-habitations. The older 
 relics are rudest, as might be expected; and consist exclu- 
 sively of stone and bone. Later, bronze came into use, and 
 the workmanship was finer. Lastly iron became known. 
 
284 WALKS AND TALKS. 
 
 Archaeologists accordingly divide prehistoric time into three 
 ages: 1. The AGE OF STONE; which was subdivided into the 
 Palceolitfiic or rough-stone epoch, and the Neolithic or polished- 
 stone epoch ; 2. The AGE OF BRONZE ; and 3, the AGE OF 
 IRON. Within certain geographical limits these three ages in 
 the progress of culture are consecutive. But it must not be 
 supposed that they mark periods in the history of man at 
 large. The Age of Stone is long past in Europe ; but it pre- 
 vailed still in the Hawaiian Islands when discovered by Cap- 
 tain Cook ; and still prevails among the Indians of America. 
 
 Gathering together the numerous facts which supply infor- 
 mation concerning the primeval inhabitants of Europe, we 
 are able to set the following inferences in order : When man 
 first made his advent in Europe, that continent was still the 
 abode of quadrupeds now long extinct. The caverns were 
 shared with man by the Cave Bear, the Cave Hysena, and 
 the Cave Lion. These gradually gave place to gigantic 
 Herbivores the Hairy Mammoth, the Hairy Rhinoceros, 
 and the Reindeer. The Mammoth roamed in herds over 
 the whole of Europe, Northern Asia, and North America 
 (Talk XXVII). The Hairy, or Two-horned Rhinoceros 
 in company with another two-horned species, thundered 
 through the forests or wallowed in the jungles and swamps. 
 The rivers and lakes of Southern Europe were tenanted by 
 the hippopotamus and the beaver. Three kinds of wild oxen, 
 two of which were of colossal strength, and one of these was 
 "maned and villous like the Bonassus," grazed with the mar- 
 mot and wild goat and chamois upon the hills and plains 
 which skirt the Mediterranean. The musk-ox and the rein- 
 deer browsed in the meadows of Perigord, in the south of 
 France, while a gigantic elk ranged from Ireland to the bor- 
 ders of Italy. 
 
 From similar evidences, we learn that primitive man in 
 America was also the contemporary of quadrupeds now long 
 extinct. Beneath the lava of California, the bones of the 
 mammoth and mastodon and the broad-faced ox lie mingled 
 with the bones and implements of man. East of the Rocky 
 
THE EARTH RECEIVES HER KING. 285 
 
 Mountains, the relics of the ancient proboscidians have often 
 been discovered in such association with human relics as to 
 afford strong evidence of contemporaneity. On the banks of 
 the Ashley River in South Carolina, human bones, arrow- 
 heads, hatchets and potsherds are found mingled with bones 
 of the hog, the horse, the mastodon, and extinct gigantic liz- 
 ards. In the same epoch lived the wide-faced bison, the 
 shrub-loving tapir and a gigantic beaver, and a number of 
 gigantic Edentates wanderers from South America. 
 
 If, from the monuments which these primitive people have 
 left behind, we attempt to form an estimate of their physical, 
 intellectual, and moral characteristics, we become at once 
 convinced that in their cranial characters they were equal in 
 rank to the average races of modern times. Beyond all ques- 
 tion, they were no connecting links between man and lower 
 animals. The evidences of their intelligence place them as 
 high as the Esquimaux. In mechanical skill they were 
 equal to the manufacture of a large assortment of imple- 
 ments of stone and bone. Before the close of the Stone Age, 
 they produced many evidences of an aesthetic faculty. They 
 polished their stone axes, and worked their arrow and lance 
 heads after more elaborate and artistic patterns. Their pot- 
 tery began to receive some crude decorations. They carved 
 the bone and horn handles of some of their weapons. They 
 engraved on slate, ivory, and bone the figures of familiar ani- 
 mals; and among these portraits are sketches of the hairy 
 elephant, furnishing further evidence of their contemporane- 
 ous possession of the forest and the plain. These men also, 
 possessed a religious nature. There are certain emblems and 
 objects which, by general admission, must receive a religious 
 interpretation. The care bestowed on the dead evinces a be- 
 lief that even after death they retained relations of love and 
 recognition. They sent them on their mysterious journey 
 with such offerings and supplies as should meet their neces- 
 sities. The idea of future life dwelt in their breasts ; even 
 these poor fore-runners of our humanity dreamed of a happy 
 world beyond the pains and trials of mortal dissolution. 
 
286 WALKS AND TALKS. 
 
 They felt the notion of a Supreme Divinity stirring within 
 them. A little later they erected altars and built rude tem- 
 ples. The paraphernalia and accessories of worship imply a 
 Being worthy of worship. The Stone Folk of Europe were 
 every way MEN. 
 
 Who were they? And whence did they come? The 
 latest researches show their skulls to possess affinities with the 
 Mongoloid race. They were not members of the White race. 
 Modern Europeans are not descended from them ; but un- 
 doubtedly their blood mingles with that of Europeans, and 
 some ethnologists think the different types of prehistoric peo- 
 ple can be detected in the populations of different parts of 
 Europe. On the whole, there are many reasons for believing 
 the stone folk nearly related to modern Esquimaux and 
 Laplanders. 
 
 But when we shall have reached every possible conclusion 
 from the study of prehistoric Europeans, we lack much of 
 penetrating the mystery of the human species at large. These 
 men were not the first men who ever lived. They came from 
 somewhere. If they were Mongoloids, they came, in all prob- 
 ability, from Asia. Whoever they were, they had spread 
 over all Europe, Asia, and North Africa before the first white 
 men visited those regions apparently as early as 4000 B. C. 
 The Pelasgic empire was at its meridian about 2500 B. C. ; 
 and the Pelasgians were the first descendants of Noah who 
 penetrated beyond the borders of Asia. These primitive Mon- 
 goloids, known to antiquity as Cyclopes, had dispersed them- 
 selves over America probably at a date equally remote. 
 
 Beyond these general determinations we have neither his- 
 tory, tradition, or monuments to light our path. The succes- 
 sive migrations of families of the White Kace from Asia into 
 Europe are fairly well cleared up. We follow first the Ha- 
 mites (Pelasgian Egyptians), then the Semites (Phoenicians, 
 Tyrians, Carthaginians) and lastly the Japhetites (Thracians, 
 Hellenes, Ligures, Ombro-Latins, Kelts). But what were 
 the genetic relations between these Asiatic peoples and the 
 Asiatic Mongoloids? Whence came the White and Mongo- 
 
THE EARTH EECEIVES HER KING. 287 
 
 loid races into Asia ? What relations do they or either of 
 them sustain to the Australians leathery skinned and curly- 
 haired ; to the Papuans black and tuft-haired ; to the Hot- 
 tentots coffee-colored and kinky-haired ; to the Negroes 
 ebony-black and woolly-haired ? What is the relative rank 
 of these several races? When did they severally begin to 
 exist ? Where did the first men appear ? Who was Adam ? 
 Are all these peoples descended from Adam ? These are in- 
 teresting questions which strike us at this point, and are 
 worthy of study ; but I do not regard it expedient to enter 
 upon them at the present time. The reader who may desire 
 to see what can be said about them, may consult "Preadam- 
 ites; or, a Demonstration of the Existence of Men before 
 Adam" a work which is essentially a commentary on portions 
 of Genesis and a vindication of Biblical ethnography. 
 
III. 
 RETROSPECT; 
 
 OR, 
 
 HOW THE STORY OF THE WORLD IMPRESSES US. 
 
 Iv. THE ABYSS OK* CENTURIES. 
 
 THE AGE OP THE WORLD. 
 
 WE stand finally at the end of the world's long history. 
 From fire-mist to man we have flitted in thought, and have 
 taken some note of the grand events of each aeon. We pause 
 now, to indulge in reflections. How inexpressibly magnifi- 
 cent a career ! How inconceivably vast the stretches of space 
 and time which it spans! How many centuries must have 
 been swallowed up in the stately transformations of the origi- 
 nal nebula ! There are other nebulae in our modern universe, 
 and we gaze on them from year to year, and fail to note the 
 progress of any change. But they are changing before our 
 eyes ; and we are beginning to record some slight variations 
 from their first observed aspects. How long a time is re- 
 quired for one revolution of a mass of nebular vapor a hun- 
 dred billions of miles in diameter, who can calculate? Who 
 guess ? How long to reach the ring-making rate of rotation 
 how long to throw off a system of planets and condense 
 to a sun ? 
 
 Yet there are some data for a calculation. I might even 
 lead you to understand what are the grounds of a mathemat- 
 ical estimate, but it would too much lengthen this Talk. Pro- 
 fessor Newcomb has calculated that the heat evolved by the 
 contraction of the matter of the sun from an infinite distance 
 would last only eighteen million years. He assumes the sun's 
 288 
 
THE ABYSS OF CENTURIES. 289 
 
 matter to have been infinitely dispersed, and assumes that all 
 the heat ever existing in the contracting mass arose from the 
 process of contraction. Of course, if the sun's matter in 
 other words, the matter of our primitive nebula did not ex- 
 tend an infinite distance, the time for contraction would be 
 shortened. He says a temperature permitting the existence 
 of water on the earth would have been reached ten million 
 years ago. 
 
 Professor Newcomb calculates further, that the sun in its 
 process of cooling will reach a darkened or planetary state in 
 twelve million years. So the whole life-time of the sun from 
 infinitely expanded fire-mist to final darkness, spans only 
 thirty million years. 
 
 Sir William Thomson has calculated the time required for 
 the earth to cool from incipient incrustation to its present 
 state. He thinks it would not exceed eighty million years. 
 Kev. O. Fisher, in making the same calculation deduces thirty- 
 three million years. These estimates do not cover precisely 
 the same stage of cooling as either of Newcomb's, but the 
 numbers appear to be relatively higher. 
 
 Another way of getting at the length of any particular 
 period of the world for instance, the time elapsed since the close 
 of the Tertiary is first to compute the relative duration of 
 the different ages on the basis of thickness of formations, and 
 then divide some assumed total age in the same proportion as 
 the relative ages. To make this plainer: A formation two 
 hundred feet thick has probably consumed more time than a 
 formation one hundred feet thick. We do not know whether 
 the rate of accumulation was the same for the two formations, 
 but we must assume it the same, if the materials are the same ; 
 if however, one is of limestone and the other of fragmental 
 materials (sand, pebbles, clay) we may assume the rate of 
 accumulation five times as great for the latter as for the lime- 
 stone. Thus the formation one hundred feet thick, of lime- 
 stone would be equivalent in time to 500 feet of sandstone. 
 Now, we have carefully studied the thickness of all the for- 
 mations, making due allowance for all the limestones. We 
 
 25 
 
290 WALKS AND TALKS. 
 
 have an aggregate thickness, and the thickness of each Group, 
 System and Great System of strata. If we assume the whole 
 time represented in these formations to be eighty million years, 
 then the duration of the Eozoic jEon was eleven million 
 years ; the duration of the Coal Peroid, two and a half mill- 
 ions, the duration of the Mesozoic, eight millions ; of the 
 Caenezoic two and a half millions, and the time since the close 
 of the Tertiary, half a million; the Glacial period endured 
 352,000 years and the post-glacial interval has been 176,000 
 years. If we make Newcomb's calculations the basis of an 
 estimate, all the above intervals will be reduced to one-sixth. 
 The post-glacial period will be 30,000 years. These are, to a 
 large extent, random results; but they show, at least, that 
 the history of the world is embraced within a finite space 
 of time. 
 
 Another method of gaining some conception of the length 
 of geological periods is based chiefly on changes in the eccen- 
 tricity of the earth's orbit. The earth's path about the sun, 
 as you remember, is an ellipse. But this ellipse is constantly 
 varying its elongation. For many centuries it increases its 
 elongation, and then for many centuries diminishes it. It was 
 shown by James Croll that when the eccentricity (elongation) 
 is greatest, the climates of the earth must be affected in such 
 a way as to lower the mean temperature of the northern 
 hemisphere. He contends that the advent of the Glacial age 
 was due to a state of maximum eccentricity. But the changes 
 in eccentricity are subject to a law by which the epochs of 
 maximum eccentricity have been calculated. The last max- 
 imum occurred 100,000 years ago, and the next preceding, 
 210,000 years ago. Mr. Croll thinks, therefore, that the 
 Glacial period began about 240,000 years ago, and continued 
 to 80,000 years ago, with a mild interglacial epoch 150,000 
 years ago. Now, if Mr. Croll is right in ascribing glacial 
 periods primarily to maximum eccentricity, it would appear 
 that the decline of continental glaciation took place about 
 80,000 years since. This high number is not confirmed by 
 any of the other methods of computation. There is nothing 
 
THE ABYSS OF CENTURIES. 291 
 
 to sustain so high a figure except the general guesses of cer- 
 tain people who "entertain no doubt that man has been on 
 the earth one or two hundred thousand years." 
 
 The problem may be attacked in quite a different way. 
 We have noted vast erosions which have taken place during 
 the history of the world. If we could only obtain a clew to 
 the rate of any one of these erosions, we could soon calculate 
 how much time was required for the work. Now, the Niagara 
 gorge presents a specific and measurable amount of work ; and, 
 if we can determine how much of that work is accomplished 
 yearly, we shall have the age of the gorge. This problem is 
 so intelligible that it has received the attention of many in- 
 vestigators. But their results have been widely divergent. 
 The whole gorge is seven miles long. Mr. Robert Bake well 
 made its age 12,300 years. Messrs. Lyell and Hall made it 
 35,000 years. Mr. E. Desor, who assumed much too low a 
 rate of erosion, assigned 1,232,000 years. Mr. Jules Marcou 
 found data to make it 64,842 years. These wide discrepancies 
 arise from the difficulty of ascertaining the rate of recession. 
 Within a few years that has been well settled at about three 
 feet a year. Professor James Hall, in 1842, caused to be made 
 a trigonometrical survey of the falls, and fixed permanent land- 
 marks. In 1875, Mr. James Gardner, Director of the New 
 York State Trigonometrical Survey, repeated the survey of the 
 Falls, and ascertained that there had been a recession of at 
 least one hundred feet in thirty-three years. This rate would 
 give 12,300 years as the age of the whole gorge, from Lewis- 
 ton. The three miles below the "whirlpool," where the new 
 gorge intercepted the old one, would have required 5,280 
 years. As we may fairly assume that the old gorge extended 
 some distance above the whirlpool, we may conclude that the 
 work of the modern river has extended over a period between 
 5,280 and 12,300 years. From what I have stated in Talk 
 XL VIII, you will understand that the work of the modern 
 river is post-glacial work, and these numbers concern the 
 duration of the post-glacial period. 
 
 I have said that the old gorge from St. David's was the 
 
292 WALKS AND TALKS. 
 
 work of Mesozoic and Caenozoic time ; but the whole length 
 of that gorge, even up to the present site of the Falls only 
 about six miles is far too little work for such a river as the 
 Niagara to have performed in the million or more years which 
 we allow for that time. I will, therefore, now make the 
 statement that only a part of the water which came into the 
 basin of Lake Erie (a mere river then) found its outlet by St. 
 David's. There seems to have been, at one time, an outlet 
 through the Cuyahoga Eiver, whose bed at Cleveland is two 
 hundred feet below its present bed, and perhaps for many 
 ages, the whole stream was carried off in that direction to the 
 Ohio. There seems to have been also, at some time, an out- 
 let to the basin of Lake Ontario, from the mouth of Grand 
 River of Canada. Possibly the drainage passed through one 
 or the other of these channels during most of Mesozoic and 
 Csenozoic time. 
 
 The recession of the Falls of St. Anthony has been studied 
 by Professor N. H. Winchell. This, he maintains, is also a 
 post-glacial erosion as far as Fort Snelling. From the study 
 of old documents he ascertains that the rate of recession from 
 1680 to 1856 was about 5.15 feet a year. As the whole dis- 
 tance is eight miles, the time required is 8,202 years. 
 
 A thorough scientific survey of the Mississippi, by author- 
 ity of the general government, was concluded some years ago 
 by Messrs. Humphreys and Abbot. They calculated that 
 5,000 years had been required for the accumulation of the 
 Mississippi Delta. This assumes, of course, uniformity in the 
 rate of deposition, while it was probably more rapid during 
 the rainy Champlain period ; but, on the other hand, the in- 
 terval expressed reaches from the close of the glacial reign, 
 not from its "acme" as in the calculation on the Falls of St. 
 Anthony. 
 
 Similarly the age of the Nile delta has been set down at 
 6,350 years. 
 
 A very ingenious calculation of the length of post-glacial 
 time has been based by Dr. E. Andrews on the rate of bluff- 
 erosion and terrace formation near Chicago. North of Chicago 
 
THE ABYSS OF CENTURIES. 293 
 
 the lake is wearing away a bluff at a rate which has been 
 ascertained. The submerged stump of the bluff permits a 
 measurement of the whole cubic contents removed. From 
 this and the rate of erosion, the time required appears to be 
 2,720 years. The material of the bluff was deposited in a ter- 
 race at the south end of the lake, and this, therefore, has the 
 same age as the erosive process. Next, he finds above the 
 bluff, at a higher level, two sand beaches which must have 
 been deposited when the lakes were at flood. How long a 
 time was required for their deposition? By comparing their 
 volume with that of the sand beach at the south end of the 
 lake, whose age is known as 2,720 years, he finds the high 
 beaches required about 2,570 years. Therefore, from the be- 
 ginning of high water to the present, the interval is expressed 
 by the sum of the age of the upper beaches and the age of 
 the erosion, that is 5,290 years. Dr. Andrews thinks the real 
 interval is somewhere between 5,300 and 7,500 years. 
 
 As the upper beaches must have worn away to some ex- 
 tent during their prolonged exposure ; their age is somewhat 
 greater than Dr. Andrews has estimated. Making allowance 
 for this, the result is not far from that based on the recession 
 of the Falls of St. Anthony. 
 
 We have then several results based on rates of erosion, 
 which stand satisfactorily accordant. For myself, these meth- 
 ods appear more reliable than those depending on mathemat- 
 ical calculations. The results of mathematics are so precise 
 and demonstrative when the data are adequate, that we are 
 tempted to trust them. But very slight errors in the con- 
 stants assumed often lead to enormous errors in the result; 
 and it must be admitted that we discover too many chances 
 of error in the data involved in mathematical calculations 
 respecting the age of the world, to feel that the results are 
 trustworthy, or equally trustworthy with the results based 
 on observed data which bear a larger ratio to the unknown 
 quantity. 
 
294 WALKS AND TALKS. 
 
 1,1. THE METHOD OK CREATION. 
 
 THE QUESTION OF EVOLUTION. 
 
 LET us suppose Matter, Energy, and Law in existence. 
 This stupendous system of things which we have been contem- 
 plating implies the reality of some substance which is the un- 
 derlying ground of its being. It is a system of things, not of 
 'names. It implies the exercise of power, or force ; for out of 
 matter, something has been formed, and the forms of matter 
 have been changed. It implies the existence of method ; for 
 forms exist in certain fixed relations to each other, and 
 changes occur in some regular order of succession ; and an 
 ordained and established correlation of forms or order of suc- 
 cession is a law. Matter, energy, and method (law) came 
 into existence somehow ; let us grant that but we need not 
 here inquire how they came to exist. It is only the nature of 
 the method or law, in accordance with- which energy shapes 
 matter and determines successions of forms and events, that 
 we are to consider. What is Nature's fundamental method? 
 
 Allow me first to enunciate the method. I will then pro- 
 ceed to cite facts which will both illustrate and establish the 
 proposition. Nature's fundamental method is a procedure, through 
 continuity, from the general to the particular. Do not be alarmed 
 at the form of the phrase which conciseness and accuracy of 
 statement necessitate. The idea is very simple, and you will 
 soon perceive it so. By "continuity,"! mean that Nature 
 retains the same matter in bringing into existence many modi- 
 fications in succession ; she does not drop and abandon the 
 matter of one conformation when she proceeds to another; 
 but she retains the same matter, and modifies it into the new 
 conformation. The frog, for instance, is the tadpole modified. 
 An apple is a full-grown element which existed in the flower, 
 and in the bud. By proceeding "from the general to the 
 particular," I mean that each modification of matter, in a 
 series of modifications, contains some added features, together 
 with a clearer exhibition of the older features. As when a 
 house is to be built, the rough frame is first constructed 
 
THE METHOD OF CREATION. 295 
 
 the corner-posts, the upright timbers, the joists, the rafters, 
 the partition studs. Then come the flooring, the lathing, the 
 siding, and the roof boards. Next, the plastering, the base- 
 boards, the casings, the doors, the windows. Finally, the 
 painting, the graining, and the decorations. Here the pro- 
 cedure is by continuity, and from general to particular. That 
 is, the material employed in first rough outline remains, and 
 the modifications consist in the addition of successive details- 
 and particulars. Now this is Nature's method as well as 
 man's. I think I can show you that such is the case. 
 
 Consider first, the realm of inorganic matter. I think we 
 are entitled to trace the train of events back to a disseminated 
 cosmical dust, which reveals its existence in meteors, comets, 
 and nebulae. Reflect then, that the same matter which floated 
 cold in space, appeared later as a fire-mist, then -a planetary 
 ring, then a darkened planet, a solid continent, a tree, or a 
 human body. It is a wonderful thought ; but I believe we 
 must admit its truth. Here is continuity. Then notice the 
 other conception in Nature, jnethod, specialization. The first 
 condition of matter was chaotic ; no form was outlined in it. 
 Little less chaotic was the nebulous or fire-mist stage. The 
 idea of limits and form began to be expressed. When a ring 
 was abandoned; when two spheres existed, some advance in 
 detail was achieved. Still more when other rings, other 
 spheres primary and secondary, came in due order, as modi- 
 fications out of the original matter. The progress of each 
 separate planetary sphere carried forward the method of 
 specialization. The earth, for example, was fire-mist; then a 
 molten globe with a mixed atmosphere; then an incrusting 
 globe ; then an incrusted globe with an ocean film about it; then 
 all this with emergent nuclei of continents; then further 
 emergences, with added layers of rocks ; and then an atmos- 
 pheric specialization by the separation of carbon and a new 
 kind of rock ; then further emergences and more complicated 
 rock arrangements; then a detailed sculpturing and rough 
 wastage of the land ; then the glacial repair of the land ; 
 then a continuance of erosive and modifying actions, to the 
 
296 WALKS AND TALKS. 
 
 present time. The continent grew by continuity, and im- 
 proved by ever increasing specialization. The great delta 
 started at a point and grew by additions to itself, and by 
 ever widening relations to the land, and ever increasing com- 
 plications of structure. So every feature of the earth grew. 
 The whole history of the physical world exemplifies a method 
 of specialization tftrough continuity. 
 
 Consider next, the realm of organic matter. Under what 
 method does Nature produce an animal or a plant? By 
 what method has the world been populated? What method 
 has been pursued in the geological succession of organic forms 
 which we have passed in review ? 
 
 To learn by what method Nature produces an animal, we 
 must trace its history from the earliest condition in which it 
 exists. Every animal exists first as an egg that is, a certain 
 amount of yolk with an included cell in which is a point 
 where the force is seated which we will call "vital," and 
 which, though inscrutrable, is the essential part of the egg. 
 In viviparous animals, the eggs are developed within the 
 parent. In any order of animals, when the conditions are 
 suitable, the yolk, whether of an external or an internal egg, 
 begins to undergo changes. The yolk, or a portion of it, 
 divides into two parts ; then each of these, into two ; and this 
 subdivision proceeds until the whole yolk, or the divided por- 
 tion of it, is a mass of globules aggregated together, and pre- 
 senting the appearance of a mulberry. On and within this 
 mass, a disc (blastoderm) appears, consisting of two layers, 
 the upper (epiblast) formed of nucleated cells, and the lower 
 (mesoblast) of irregularly rounded cells. From the upper are 
 destined to be developed the skin and walls of the body, 
 together with the nervous chord ; from the lower, the heart 
 and vascular system, the stomach and intestines. I will only 
 mention a few features in the development. The lower layer 
 undergoes progressive changes. We perceive the faintest 
 rudiments of head and tail, and abdominal cavity. The out- 
 lines of the neural canal appear, and of some of the first ver- 
 tebrae. Now the lower layer splits, and one part proceeds to 
 
THE METHOD OF CREATION. 297 
 
 form the body walls and the other the digestive organs. Some 
 curious accessory parts appear. Next, the divisions of the 
 brain-regions appear, and the vertebrae increase in number. 
 The heart begins to beat as a flask-shaped organ ; two aortse 
 result from its division ; and other blood-vessels arise, but 
 only of a temporary character. Blood cells appear ; the sec- 
 ond and third divisions of the brain are differentiated ; also, 
 the beginnings of eyes and ears. Bronchial fissures appear in 
 the sides of the neck. Thus the development proceeds. I 
 wish to mention only details enough to show that the embry- 
 onic history of an animal is a fine exemplification of Nature's 
 method material continuity, and progress from the more 
 general to the more detailed. The history of the individual 
 is often called Ontog'eny. 
 
 But what now, of the assemblage of animals living on the 
 earth? There are many different species; there are very 
 divergent classes; has not each separate species, or at least, 
 class, had a separate beginning ? Let us consider. There are 
 no two animals precisely alike. There is diversity in a single 
 litter of kittens. There are no two men or women precisely 
 alike. Even the same man differs from himself as a boy or a 
 babe, and differs to a very great extent. But two persons, 
 though differing, may be brothers; and though differing they 
 may have very pronounced family resemblances. Two men 
 who are cousins may show less distinct resemblance because 
 their relationship is more remote, as we would explain it ; but 
 still there is a real resemblance ; and we feel safe in declaring 
 it to arise from a real blood-relationship. So all the members 
 of the Napoleon family, or the Potter family, may show some 
 common cast of features which reveals their blood affinity. 
 We feel sure of this. 
 
 Similar family resemblances may be traced among lower 
 animals. Take the domestic cats ; how wide their divergences, 
 yet how close their resemblances. These animals we know 
 possess a common lineage, and by that we explain their resem- 
 blances, in spite of their divergences. But in -the cat-family 
 at large, are several other forms which differ from the domestic 
 
298 WALKS AND TALKS. 
 
 cats only in the same way as the latter differ among them- 
 selves. The ground for asserting that the panther, the leopard, 
 the tiger, the ocelot are descended from some common ancestry is 
 precisely the same as for maintaining, among domestic cats the 
 common ancestry of the brindled Tabby, the tortoise-shell 
 Spanish, the slaty Chartreuse, the short-tailed Malayan, and 
 the tailless Manx. The analogies compel us to admit that all 
 the members of the cat-family are related by blood. We must 
 say the same of the dog-family, and of the other families 
 which include the horse, the ox, the sheep, the squirrel, and 
 also, the families of the lower classes, Birds, Keptiles, and 
 Fishes. 
 
 But it is impossible to stop here. The Lynx family and 
 the Cat family do not differ more than Africans and Europeans ; 
 there is the same reason for recognizing in them a common 
 descent. So of the dog-family and the hyaena-family. So of 
 the perch and sun-fish families. So of all families. And now 
 to make the matter short, for lack of space, I venture to state 
 in general, that in the structural affinities of all animals 
 certainly those of the same sub-kingdom we have relation- 
 ships which justify the inference of common genealogical de- 
 scent. The differences have arisen partly from differences in 
 situation and a tendency in the organism to vary in the direc- 
 tion of better adaptation to the environment. 
 
 What next, of the succession of animals in geologic time ? 
 I think you are ready to admit that the succession is a real 
 progress. I think you will admit in several instances, the 
 graduation from lower to higher is shown to proceed by very 
 short steps. Consider especially, the horse-series, and the two 
 series reaching from reptiles to birds (stru'thious and carinate) 
 (Talk XLV). Remember that these are only instances out 
 of many which are similar in meaning, though less striking 
 in completeness. Consider the probability that if the record 
 of extinct life were fully restored, we should recognize the 
 entire succession as a nicely graduated series, with numerous 
 diverging branches also nicely graduated the whole reaching 
 from some primeval type through many ramifications, to the 
 
THE METHOD OF CREATION. 299 
 
 diversified forms of the present epoch. That is the conclusion 
 toward which we are tending; and it is wiser to anticipate 
 and welcome it than to turn our backs on it when we see it 
 looming in sight. 
 
 Suppose then that animals have succeeded each other in 
 nicely graduated series ; that does not demonstrate any genea- 
 logical connection between them ; it only permits us to accept 
 a theory of such connection. Each separate form in the suc- 
 cession may have been a separate origination. I ask you then 
 to turn to another set of facts very remarkable and very 
 suggestive. I refer to comparative embryology. A careful study 
 of many developing embryos, amongst animals of all ranks, 
 leads to the following conclusions: 1. Every embryo passes 
 through the same identical series of stages, up to the point 
 where it becomes adult. The higher embryos, therefore, pass 
 through a longer series, the lower, a shorter series. 2. The 
 embryonic gradations are the same as the gradations of the 
 animal kingdom -presented in a classification. One of the 
 primitive states of the embryo corresponds to the lowest 
 known type of animal; the next state, to the type next 
 superior; and so on. The human embryo, in the progress of 
 development, resembles an Amoeba, a Brachiopod, a Worm, a 
 Lancelet, a Shark, a Quadruped. Ihese are not fancies, but 
 solid facts ; and it is our business to find out what they mean. 
 3. The succession of extinct animals presents a gradation 
 which is closely analogous to that presented in the gradations 
 of living animals, and again in the embryonic stages of every 
 individual. We have thus the same succession of ideas three 
 times repeated. Does that show any connection between the 
 successions, so that one may have been derived from and 
 caused by another? Or shall we say this is all coincidence? 
 Believing in intelligible relationship of things, I choose to 
 call this a case of that kind. That is, the gradation of living 
 animals and the gradation of extinct forms result from the 
 gradation of the embryonic series in the individual. It must 
 be that ; for the individual is the starting point of all organic 
 phenomena. But, in the embryonic series, we know that each 
 
300 WALKS AND TALKS. 
 
 phase is derived from the preceding phase through a material 
 continuity. The developed embryo is all made of the very 
 yolk-stuff which existed in the beginning. If the living 
 gradation is derived from the embryonic, there must be a 
 material continuity or relationship among living animals as 
 we already inferred from their resemblances. If the palseon- 
 tological gradation is derived from or determined by, the 
 embryonic, so there must have been a material continuity 
 running through the palseontological series, as we could 
 easily infer from their successional resemblances. Each new 
 species is derived from a predecessor. The highest and the 
 living forms are only the last terms of a long series of 
 generations. 
 
 Do not be alarmed at the conclusion. If it is true, it is 
 precisely what we are interested in finding out. If it is not 
 true, then science herself will disprove it. Our fears of con- 
 sequences, our unscientific objections and prejudices count for 
 nothing, except as complaints against God's method in the 
 world. 
 
 L/II. THE HUMAN K ACTOR IN THE 
 VICISSITUDES. 
 
 MAN IN THE LIGHT OF SCIENCE. 
 
 Now that we have traveled over the entire course of ter- 
 restrial history, we seem to have attained an eminence from 
 which we can take some comprehensive glimpses of the whole 
 in its relations. Now that we find man to stand at the end 
 of that history, we are able to comprehend the relation which 
 he sustains to its successive steps. Let us look over the field 
 and see what it suggests. 
 
 We learn, first of all, that man is the fulfillment of the 
 prophecies of the ages. The first step of organic progress led 
 toward man. It determined the direction of the course of 
 organization, and now that we know man was destined to 
 stand at the end of that progress, we understand that the 
 law of progress contemplated man. Striking illustrations of 
 
THE HUMAN FACTOR. 301 
 
 progress are distinctly traceable in the history of Vertebrates. 
 The first vertebrate was a prophecy of man. In the skeletal 
 structure of the humble Devonian fish, man existed in poten- 
 tiality. The whole general plan was destined to endure 
 through the history of life, and unfold in man. The Amphib- 
 ian, the Reptile, the Bird, and the Quadruped are only suc- 
 cessive modifications of the vertebrate conception embodied in 
 On'chus and Onych'odus. Still more striking are the successive 
 modifications of vertebrate limbs. In the pectoral fin of the 
 fish, we have a number of bony, articulated rays, which an- 
 swer to digits; and above, are carpal and metacarpal bones, 
 and finally, radius and ulna, humerus and scapula, exactly as 
 in all other vertebrates. When, with the commencement of 
 the purification of the air, the situation was suited to low air- 
 breathers, the pectoral fin was modified into a five-toed fore- 
 foot. When, later, the situation demanded a more perfect 
 air-breather, the reptilian limb appeared. If the reptile was 
 appointed to swim in the sea, its hand was shaped into a pad- 
 dle, sometimes with six digits and many phalanges, as in the 
 fish. If it was destined to fly, a finger was enormously elon- 
 gated, and a skinny membrane was stretched from finger to 
 hind-limb and tail. When the time came for the fitting of a 
 vertebrate to make its home in the air, the bones were made 
 hollow, to combine lightness and strength. The hand and 
 fingers were abbreviated and consolidated ; cartilage was at- 
 tached along side, and in this were inserted the broad light 
 quills which form the expansion of the wing. But here we 
 find all the structures contained in the reptilian foot, except 
 so far as changed function demanded modification. When 
 locomotive appendages for an animal of mammalian rank were 
 needed, the same set of bones was further modified to meet 
 the exigencies of different situations, instincts, and habits. 
 The paddle of the whale, the shovel of the mole, the clawed 
 foot of the cat, the cloven hoof of the ox, the solid hoof of 
 the horse, the wing-frame of the bat all are but modifications 
 of the same bony elements, adjusted in the same way, but 
 modified in relative development. All this was prophetic of 
 
302 WALKS AND TALKS. 
 
 man. When an animal was to appear whose forward ex- 
 tremity should rise above the simple function of locomotion 
 and seizing of prey an animal that should swing an imple- 
 ment of civilization, ply an oar, wield a pen, manipulate a 
 needle, make a watch, play a violin, emphasize thought by a 
 gesture, execute the behests of intelligence rather than of 
 appetite and passion then assuredly, a different and nobler 
 plan of structure must be devised. No, it is the same old 
 plan. All these resources existed potentially in the clumsy fin 
 of the fish. Thus is man related to the plans of the present ; 
 thus, to a plan which has persisted for millions of years ; and 
 thus, was man all the time anticipated and approached, 
 during the progress of the transformations wrought by 
 the ages. 
 
 I will simply recall here what has been said about the an- 
 ticipation of man in the provision of beds of coal laid by 
 from the poison which once infected the atmosphere, and 
 barred the march of progress. No other corporeal being has 
 been capable of comprehending the uses of the coal ; no in- 
 corporeal being had need of coal. It is something which 
 stands in relation only to man ; for man it was designed. We 
 may say the same of iron, silver, and the other useful products 
 of the mineral kingdom. It is only to man that they are 
 useful. Man is the fulfillment of the prophecies of the ages. 
 
 We understand now, that man's birthplace was foreshad- 
 owed. It was expressed in the formal gradation of the conti- 
 nents. They are graded, in the present epoch. The mam- 
 malian fauna of Australia is almost exclusively Marsupial ; 
 that of South America is characterized by abundance of 
 Edentates ; that of North America is predominantly Herbiv- 
 orous, while Carnivores take the lead on the eastern conti- 
 nent. A similar gradation existed in the age before man. 
 The mammalian fossils of the Tertiary are, in Australia, pre- 
 dominantly marsupial ; in South America, edentate ; in North 
 America, herbivorous ; in the Orient, carnivorous. The apex 
 of organization in the age before man, was located in the 
 Orient. It might have been anticipated, therefore, that when 
 
THE HUMAN FACTOR. 303 
 
 the apex should rise to the grade of man, the Orient would be 
 the theater of its display. 
 
 Man seems signalized as the last term in the series of or- 
 ganic improvements. His erect attitude gives us an intima- 
 tion. The first vertebrate swung horizontally in his native 
 element. The Amphibian could slightly elevate his head. 
 The Reptilian head could be raised to a higher angle; and the 
 highest reptiles could rise on four feet, or even ambulate as 
 bipeds though withal, in an awkward way ; but all reptiles 
 dragged a cumbrous tail prone on the ground. The Bird 
 perched in an oblique attitude, and raised the head for an 
 outlook ; but when he swam through the air, he took the at- 
 titude of a swimming fish. The Ape could clumsily stand on 
 two feet, and wield a weapon with his hands ; but the very 
 shape of the foot, and the unmuscular leg show that Nature 
 never designed him for a habitual biped. Man alone, finds 
 the upright attitude quite natural and comfortable. Here has 
 been a progressive upward inclination of the spinal axis. 
 Vertical in man, the progress comes to a limit. This crite- 
 rion is not suited to index any further improvement. We 
 infer that no further improvement will present itself to 
 be indexed. 
 
 The same inference is sustained by man's cosmopolite adap- 
 tations. From the beginning of life on the earth, the range 
 of individual species has been narrowing. The Brachiopods 
 and Trilobites of the Cambrian ranged through wider seas 
 than those of the Carboniferous. Land animals, when they 
 appeared, were fenced within still stricter limits; and when 
 the mammals came upon the theater of being, each species 
 almost each genus was assigned to a particular corner of one 
 continent. Under this law of progressive restriction of faunal 
 range, man should have been shut in a narrower field than 
 any of his predecessors. He is not. On the contrary, all re- 
 strictions are removed. Man ranges over every continent and 
 through every clime. No conditions are too hard; no diffi- 
 culties insurmountable. Nature seems to have reached a 
 point where a new policy is inaugurated. The shackles are 
 
304 WALKS AND TALKS. 
 
 removed. Man is free to possess the earth. With man in 
 possession of the earth there is room for no wider ranging 
 animal; there is place for no successor. 
 
 Nature in man seems to have reached a period. While 
 other animals rise in steady gradation from lower to higher, 
 man proceeds by one grand leap to possess a rank and dignity 
 unapproached by his best predecessors. In intelligence, in 
 aesthetic perceptions, in moral sense, in religious susceptibility, 
 in theistic apperceptions, he stands separated by an unbridged 
 gulf from his mammalian fellows. Man is the capital and 
 completion of the long-rising column of organic life. The 
 structure is finished. 
 
 Man's advent is geologically recent. No report of a human 
 relic has been made by any geologist, from any formation be- 
 low the Miocene. No report of Miocene or Pliocene man has 
 been corroborated by such evidence as to claim the sanction 
 of conservative geologists. European man is first a Quater- 
 nary phenomenon ; he dates from the epoch of flooded streams 
 and glacier decline. I had once thought Pliocene man existed 
 in America ; but for reasons explained in Talk XLIX, I am 
 led to suspect the lava outflow which provided his sepulcher 
 was an event of the Glacier epoch. It will be noticed that 
 European discussion always concerns the man who first in- 
 vaded Europe. We have no facts bearing on the date of 
 man's advent into Africa and Australia. He may have existed 
 there during the reign of ice in the north; he may have pre- 
 ceded the reign of ice. If Mongoloid man was in Europe 
 immediately on the decline of the glaciers, the lower races 
 should have lived somewhere in an earlier epoch. But this is 
 only a suggestion. 
 
 Geological man, as far as known, was the equal of existing 
 races. The European Troglodytes were Mongoloids of the 
 grade of Esquimaux. There is no structural gradation from 
 man downward to half-men and apes. This has sometimes 
 been claimed, but the highest verdict opposes that claim. 
 
 There are links missing between man and his mammalian 
 predecessors. Here is the prototype of the great gap between 
 
THE HUMAN FACTOR. 305 
 
 man and his contemporaries. From the ape, from the horse, 
 the deer, and other living types, we trace, through fossil 
 bones, a graduation downward in rank," and backward in time, 
 to the organisms which made their advent at the beginning of 
 the Tertiary. Here is a pretty complete chain of being in 
 each case, from a primitive extiuct form, down quite to the 
 living form. But not so with man. The chain is broken 
 the links are lost. We can not explain this at present. As 
 long as the interval remains, we can not affirm from facts that 
 man is the outcome of ordinary evolution. 
 
 Thus we learn that man's organism is bound up with the 
 history of the material world. Inorganic conditions have 
 always circumscribed his existence. He could only appear 
 when they permitted; he can only dwell where they fit his 
 nature. The inorganic matter of the world has afforded 
 material for the embodiment of his soul. The lime in his 
 bones is as old as Eozoon. Venerable old house is that which 
 he has built for his dwelling place inconceivably more ven- 
 erable than the temples reared of the stones of the old pyra- 
 mids. He is made of the same stuff as the mountains and 
 the stars. He can survey the material universe and feel that 
 he is a part of it; and that the substance of his frame dates 
 back to a burning planet, to whirling rings of vapor and 
 glowing fire-mist. With the organic history of the world he 
 stands inseparably connected. He is the outcome of all ver- 
 tebrate progress ; he was embodied in its evolution as the fruit 
 and flower in the growing stem. Man can stand up among the 
 animals and feel a kinship with all of them. He can rationally 
 sympathize with them and concern himself in their well being. 
 
 In the survey of the plans of nature exemplified even in 
 his own being, he discovers in himself a revelation of mind. 
 Plan reveals the mind of a planner. That which rethinks 
 the thought embodied in a plan, must also be mind. Man 
 understands, to some extent, the plans embodied in the struc- 
 ture and history of the world. Man, therefore, in the study 
 of material nature, arrives at a knowledge of something which 
 is superior to matter ; he discovers spirit. 
 
 26 
 
306 WALKS AND TALKS. 
 
 . MIND IN 
 
 THE INTERPRETATION OF NATURE. 
 
 Two little round seeds lie on the table before me. They 
 seem to be exactly alike in every respect ; but they came from 
 two different packages, and were labeled by different names. 
 What is there about them which makes them different? I 
 plant the two seeds, and one grows to a stout ' ' mustard tree," 
 and the other to a field-turnip. Assuredly, with this differ- 
 ence of outcome, there was a fundamental difference in nature. 
 As 'that difference was not in the material, or the form of the 
 material, there was something not in the material in which the 
 essential difference resided. 
 
 The ova of two animals say the elephant and the rhi- 
 noceros are both simple nucleated cells. To the unaided 
 eye, no difference is discoverable. Subject them to chemical 
 analysis, and they are found composed of the same elements 
 combined in the same way. Treat them with reagents and 
 put them under the compound microscope, and nothing is 
 seen in one which does not appear in the other. In their 
 matter, in their form, they are absolutely undistinguishable. 
 Materially they are the same. But one develops, out of itself, 
 the embryo of an elephant, and the other, out of itself, the 
 embryo of a rhinoceros. On these two different embryonic 
 foundations the two different animals in their completeness are 
 built up. Thus, with no difference in the matter, there ex- 
 isted in the two germs, a profound difference in nature and 
 destiny. Beyond any thing scrutable, existed something in- 
 scrutable which controlled the development. That which was 
 not matter gave to matter a destination from which it could 
 not swerve. 
 
 A human organism with all its parts perfect, and all its 
 parts in harmonious action, is a splendid mechanism which 
 can never cease to awaken admiration and wonder. While 
 we contemplate it alas, its activities cease. A powerful cur- 
 rent of electricity has passed through the frame, and life is 
 extinct. The change which we witness is appalling. The eye 
 
MIND IN MATTER. 307 
 
 has lost its light; the voice gives forth no more intelligence; 
 the muscles cease to grasp the implement; the fabric of a man 
 now lies prone, motionless, speechless, insensible, dead a stu- 
 pendous and total change. But what is changed? Not the 
 mechanism. The heart is still in its place, with all its valves ; 
 the brain shows no lesion ; the muscles are all ready to act ; 
 every part remains as it was in life. Neither chemistry nor 
 the microscope detects, as yet, a material change. But some- 
 thing has gone out of the mechanism, for it is not as it was 
 something inscrutable, but yet something which ruled the 
 mechanism sustaining its action, lighting the eye, giving, in- 
 formation to the tongue, making of this machinery absolutely 
 all that which led us to say, "Here is a man." The man has 
 gone out and left only his silent workshop behind.. 
 
 Consider the life-powers in action. The organism is in 
 process of growth. A common fund of assimilative material 
 is provided by the digestive organs. Out of this, atom by 
 atom is selected and built into the various tissue-fabrics. Here 
 such atoms are selected as the formation of bone requires ; 
 there, the atoms suited for nerve or brain-structure; in an- 
 other place, the material of which muscles are made. If, un- 
 fortunately, the lime should be brought to be worked up in 
 the muscle-factory, or the nerve-stuff to be made into bone, 
 the whole organism would be thrown into disorder. Nice 
 selection of material is indispensable. Then notice the build- 
 ing of the bones. In one place the framework is so laid that 
 the filling up will result in a flat bone. It is to be a shoulder 
 blade, or a portion of the skull. In another place the frame- 
 work is elongated ; it is to be a long bone. The humerus is 
 never built into the skull, nor the shoulder-blade into the sole 
 of the foot. Every bone is constructed for its place and its 
 function. The whole system of bones, moreover, is conformed 
 to a definite fundamental plan of structure it is according to 
 the plan of a vertebrate. Now, selection of appropriate ma- 
 terial is an act of intelligence. The determination of one 
 form of structure rather than another implies discriminating 
 intelligence and executive will. The conformation of the total 
 
308 WALKS AND TALKS. 
 
 system of structures in the organism to an ideal plan implies 
 first, a conception of the plan ; secondly, a perception of fit- 
 ness between the plan and each particular tissue in process of 
 formation. Certainly, we must say that here mind is at work. 
 But is it the mind of the animal or plant ? Every person can 
 answer for himself whether he made his own bones. The 
 question is absurd. Is the mind evinced possessed by the 
 matter? Do these atoms and molecules move and arrange 
 themselves by an intelligence and choice of their own? Has 
 each one a conception of the plan to which they so consen- 
 taneously work ? Do they intelligently maintain the processes 
 of digestion, blood-purification, assimilation, and tissue-building? 
 How do they conceive, think, and will without brain ? How 
 select without eyes or hands? Who ever knew intelligence 
 acting without brain? But, it is conceivable, you say. Yes, 
 though it is not a brainless molecule. There is intelligence 
 acting in the organism, which does not belong to the matter 
 or the individual; whose intelligence is it? Intelligence is an 
 attribute ; it belongs to being ; it does not act abstracted from 
 being. What being then, acts in the living organism ? It is 
 the Omnipresent Being. 
 
 We need not restrict our consideration to the subtleties of 
 physiological action ; the fall of an apple teaches the same 
 thing. You say the attraction of the earth causes the apple 
 to fall. Good, but what is the attraction of the earth? Do 
 you mean that the earth possesses the attribute of attraction, 
 and exercises that attribute across the distance which separates 
 it from the apple? I think that is what most people mean by 
 attraction. But will you now explain how the earth as a 
 cause produces an effect in the apple a place where the cause 
 is not? Must not the cause of an effect be present in place 
 as well as time ? Either there is some medium intervening 
 between the earth and apple, through which the earth trans- 
 mits its action on the apple, or the downward pull comes 
 from some other source, and the presence of the earth is only 
 the occasion on which the pull is exerted. Which alternative 
 will you adopt? 
 
MIND IN MATTEK. 309 
 
 You say you will admit that the earth exerts an active 
 power through a medium. What ground have you to claim 
 that any active power is possessed by the earth? Have you 
 ever known a stone or a stick or a chunk of ice to exert any 
 active agency except this hypothetical agency of attraction? 
 You think you have often seen matter put forth activities of 
 its own ; but really you have only seen activities exerted in 
 connection with matter just as you observe selection and 
 choice in the working organism. Now in reality, all you 
 know about the origin and seat of efficient power is given you 
 in your own consciousness when you exert power ; and what 
 you infer from analogy when power seems to be exerted by 
 other persons. That is, you only know that efficiency origi- 
 nates in will your own will; and when you see efficiency 
 exerted anywhere, you can only affirm that some wiU is acting. 
 
 Now, are you prepared to ascribe such will to the earth, 
 to stones and mud and chunks of ice, when the so-called at- 
 traction seems to be exerted by them ? This is the same ques- 
 tion which has settled itself in the negative. The downward 
 pull on the apple comes, then, from some other source. This 
 is the other alternative. It means that power is exerted on 
 the apple, and on all things, causing them to tend together 
 in a certain fashion which we style the law of gravitation. 
 Now, power is an attribute. It belongs to something; as it 
 proceeds from will, power and will together are attributes of 
 being. Manifestly, that being is omnipresent, for attraction 
 is omnipresent. It is the Omnipresent Being. 
 
 Now let us glance at the principle of mechanical adapta- 
 tions. The heart has valves which open and close, and serve 
 the same ends as the valves in a pump. Do you think they 
 were intentionally so constructed and so placed, and so acted 
 on ? You have no doubt of it, you say ; neither have I. But 
 you perceive that if intention was present, mind was present to 
 understand the use and to perfect the adaptation. As before, 
 this implies a personal being, and a personal being present wher- 
 ever hearts are in process of formation, and wherever any 
 other design is going into effect. It must be, then, an Om- 
 
310 WALKS AND TALKS. 
 
 represent Being. This reasoning is so simple and so sponta- 
 neous that it has been held in high esteem ever since the epoch 
 of Aristotle. 
 
 But there are some persons who tell us that the design in a 
 pump is obvious, because we can fathom the mind which made 
 it; but the design of the pump in us, which does the same 
 work, can not be granted^ because we neither know who made 
 it, nor for what purpose it was made, nor whether there was 
 any purpose. This language seems very strange to an un- 
 sophisticated intelligence ; but human intuitions are not to be 
 balked by any such studied and presumptuous nonsense. I 
 set it down as a first principle of intelligence, that coordina- 
 tion in structure or action, implies intention. Finding things 
 so coordinated in nature for instance, the ball and socket of 
 a joint we feel inclined to affirm that they were intended to 
 serve as a joint ; and I believe they were. But suppose they 
 were not so intended ; these are structures most accurately 
 adjusted to each other that is not the result of chance. 
 There are not only the fitting shapes, but the ligament which 
 holds them together ; the investing membrane which incloses the 
 joint in a bag ; the sinovial fluid which lubricates it ; the solid 
 bosses on the bones, suitable for the attachment of muscles ; 
 the muscles capable of working the joint, and no end of other 
 structures all tributary to the action of the joint. If now, 
 after all, we pretend to complete ignorance of any use or ac- 
 tion designed in these structures, we can not possibly resist the 
 conviction that these various things came together through some 
 intention. Coordination of parts simply and alone regard- 
 less too, of the authorship implies intention. That is a prin- 
 ciple of the universal reason. To question it is to dispute 
 with the "multiplication table." 
 
 Glance next, at the prevalence of plans in the world. 
 There is the plan of vertebrate structure ; I have often made 
 mention of it. In the modification of the plan for beings so 
 diverse, with such different homes and native elements, and 
 instincts and functions, as those which have been formed, it 
 is wonderful that a simple conception should persist through all 
 
MIND IN MATTEE. 311 
 
 the ages of vertebrate history. It is an imperishable thought. 
 The Articulates present us another plan persistent for even a 
 longer period. The earth grew and attained completeness 
 according to a method. I have brought before your attention 
 the method of plant-making an astonishing history, which 
 correlates all our planets and satellites under one system. 
 There is the method of the movements of the planetary bodies. 
 Their paths are mathematical curves. There are other mathe- 
 matical relations existing among their distances, their periods, 
 their velocities. They are all swinging through vast irregu- 
 larities in their positions and movements; but these all pass 
 through cycles, and the old state is restored, showing that the 
 method of the planets is so all-comprehending and enduring 
 that seeming irregularities which continue for centuries, are 
 in fact but the fundamental features of a stupendous plan. 
 
 Now a plan is a mental concept, framed by reflection, and 
 coordinating things which are the objects of separate cognition. 
 In brief, plan is the product of thought; it is a demonstra- 
 tion of the existence and presence and activity of mind. If 
 the material worid is underlaid and pervaded and operated by 
 plan, method, law, then the world is a constant revelation of 
 a present intelligence, an omnipresent and omniscient Being. 
 
 There is one plan which underlies all other plans. In a 
 brief and condensed way, I have attempted to show that the 
 plans exemplified in organic life and the plans exemplified in 
 the formation of worlds, are only special exemplifications of 
 the all-embracing plan of evolution. Out of the infinite store- 
 house of possible plans under which the Supreme Power 
 might have proceeded in the origination of things, he has 
 chosen the method which we call evolution. This is a divine 
 choice. This sets forth a divine and eternal thought. This 
 embraces the world, the heavens, the universe, and every- 
 where proclaims the Mind which instituted it. This great 
 all-embracing, all-confronting, all-enduring fact inspires our 
 souls with awe ; it illuminates the dark realm of matter with 
 the sunlight of a divine revelation ; it moves our souls with a 
 sentiment of humble and profound adoration. 
 
312 WALKS AND TALKS. 
 
 Do not say the doctrine displaces the doctrine of divine 
 creation ; for it proclaims creation a perpetual creation ac- 
 cording to an intelligible, God-chosen method. Do not say 
 that in recognizing the "reign of law" we displace personal 
 divine agency ; for the first principle in an intelligent divine 
 government must be order, regularity, uniformity. Do not 
 imagine that law and method are the cause of any thing ; or 
 that we can hold them to be causes. Natural law and method 
 are only modes or ways in which the divine creative Cause 
 chooses to act. Do not say on the other hand, that the 
 ascription of world-regulating law to a personal Will, is the 
 delivery of the world to the government of caprice. Caprice 
 results from the absence of mind. Law and mind are correla- 
 tive terms. 
 
 I must not claim your attention longer. Perhaps I have 
 penned some sentences which my younger readers will find 
 difficult ; but I hope you will all treasure the truth in these 
 sentences, and ponder over it; then, when a little older, you 
 will be enraptured, as I have been, with the richness and 
 depth and grandeur of the meaning which the divine hand 
 has written in the rocks and in the stars. 
 
 THE UNITY OF NATURE. 
 
 THROUGH my window I watch the paling of the evening 
 twilight, till a mild ray from a little star meets my eye. The 
 pensive hour awakens a train of thought. A tiny ray of star- 
 light whence comes it? What is it? What does it say to 
 me? My soul listens, and I hear starry responses: "I am 
 a tremor in the universal ether. I am the throb of a world 
 in flames. It swings on the farther verge of the abyss of 
 space, and launched me years ago on a wave of ether, to be 
 floated down to your dark planet and whisper a sublime truth 
 to your understanding. I have traveled ten score thousand 
 miles a second, but since I started your grand-parents first 
 saw the day. They have spent their toilsome lives, and the 
 
ONE EMPIHE. 313 
 
 third generation now meets me at the window. In the cold 
 realms of space I have watched starry specks, till, with nearer 
 approach, they grew into suns; and I have darted from their 
 effulgence into other realms of starlight and frost. I am a 
 flash of divine intelligence. I am a messenger from the Infi- 
 nite, I bring tidings of the immensity of creation, of the 
 recognition of one supreme authority among all the constella- 
 tions the unity of the vast empire which stretches as far as 
 light of star has flown or electric thought has pierced." 
 
 So I listened to the message of the starlight, and my 
 thoughts were stirred within me. They wandered through 
 the vast spaces of the silent worlds, and I saw them all 
 balanced on the invisible threads of gravitation the same 
 gravitation which drags the sands of the Cordilleras down to 
 the Gulf. I saw worlds in pairs and triples, waltzing about 
 a common center of gravity ; I traced the ellipses which they 
 make in space, and found their radii vectores describing equal 
 areas in equal times -just as the moon moves round the earth 
 and the earth around the sun. No new geometry no new 
 mechanics in the systems of Sirius or Aldebaran or Polaris. 
 I saw the same ethereal pulsations flash light into being in the 
 constellation Bootes, as in the flashing of a match in my 
 study. Capella and Vega and the Earth are islands in one 
 ocean and the same waves beat on all the shores. 
 
 My thoughts still fondly caressed the theme. They re- 
 called to me now the magical achievements of the spectro- 
 scope. What had the spectroscope done ? It had taken such 
 a ray of star-light as had come to me this evening, and become 
 its confidant. To it the little ray had recited more than to me. 
 It has revealed the fact that the orb which sent it on its way 
 was a globe of incandescent vapor. Another ray brought 
 tidings of a world beginning to liquefy ; and still another 
 bore a message which seems to mean that its parent orb is 
 approaching a stage of incrustation. These are familiar 
 thoughts to us who floated down the history of our own fire- 
 born planet. The confessions of a star seem a reminiscence 
 of the earth's infancy. What has the spectroscope further 
 
 27 
 
314 WALKS AND TALKS. 
 
 done? It listened further to the revelation of the star-light. 
 It learned that the same world-stuff pervades the starry spaces 
 and the precincts of our planetary home. Iron is in the 
 stars and bolts the universe together in one inseparable unity. 
 Sodium is there, and hydrogen and other substances which 
 identify the stars and the earth. The very mud in our streets 
 is lighted up in the constellations. Sunlight tells the spectro- 
 scope a fuller tale. It writes the names of twenty elements, 
 at least, with which we have toyed in the laboratory, and un- 
 folds a marvelous story of warring flames and bristling fire- 
 darts streaming a million of miles from the lambent surface 
 of the sphere. 
 
 Thought wandered again across the wild courses of the 
 meteors. They awakened recollections of the iron and stones 
 which have come to the earth ; and of the carbon and hydro- 
 gen and watery vapor which they have brought to us from 
 beyond the planets. These falling stones have come as actual 
 samples out of the store-house of world-stuff. They verify 
 the revelations of the light. They come as slow-traveling mes- 
 sengers to confirm and amplify tidings flashed by telegraph. 
 They proclaim one sort of matter throughout the empire vast 
 as the limits of human vision. 
 
 Next, passed before memory's view, a grand procession of 
 events. Nebulous matter emerged from non-existence, and 
 subjected itself to the workings of gravitation and heat and 
 mechanics, till a succession of worlds rolled out on the plat- 
 form of existence, and I saw myself a circumstance in the 
 midst of the cosmic unfolding. I marveled that the energies 
 of Nature had not been exhausted, or replaced, in the seonic 
 labors which they performed in molding a system of planets 
 and marshaling them in their places. But I find that gravi- 
 tation and heat have worked under the same laws from the 
 beginning to the end. The unity of the physical world is as 
 vast and as wonderful viewed in its historical relations as in 
 its spatial extent. Down through all the cycles through all 
 the burnings and freezings through disruptions and collisions 
 through cataclysms of fire and flood, one hand has steadied 
 
ONE EMPIRE. . 315 
 
 the grand movement, and held it close to the plan which One 
 Intelligence ordained and One Will perpetuated. 
 
 Such a train of reflections is awakened by the arrival of a 
 ray of evening star-light. But our memories are stocked, I 
 think, with information which bears our thoughts along other 
 lines. We have seen how man's organization is bound up 
 with the constitution and the history of the world. We know 
 that man, in his own person, is the link which binds together 
 the beginning and the end of geological history. In his 
 material substance, he is a part of the material world. In 
 his plan of structure he is brother of the entire sub-kingdom 
 of Vertebrates. In the basis of his life he asserts kinship 
 with all that lives or has ever lived. He can stand erect in 
 the vast and majestic realm of nature and say, I am a part 
 of it. I am bound up with it not with the earth and moon 
 alone, but with the stars. Their vicissitudes are my personal 
 concern. I am made of world-stuff. The soul which swells 
 within me, and seizes on the meaning of the forms of Nature 
 that unites me with the invisible and eternal. 
 
 We note another aspect of the unity of nature. Not 
 alone the unity of things in themselves, but the unity of 
 things with each other. Plant life dawned as soon as the tur- 
 moil of the primitive ocean had subsided. Humble animal 
 forms rose above the horizon of being as soon as a place in 
 the world had been prepared for them. As conditions im- 
 proved organization slowly climbed the ladder of gradations, 
 on whose topmost round man stands erect and regal. Through- 
 out the history of life, the relations between organic and in- 
 organic nature have been reciprocal and responsive insomuch 
 that a careless logic has held the organism to be the result of 
 its environment. 
 
 Observe also, the correlation between the world and intel- 
 ligence. The capacity of knowledge exists in the presence of 
 something to know. And the objects of knowledge are acces- 
 sible to the knowing faculty. With the knowable and the 
 knowing faculty confronting each other, the pleasure of 
 knowing also stimulates the knowing faculty to exercise, and 
 
316 WALKS ASTO TALKS. 
 
 thus fulfills the manifest end of its existence, and fulfills a 
 clear mandate incorporated in the being of man, to seek for 
 knowledge. The correlations between the world and psychical 
 natures impress us in the commonest observations. How 
 true are the instincts of men and animals to something which 
 is real. The tadpole absorbs its gills and pushes out upon the 
 shore taking advantage of a fall of rain and ventures trust- 
 fully on the land, believing that a suitable home will be 
 found. Nor is the trust betrayed. The mother fowl calls her 
 new-born chicks, and they already know her voice. The 
 hungry babe cries out in the night, and Nature has responded 
 beforehand to the call. The intellectual instincts find the 
 realities of nature equally responsive. What intuition tells us 
 may be trusted. It is a voice implanted in my nature; it 
 speaks for the author of my being; it is the voice of God. 
 
 One kind of intelligence takes hold of the knowable. In 
 the mind which conceived the plan and frame of the universe 
 was an apprehension of the mathematical relations of the 
 magnitudes involved. The plan of the solar system in its 
 co-existent parts, and in its progressive creation was a thought 
 in the mind of the Originator. Man, so far as he grasps it, 
 rethinks the thoughts "of the Supreme Thinker. To seek 
 knowledge is to aspire to reproduce the thoughts of the divine 
 mind. So far as man thinks the divine thoughts, he possesses 
 a faculty akin to the divine intelligence ; so far he partakes of 
 the divine nature ; so far he comes into a sympathetic union 
 with the Being whose existence is before all and beyond all. 
 I believe, too, that all intelligences whether dwellers in an 
 angelic realm or on other planets, whether inhabitants of our 
 system or other systems, understand the truths of nature as 
 we understand them. There is but one geometry; there is 
 but one body of transcendental philosophy. In these we find 
 the common thoughts and the common language of universal 
 intelligence. In the unity of intelligence we find a bond of 
 brotherhood and sympathy between the dwellers in distant 
 worlds and between all and the Supreme Intelligence. 
 
 The unity of man's corporeal organism with the funda- 
 
ONE EMPIEE. 317 
 
 mental plan of vertebrate organization, and with the more fun- 
 damental plan of animal organization, is an instructive fact to 
 which our attention has more than once been drawn. But it 
 does not surpass in interest the unity of mankind in the basal 
 attributes of a moral and religious nature. It is vain to dis- 
 pute the possession of a nature essentially religious, by even 
 the lowest tribes of humanity. One common aspiration stirs 
 every human soul to accommodate itself to the Supreme 
 Being whose existence it feels, or more explicitly understands, 
 and whose authority it unhesitatingly recognizes. While this 
 common religious nature expresses the unity of mankind, it 
 has also a higher significance. The correlative of the religious 
 consciousness is God. Man and his Creator, therefore, con- 
 stitute one system a complete system, the unity of which is 
 expressed in a body of reciprocal relations between God and 
 man. The unity of the realm of nature is proven, as we see, 
 to the understanding by the phenomena and the history of 
 nature ; but without proof, every man holds intuitively to the 
 unity of nature ; every man firmly believes it. As the demon- 
 strated unity of nature implies one original Planner and one 
 Supreme Ruler; so this truth, here made known as an infer- 
 ence from facts of observation, is identical with the intuition 
 of the Unity of God revealed in the universal consciousness 
 of man. 
 
 Now John and Jennie George and Julia John's mother 
 and aunt and every body that has been with us through these 
 Talks it is time for us to take a vacation. I fear several of 
 the last Talks have been rather hard for some of you, as the 
 thoughts are too grand to level down ; but I could never for- 
 give myself, had I omitted them, for they seem to me to be 
 the ripe fruit, while all the rest is the mere stem and branches 
 on which the crop of fruit is developed. I think some of my 
 readers will be glad to get this fruit, and I am sure that John 
 and Jennie will keenly relish it as soon as their appetites are 
 a little more matured. 
 
I. SYNOPTICAL VIEW 
 
 OF THE 
 
 Classification of Plants and Animals. 
 
 I. PLANTS. 
 
 Series I. Cryptogams. 
 Stem I. THALLOPHYTES. CLASSES: ALG^E, FUNGI, LICHENS. 
 Stem II. BRYOPHYTES. ORDERS: LIVERWORTS, MOSSES. 
 
 Stem III. PTERIDOPHYTES. CLASSES: FERNS; CALAMARIANS, in- 
 cluding Horsetails and Calamites ; LYCOPODIACEANS, in- 
 cluding Lycopodids (p. 245), Lepidodendrids (pp. 174, 245), 
 and Sigillarids (pp. 174, 245). 
 
 Series II. Phanerogams. 
 
 Stem IV. GYMNOSPERMS, seeds not inclosed. Including the ORDERS: 
 CYCADS (p. 246), and CONIFERS. 
 
 Stem . ANGIOSPERMS, seeds inclosed. Including the CLASSES: 
 MONOCOTYLEDONS or Endogens and DICOTYLEDONS or 
 Exogens. 
 
 II. ANIMALS. 
 
 Stem I. PROTOZOANS, including the ORDERS: FORAMINIPERS, to which 
 belong Globigerina (pp. 59, 168), and Eozoon (p. 199) ; LOBOSA 
 which includes Amoeba (p. 200). 
 
 Stem II. C(ELENTERATES, including the CLASSES: SPONGES, ANTHO- 
 ZOANS, including all true coral-animals (p. 181). 
 
 Stem III. ECHINODERMS, with the CLASS CRINOIDS containing the 
 ORDERS: EUCRINOIDS (pp. 193, 234, 242), CYSTOIDS (p. 190), 
 and BLASTOIDS. 
 
 Stem l. WORMS, including Scolithus. 
 
 (319) 
 
320 SYNOPTICAL VIEW. 
 
 Stem V. MOLLUSCS, with CLASSES: BRYOZOANS, BRACHIOPODS 
 (pp. 182, 193, 234), LAMELLIBRANCHS (pp. 234, 193), GAS- 
 TEROPODS (pp. 195, 234), CEPHALOPODS (p. 187). 
 
 Stem VI. ARTHROPODS, with CLASSES: CRUSTACEANS, including OR- 
 DERS: TRILOBITES (p. 191), and MEROSTOMES (p. 239); 
 ARACHNIDS (p. 178), MYRIAPODS (p. 178) and INSECTS. 
 
 Stem VII. VERTEBRATES. 
 
 CLASS I. FISHES, with ORDERS: TELEOSTEANS common bony 
 Fishes; GANOIDS (p. 236), PLACODERMS (pp. 183, 236), ELAS- 
 MOBRANCHS, including Sharks and Rays. 
 
 CLASS II. AMPHIBIANS (p. 176), with ORDERS:. URODELES. Sal- 
 amanders ; BATRACHIANS, Frogs and Toads ; ^ABYRINTHO- 
 DONTS (pp. 177, 247). 
 
 CLASS III. REPTILES (p. 260), with ORDERS: CHELONIANS, Tur- 
 tles; PLESIOSAURS (p. 251), LIZARDS; PYTHONOMORPHS, Sea 
 Serpents; SERPENTS; ICHTHYOSAURS (p. 251), CROCODILIANS 
 (p. 248) ; PTEROSAURS (p. 257) ; DEINOSAURS (pp. 247, 251). 
 
 CLASS IV. BIRDS, with Sub- Classes; Toothed Birds (p. 261); 
 Jtunning Birds (p. 262) ; and Flying &irds (p. 262). 
 
 CLASS V. MAMMALS, with Sub- Classes: Ornithodelphs ; J>i- 
 
 delphs (p. 252); and Monodelphs, including ORDERS: EDEN- 
 TATES (p. 285) ; SIRENIANS, Manatee ; CETACEANS, Whales, 
 Dolphins, Zeuglodon (p. 165) ; HYRACOIDS ; PROBOSCIDIANS 
 (p. 156) ; AMBLYPODA, embracing Dinoceras (p. 256), Uinta- 
 therium (p. 257), Coryphodon (p. 256) ; CLINODACTYLA, in- 
 cluding Rhinoceros (p. 257). Tapir (p. 257), Rrontotherium 
 (p. 257), Horse (pp. 256 263) ; Hippopotamus, Oreodon 
 (p. 257); Camel, Sheep. Ox; TILLODONTS, Tillotherium 
 (p. 256) ; CARNIVORES, including Pinnipeds, Seals, Planti- 
 grades (p. 255), Digitigrades (pp. 255, 257); RODENTS, 
 CHEIROPTERS, INSECTIVORES, Moles ; QUADRUMANES, with 
 suborders: Lemurs, Tailed Monkeys, Anthropoids; Bi- 
 MANES, Man. 
 
CITATIONS AND OTHER WORKS. 321 
 
 II. Citations for Further Information. 
 
 The Author believes it may be of service to the reader to indi- 
 cate portions of his own writings in which subjects lightly touched 
 in this book may be found further elucidated. The works in the 
 appended list are cited by the numbers prefixed. 
 
 1. For graphical illustrations of the general subject, see espe- 
 cially II ; but also III, IV and V. 
 
 2. Rudimentary guide to systematic study, I. 
 
 3. Ampler guide to systematic study, II. 
 
 4. Fuller and more scientific treatment of theoretical portions 
 of the general subject, III. 
 
 5. Popular descriptions with delineations of terrestrial history 
 yet future, V. 
 
 6. Glacial phenomena and scenery, IV. 
 
 7. Something fuller on prehistoric man, V, VI. Also Mc- 
 Clintock and Strong's Cyclopaedia, Article "Preadamites." 
 
 8. Ethnology, homes, and migrations of early peoples, VI. 
 
 9. The relations of religion and intelligence, VIII, IV. 
 
 10. Synopsis of world-theories of Kant, Laplace, Herschel, and 
 others, III, Part IV. 
 
 11. The Doctrine of Evolution, VII, IV. But more especially, 
 Encyclopedia Britannica, American Reprint, Supplement, Article 
 " Darwinism ;" also, McClintock and Strong's Cyclopaedia, Supple- 
 ment, Article, " Evolution." 
 
 III. Other Works by the Author of this Book. 
 
 I. Geological Excursions, or the Rudiments of Geology for 
 
 young Learners, 234 pp. 88 cuts. Griggs & Co., Chicago. 
 
 II. Geological studies, or Elements of Geology for High 
 Schools, Colleges, Normal and other Schools. Part I. Geology In- 
 ductively Presented. Part II. Geology Treated Systematically, 
 about 500 pp. 367 Illustrations. Griggs & Co., Chicago. 
 
 III. World-I4fe or Comparative Geology, pp. xxiv-f-642. 
 59 illustrations. S. C. Griggs & Co., Chicago. 
 
 IV. Sparks from a Geologist's Hammer, pp. 400, with 
 10 illustrations. Griggs & Co. 
 
OTHER WORKS. 
 
 V. Sketches of Creation, a Popular View of some of the 
 Grand Conclusions of the Sciences in reference to the History of 
 Matter and of Life ; together with a statement of the Intimations of 
 Science respecting the Primordial Condition and Ultimate Destiny 
 of the Earth and the Solar System. Pp. xii+459 with 101 illustra- 
 tions. Harper & Brothers, New York. 
 
 VI. Preadamites, or a Demonstration of the Existence of 
 Men before Adam. Together with a study of their Condition, An- 
 tiquity, Kacial Affinities, and progressive Dispersion over the 
 Earth. With Charts and other illustrations, 8vo, pp. xxvi+500. 
 Griggs & Co., Chicago. 
 
 VII. The Doctrine of Evolution. Its Data, its Principles, 
 its Speculations, and its Theistic Bearings, pp. 148. Harper & 
 Brothers, New York. 
 
 VIII. Reconcilation of Science and Religion. Pp. 
 
 xvi+403. Harper & Brothers, and Phillips^ Hunt, New York. 
 
INDKX. 
 
 Aar, torrent of, 45. 
 
 Abbott, C. C. on early man, 282. 
 
 Abyss of the ocean, 58 ; receives little 
 sediment, 66. 
 
 Acervularia, 181. 
 
 Acids in the air, 224. 
 
 Adirondacks, features of, 108. 
 
 Mtna, Mount, 87 seq.', eruptions of, 88. 
 
 Agassiz and Drift, 15, 45. 
 
 Age of the world, 288, seq. 
 
 Ages of man, 284. 
 
 Air-breathers of Coal period, 175, 245. 
 
 Alaskan mammoth, 158. 
 
 Amoaba, 200. 
 
 Amphibians, reign of, 72; characters 
 of, 176; diminution of, 247 ; a com- 
 prehensive type, 259. 
 
 Andrews, E. on Geologic time, 292. 
 
 Ant-eater, Banded, 252. 
 
 Anthracite, 151. 
 
 Anticipation in organic structures, 
 258. 
 
 Anticlinal explained, 76, 77; in oil 
 accumulation, 137. 
 
 Aphanite, 40. 
 
 Appalachian region, 267. 
 
 Appalachians, origin of, 246. 
 
 Archseopteryx, 261. 
 
 Archegosaurus, 247. 
 
 Argillite, 40 ; primitive, 225. 
 
 Argonauta, 185. 
 
 Artesian wells, 96,70; bored for salt, 132. 
 
 Assortment of sediments, 46, 187. 
 
 August meteors, 211. 
 
 Azoic seon, 230. 
 
 Bad Lands, 55; fossils of, 162 seq.; 
 
 description of, 162. 
 Ball, R. 8., on primitive tides, 232. 
 Bar of Mississippi, 49. 
 Basaltic columns, 94. 
 Basin of a geyser, 81. 
 Basin Province, 267. 
 Basins of Great Lakes, 279. 
 Beaches, ancient, of lakes, 41 ; of sea 
 
 shore, 275, 276. 
 
 Becker, G. P., on Comslock lode, 123. 
 
 Bedded, thin or thick, 63. 
 
 Belodon, 248. 
 
 Bilateral symmetry, 193. 
 
 Birds, reptilian, 252, 260, 261; gene- 
 alogy of, 262. 
 
 Bituminous coal, 152. 
 
 Bog iron ore, 35, 126, 128. 
 
 Bonanza defined, 120. 
 
 Bowlders described, 13 ; enormous ex- 
 amples of, 16; most abundant 
 northward, 17; sources of, 17, 18; 
 direction of transportation of, 21, 
 23. 
 
 Bowlder clay, 20. 
 
 Brachiopods, 189, 193, 234, 242. 
 
 Brains of early mammals, 254. 
 
 Brandon frozen soil, 99. 
 
 Brontotheriurn, 257. 
 
 Brontozoum, 248. 
 
 Brown coal, 153. 
 
 Burns gas well, 145. 
 
 Caenozoic, Great System, 78; 
 
 Times, 252 seq.; mammals, 254 teq. 
 Caking coal, 152. 
 Calabrian earthquakes, 103, 104. 
 Cambrian, System, 72 ; fossils, 190 seq.; 
 
 rocks, 192, 196. 
 
 Cannel coal, 152 ; formation qf , 246. 
 Cafions, result of erosion, 54. 
 Carbonic acid, in the air, 243 ; removal 
 
 of, 244. 
 Carboniferous System, 72; fossils, 173 
 
 seq.; Age, 241. 
 Carinate birds, 262, 298. 
 Caspian Sea and salt, 130 seq. 
 Cat family, 297. 
 Catskill Mts. described, 54. 
 Caucasus, buried ice in, 99. 
 Caverns for human homes, 284. 
 Cement of teeth, 155. 
 Centrifugal tendencies, 215, 216. 
 Centripetal tendencies, 215. 
 Cephalaspis, 238, 239. 
 Cestraciont sharks, 236, 238. 
 
 (323) 
 
324 
 
 INDEX. 
 
 Chalk, 169. 
 
 Chambered shells, 184, seq., 242. 
 
 Chamonix glaciers, 26. 
 
 Cham plain epoch, 275 seq. 
 
 Cheirotherium, 177. 
 
 Chimney of a geyser, 81. 
 
 Cincinnati, geological situation of, 76. 
 
 Classification of strata, 67, 71, 72. 
 
 Clay beds in the Drift, 31, 32, 33. 
 
 Clay iron stones, 129. 
 
 Coal, geology of, 149 seq,, 241 ; origin 
 
 of, 149, 241. 
 Coal measures, 141 ; fossils of, 173, seq ; 
 
 of Cretaceous age, 172; of Jurassic 
 
 age, 250. 
 
 Coal period, scenes from, 241. 
 Cobble-stones, 13. 
 
 Coleridge, on Chamonix glaciers, 27. 
 Columnar lava, 94. 
 Comets, 208; nature of, 210; not 
 
 natives of our system, 210. 
 Comprehensive types, 254, 258 seq. 
 Comstock Lode, heat on, 98 ; mining 
 
 on, 119 ; geology of, 119. 
 Concretions of ore, 129. 
 Condensation of first water, 222. 
 Cone of geyser, 83. 
 Cone, volcanic, origin of, 90. 
 Conglomerate, 37; notable examples 
 
 of, 37, 38 ; Carbon i ferous, 243. 
 Continent-building, 264 seq. 
 Continuity, a principle in nature, 294. 
 Contraction of earth, 115, 227 
 Cooling earth, 110, 115, 203, 204, 219 seq., 
 
 289. 
 
 Cooling of sun, 289. 
 Cope, E. D , on fossil mammals, 166, 
 
 253; on reptiles, 172. 
 Copper as a bowlder, 18. 
 Coral animals, 235. 
 
 Cordilleran Land, 233, 235, 265; subsi- 
 dence of, 265, 266. 
 Corniferous fishes, 237. 
 Coryphodon, 256. 
 Coseguina, eruption of, 89. 
 Cosmic dust, 60, 211. 
 Cretaceous mammal, 253. 
 Crevasse, the Grand, 25. 
 Crevasses, Forbes on, 28 ; phenomena 
 
 of, 28. 
 
 Crinoids, 189, 234. 
 Crinoids in deep sea, 61. 
 Croll on geological climates, 290. 
 Crustaceans, 92. 
 Crust of the earth, 220 eq.; rugged 
 
 character of primitive, 221; thick- 
 ened by sediments, 228 ; melted off 
 below, 229. 
 
 Cycads, 246. 
 
 Cystids, 190. 
 
 Darkness on the deep, 222. 
 
 Day after primeval darkness, 223. 
 
 Dawson, G. M., on bowlders, 16. 
 
 Deep sea, 58, 169. 
 
 Degeneration of types, 254. 
 
 Delamater gas well, 145. 
 
 Deltas, 49. 
 
 Deluge of Noah, 69, 70. 
 
 Deposits of geysers, 83. 
 
 De Saussure on Mer de Glace, 27. 
 
 Devonian Age, 72; strata, 178 seq.; 
 fossils, 180 seq. 
 
 Differentiation 255. 
 
 Digitigrade, 255. 
 
 Dinichthys, 183. 
 
 Dinoceras, 256. 
 
 Dinosaurs, 247, 260. 
 
 Diorite, 39. 
 
 Dip of strata, 76. 
 
 Dolomite, primitive, 225. 
 
 Drift defined, 18; its constitution, 19; 
 its uses, 19; semi-stratified condi- 
 tion of, 20; causes of same, 21; a 
 northern phenomenon, 21 ; suited 
 to human wants, 33; soluble sub- 
 stances in, 34. 
 
 Drift in mining, 153. 
 
 Dromatherium, 252,254. 
 
 Dyke or Dike defined, 94. 
 
 Earthquakes, 102 ;motionsof, 102; 
 
 waves of, 103; kinds of, 103; causes 
 
 of, foci of, 106; connected with 
 
 action of springs, 108. 
 Eccentricity theory, 290. 
 Egg, immaterial force in, 306. 
 Elasmobranchs, 236, 238. 
 Embryological parallels, 299 
 Embryonic development, 296. 
 Emmons, E., and his work, 109. 
 Environment and organism, 71 seq. 
 Eozoic, 62,72; thickness of, 229, 231 ; 
 
 often at highest levels, 78; rocks, 
 
 197, 230 ; fossils, 199. 
 Eozoon, 199, 232. 
 Erosion, treated, 50; the source of 
 
 sediments, 51 ; wastes the land, 51 ; 
 
 in the Catskills,54; in Tennessee, 
 
 65; in the interior, 269 ; by glacier 
 
INDEX. 
 
 825 
 
 action, 272 ; as a measure of time, 
 291. 
 
 Eruptions, of Vesuvius, 86; JEtna, 
 87; Coseguina, 89; Kilauea, 90; 
 other volcanoes, 90. 
 
 Eureka mining district, 124. 
 
 Evolution, facts bearing on, 194 ; con- 
 sidered, 294 seq.; not atheistic, 206, 
 312; an all-embracing plan, 311. 
 
 Faults in mountains, 269. 
 
 Favosites, 181. 
 
 Feldspar described, 38, 39 ; primitive, 
 
 225. 
 
 Fern vegetation in coal, 150, 244. 
 Fiery teon, 202. 
 
 Finiteness of geological time, 84. 
 Fire damp, 141. 
 Firehole River, 81. 
 
 Fire-mist, 205 ; primordial, 205, 214, 219. 
 Firn, 22, 272. 
 Fishes, in deep sea, 61 ; reign of, 72, 
 
 178 ; fossil, 178 ; 183, 184, 236 ; lessons 
 
 from, 240. 
 
 Flint implements, 283. 
 Flood from glacier, 278. 
 Foci of earthquakes, 106. 
 Footprints in sandstone, 248. 
 Foot-wall in mining, 119. 
 Foraminitera, 199. 
 Forbes on Alpine glaciers, 28. 
 Formation, defined, 74 ; the oldest not 
 
 sedimentary, 74. 
 Fossils, 67 ; speculations on, 68. 
 Frumento, Monte, on JEtn&, 88. 
 
 Gangue in mining, 124. 
 
 Ganocephala, 260. 
 
 Ganoids, 230, 238 ; prophetic, 258, 259. 
 
 Garden of the gods, 55. 
 
 Gardiner's River, scenery of, 80. 
 
 Gardiner, 3., on Niagara Falls, 291. 
 
 Gar pikes, 240. 
 
 Gas, geology of, 138, 141 seq; localities 
 of, 141, 143, 144 ; composition of, 147; 
 value of, 147; source of, 148, perma- 
 nency of, 148. 
 
 Gasteropods, 189, 195. 
 
 Geological history, table of, 75. 
 
 Geology, where data of are found, 9, 10. 
 
 Geyerite, 81. 
 
 Geysers in National Park, 81 seq ; in 
 Iceland and New Zealand, 84; ex- 
 planation of, 84. 
 
 Giantess geyser, 82. 
 
 Gilbert, G. K., on laccoHtes, 95. 
 
 Glacier defined, 23 ; movements of, 28, 
 28, 29. 
 
 Glaciers continental, 270 seq.; inva- 
 sion of, 271 ; pressure of and conse- 
 quences, 275 ; examples of, 279. 
 
 Glaciers of the Alps, description of, 
 24 ; movements of, 23, 28, 29 ; former 
 extension of, 29, 30. 
 
 Globigerina ooze, 59 ; in chalk, 168. 
 
 Gneiss, 39 ; syenitic, 39. 
 
 Goniatites, 242. 
 
 Gorge of Niagara, 277, 278 ; age of, 291. 
 
 Gould, S. Baring, on geysers, 84. 
 
 Grand crevasse, 25. 
 
 Grand Plateau, 25. 
 
 Granite described, 39; "Quincy," 89; 
 formation of, 231. 
 
 Granulite, 39. 
 
 Graptolites, 195. 
 
 Great Plains, 243, 266, 267, 269, 277. 
 
 Great Salt Lake, 269. 
 
 Groups of strata, 74. 
 
 Gypsum, geology of, 130. 
 
 Hadrosaur, 251. 
 
 Haematite, 126. 
 
 Hall, James, on Niagara Falls, 291. 
 
 Hanging wall in mining, 119. 
 
 Hard waters, 34. 
 
 Heat, internal, 84, 96 seq., 203 ; in ar- 
 tesian wells, 98 ; in mines, 98, 121 ; 
 in tunnels, 98; rate of increase of, 
 99, 100 ; theories of, 100 ; in deeper 
 rocks, 202. 
 
 Hesperornis, 261. 
 
 Hitchcock, C. H., on bowlders, 16, 17. 
 
 Hornblende, 39. 
 
 Horse in mining, 119. 
 
 Horse type in geology, 256, 263. 
 
 Hot Springs of National Park, 83. 
 
 Hugi, on motion of glaciers, 30. 
 
 Human relics, 283. 
 
 Humphreys and Abbot on Missis- 
 sippi, 292. 
 
 Hysenodon, 257. 
 
 Hyposyenite, 39. 
 
 Ice in the soil, 99; under lava, 100; 
 
 erupted with lava, 100. 
 Iceland, geysers of, 84. 
 Ichthyornis, 261. 
 Ichthyosaur, 251, 260. 
 Iguanodon, 251. 
 Illinois flooded, 43. 
 
326 
 
 INDEX. 
 
 Immaterial principle revealed, 306 seq 
 Insects of Coal Period, 245. 
 luterual heat, 84. 
 Inversion of strata, 78. 
 Invertebrates, reign of, 230 seq, 
 Iron and its geology, 125. 
 Iron in earth's center, 129. 
 
 Joggins, coal beds at, 177. 
 J upiter in his stormy stage, 224. 
 Jurassic mammals, 253. 
 
 Karaboghaz, Gulf of, 130. 
 Kazwini, opinions of, 69. 
 Kilauea, eruption of, 90 ; lava of, 221. 
 King Crab and his relatives, 190 seq. 
 Knox County gas, 142. 
 
 Labyrinthodonts.177,245, 247, 260. 
 
 Laccolites, 95. 
 
 Lacustrine deposits, 41. 
 
 Lffilaps, 251. 
 
 Lakelets, origin of, 280. 
 
 Lakes, Tertiary, 269. 
 
 Lakes the Great, floods of, 41 ; inun- 
 dation by, 42, 43. 
 
 Lamellibranchs, 193. 
 
 Laminae, 63. 
 
 Lamination, 63 ; oblique, 63. 
 
 Lands of primitive times, 233, 235. 
 
 Langford, N. P., on "Giantess gey- 
 ser," 82. 
 
 Langley, S. P., on solar heat, 212. 
 
 Lapilli, 86. 
 
 Laurentide Hills, 112. 
 
 Lava of Vesuvius, 85. 
 
 Lavas, ancient, 91; on Pacific slope, 
 92, 269, 275; in interior, 93; ages of 
 eruption of, 94, 269 ; Triassic, 250 ; 
 Tertiary, 269 ; Quaternary, 275, 281. 
 
 Lead mines, 124. 
 
 Leadville mining district, 124. 
 
 Lepidodendron, 174, 241, 245, 246, 247. 
 
 Lessons from fossil fishes, 240. 
 
 Levees, 49. 
 
 Lewis, H. C., on early man, 282. 
 
 Lewiston escarpment, 43. 
 
 Life, dawn of, 20 ; immaterial princi- 
 ple of, 307. 
 
 Limbs of vertebrates, 255, 301. 
 
 Limestone, 40; Devonian, 179; Silur- 
 ian, 186 ; how formed in primeval 
 ocean, 225. 
 
 Limonite, 126. 
 
 Limulus, 190. 
 
 Liugula, 192, 195, 234. 
 
 Links missing, 304. 
 
 Liquid earth, 220. 
 
 Lizards, 251, 261. 
 
 Lodes, 28. See " Comstock Lode." 
 
 Lodestoiie, 127. 
 
 Lost rocks, 14. 
 
 Machaerodus, 257. 
 Mackinac Island, 41. 
 Magnetite, 127. 
 Mallet, R., on earthquakes, 103. 
 
 Mammals, reign of, 73; extinct spe- 
 cies of, 154 seq., 162 seq. ; Triassic, 
 252; Jurassic, 253; in Bad Lands, 
 163 ; on Atlantic coast, 165 ; in Ala- 
 bama, 165 ; Cseuozoic, 254. 
 
 Mammoth, 155 ; Siberian, 156, 274, 284. 
 
 Mammoth Hot Springs, 83. 
 
 Man, reign of, 73 ; prophesied, 243, 302 ; 
 structural rank of, 255; in the 
 light of science 300 seq. ; limbs of, 
 302; birth place of, 302; the last 
 term, 303; a cosmopolite, 303; 
 marks a period, 304 ; advent of, re- 
 cent, 304 ; of geology not inferior, 
 304 ; revelation of mind, 305. 
 
 Man, primitive, advent of, 28 seq.; an- 
 tiquity of, 281, 286 ; a Mongoloid in 
 America, 282 ; and in Europe, 286, 
 304; a Glacial phenomenon, 282; 
 contemporaries of, 284 ; character- 
 istics of, 285. 
 
 Marine Invertebrates, reign of, 72. 
 
 Marl, 35. 
 
 Marsh, O. C., on fossil mammals, 166, 
 253 ; on fossil reptiles, 172. 
 
 Marshall Sandstone, 242. 
 
 Marshes, origin of, 48. 
 
 Mashing together of rocks, 116,117. 
 
 Mastodon, 155, 257. 
 
 Mauna Loa, eruption of, 90. 
 
 Mechanical adaptations, 309. 
 
 Megatherium, 159. 
 
 Meniscoessus, 254. 
 
 Menodus, 257. 
 
 Mesozoic, Great System, 72; events, 
 241 seq.; rocks and fossils, 167 seq.; 
 246 seq.; coal, 173; erosions, 267. 
 
 Metamorphism, 117, 118, 202, 231. 
 
 Metcalf, W., on Pittsburgh gas, 144. 
 
 Meteors, 210. 
 
 Method in nature, 207, 259, 263, 300, 
 301 ; the evidence of mind, 310. 
 
 Method of creation, 294 seq.; 306 seq. 
 
INDEX. 
 
 327 
 
 Mica described, 38. 
 
 Mica schist, 39. 
 
 Michigan salt, 132, 133; gas, 143. 
 
 Milwaukee bricks, 44. 
 
 Mind in physiological activities, 309; 
 
 in the method of nature, 311. 
 Minerals denned, 37. 
 Mines and mining, 119. 
 Mississippi River, sediments of, 48. 
 Mont Cenis Tunnel, 98. 
 Monti Rossi on ^tna, 88. 
 Monument Park, 55. 
 Moon, origin of, 219 ; tidal action of, 
 
 219, 232. 
 Moraine defined, 28; of continental 
 
 glacier, 273, 276. 
 Mosasaur, 171, 251. 
 Moss petrified, 35. 
 Mountains, structure of, 108 seq.; of 
 
 upheaval, 112, 227 ; erosion of, 112 ; 
 
 of relief, 113 ; formation of, 113, 246 ; 
 
 theories of, 114; trends of, 117; 
 
 thickness of strata in, 118; syn- 
 
 clinorium theory of, 118. 
 Mouths of great rivers, 49. 
 Mud from Vesuvius, 86. 
 Murraysville gas wells, 145, 147. 
 Mylodon, 159. 
 
 National Park described, 79 seq. 
 
 Nature, interpretation of, 306 seq. 
 
 Nautilus and its ancestry, 184 seq. 
 
 Nebulae, 213, 214 seq. 
 
 Nebular theory, 214 seq., 295. 
 
 Neff, Peter, and gas production, 142. 
 
 Nevada continent, 267. 
 
 Neve, 22, 272. 
 
 Newberry, J. S., on Table Mt. plants, 
 
 282. 
 
 New England reptiles, 248. 
 Niagara gorge, 43, 277 ; age of, 291. 
 Niagara Limestone, 186. 
 Nile delta, 292. 
 Northern Land of America, 233, 235, 
 
 264; uprising of, 266. 
 November meteors, 211. 
 
 Obelisk, New York, 39, 113. 
 
 Ocean depths, explored, 56 ; origin of 
 219 ; chemical war in 224 seq.; sedi- 
 mentation in, 228. 
 
 Odontornithes,261. 
 
 Oil. See "Petroleum." 
 
 Oil regions, 139. 
 
 Old Faithful geyser, 81, 82. 
 
 Oldham on Earthquakes, 104. 
 
 Old Red Sandstone, 184. 
 
 Onchus, oldest vertebrate, 238, 239, 301. 
 
 Ontogeny, 297. 
 
 Onychodus, 237, 239, 258, 301. 
 
 Oreodon, 257. 
 
 Ores of lead, 24 ; of iron, 35, 125 seq. 
 
 Orthoceras, 188, 194, 234. 
 
 Otozoum, 249, 250. 
 
 Outcrop defined, 67, 75. 
 
 Oysters in Cretaceous rocks, 171. 
 
 Ozark Range as an obstacle, 43. 
 
 Palaeaspis, 238. 
 
 Palaeozoic, Great System, 72; popu- 
 lations, 234. 
 
 Palmier! and earthquakes, 85. 
 
 Panama cliffs, 62. 
 
 Parameryx, 257. 
 
 Park, National, described, 79 seq. 
 
 Peat, 153. 
 
 Pebbles, 14. 
 
 Pelagic forms, 59. 
 
 Periods, 74. 
 
 Perrey on earthquakes, 105. 
 
 Petoskey, fossils at, 181. 
 
 Petroleum, geology of, 135; laws of 
 accumulation of, 136. 
 
 Pilot Knob, 128. 
 
 Pittsburgh gas, 144 ; production of, 146. 
 
 Placers, 96. 
 
 Placoderms, 236. 
 
 Plans in nature, 190, 301. See 
 "Method." 
 
 Plantigrade mammals, 255. 
 
 Plants, in coal beds, 50 ; of coal pe- 
 riod, 244; origin of, 216. 
 
 Plateau Province, 268, 269. 
 
 Plesiosaur, 251. 
 
 Ponds filling up, 47. 
 
 Porphyry, 40. 
 
 Potholes, 276. 
 
 Potsdam Sandstone, 111, 192, 196. 
 
 Prairies, origin of, 280. 
 
 Preadamites, question of, 287. 
 
 Precipitations, primeval, 225. 
 
 Prophetic types, 258. 
 
 Protozoans, reign of, 72. 
 
 Pteraspis, 238. 
 
 Pterichthys, 239. 
 
 Pterosaur, 251, 260. 
 
 Quartz, and its varieties, 87 ; primi- 
 tive, 226. 
 Quartzite, 37, 226. 
 
328 
 
 INDEX. 
 
 Quaternary, mammals, 164 teq.; 
 events in West, 269. 
 
 Rain, where does it go ? 30. 
 
 Ramsay on lake-basins, 279. 
 
 Recession, of Niagara Falls, 291; 
 Falls of St. Anthony, 292. 
 
 Reigns of extinct types, 72. 
 
 Relics of man, in river drift, 283; in 
 lakes, 283 ; on shores, 283 ; in bogs, 
 283. 
 
 Relief in mountain features, 54. 
 
 Reptile monarchy, 246. 
 
 Reptiles of Cretaceous time, 172; of 
 Mesozoic, 246 seq. ; diversification 
 of type of, 250; a comprehensive 
 type, 260. 
 
 Resolution of comprehensive types, 
 259. 
 
 Retrospection in organic types, 258. 
 
 Rhynchodus, 237. 
 
 River drifts, 283. 
 
 River terraces, 44. 
 
 Rocking stones, 16. 
 
 Rocks, kinds of, 35; how distin- 
 guished, 36. 
 
 Rocky Mountains lowered, 53 ; form- 
 ing, 267. 
 
 Rotation of earth retarded, 118. 
 
 Rotten limestone of Ala., 170. 
 
 Salt, geology of, 130; in sundry re- 
 gions, 132; impurities of, 133. 
 
 Sandstone, 40; red, of Connecticut 
 valley, 249. 
 
 Satellites, origin of, 218. 
 
 Saurians, 248 seq. 
 
 Schist, mica, 39 ; hornblende, 40. 
 
 Seaboard Land, 233, 243, 264. 
 
 Seaweeds, fossil, 187. 
 
 Sedimentation, 45; in ocean, 226, 228 ; 
 restricted to continental slopes, 228. 
 
 Sediments, assortment of , 46 ; filling 
 ponds, 47; in river waters, 48; 
 thinner under deep waters, 229 ; 
 transportation of, 50; on ocean 
 bottom, 57, 58. 
 
 Segregations of ore, 128. 
 
 Seracs, 25. 
 
 Shale, 40. 
 
 Sharks, 236. 
 
 Sherman, General, on "Old Faith- 
 ful,'' 82. 
 
 Shrinking of earth, 107. See "Con- 
 traction.'' 
 
 Siberian mammoth, 158. 
 
 Siderite, 129. 
 
 Sierra Nevada uplifted, 268. 
 
 Sigillaria, 174, 178, 241, 244, 245, 247. 
 
 Silurian 72; rocks, 185; fossils, 187 
 seq. 
 
 Sinter, silicious, 81. 
 
 Skaptar Jokul, eruption of, 90. 
 
 Smith, J. L., on gas wells, 145. 
 
 Soluble substances in Drift, 34. 
 
 Somma, on Vesuvius, 86, 91. 
 
 South American quadrupeds, 160; 
 continent, 265. 
 
 Spinal axis in man, 303. 
 
 Spirifera, 182. 
 
 Springs and wells, 31, 32; in Na- 
 tional Park, 81 seq. 
 
 St. Anthony, Falls of, 292, 293. 
 
 Stigmnria, 174. 
 
 St. Peters Sandstone, 196. 
 
 Storm, primeval, 222. 
 
 Strains from shrinkage, 107, 242, 250. 
 
 Strata, and classification, 62; exam- 
 ples of, 63, 64; formed by water, 
 64; not in deep sea, 65; oldest not 
 yet seen, 75 ; arrangement of, 75, 
 often in long folds, 78 ; situation 
 of newest, 79. 
 
 Stratified and unstratified, 39, 62. 
 
 Streams, sources of, 32. 
 
 Structure, geological explained, 75, 
 76,77. 
 
 Submergence of Quaternary, 275. 
 
 Subterranean waters, 30. 
 
 Succession of organic forms, 298. 
 
 Sugar Loaf, Mackinac, 42. 
 
 Sun, a remnant of fire-mist, 218. 
 
 Sun's heat in the soil, 97. 
 
 Sutro tunnel, 122. 
 
 Swamps, origin of, 48. 
 
 Swarms, meteoroidal, 213. 
 
 Syenite, 39 ; formation of, 231. 
 
 Symmetry, two kinds of, 193. 
 
 Synclinal explained, 76. 
 
 Systems of strata, 72, 73. 
 
 Table Mountains 95. 
 Table of geological history, 73. 
 Terminal moraines of continental 
 
 glaciers, 273 seq. 
 Terraces of lakes, 41 ; of rivers, 44, 278. 
 Tertiary mammals, 167. 
 Thickness of formations, 289. 
 Tides in primitive history of earth, 219 
 
 seq, 232 ; in reptilian age, 249. 
 
INDEX. 
 
 329 
 
 Till defined, 20, 277, 282. 
 Tillotherium, 256. 
 Time, geological, 288. 
 Tinoceras, 257. 
 Torrential action, 21. 
 Tracks in sandstone, 248, 249. 
 Translation, earthquake of, 106. 
 Transportation of Drift, 15. 
 Trap eruptions in Trias, 250. 
 Travertin, 35 ; deposited by geysers, 83. 
 Trends of mountain axes, 118. 
 Triassic, lavas, 94; sandstones, 172; 
 
 mammals, 252. 
 
 Trilobites, 191 ; Cambrian, 234. 
 Tube of a geyser, 82. 
 Tufa, 35. 
 
 Ulnta Mountains upraised, 268. 
 
 Uintatherium, 257. 
 
 Unity of nature, 312 ; evinced in light, 
 313; in planetary laws, 313; in 
 world stuff, 314; in unity of de- 
 velopment, 315 ; in relations of man 
 and nature, 316; in mental and 
 moral faculties, 316; in relations 
 of man and God, 317. 
 
 Uplifts of strata, 116. 
 
 Vapor denned, 204. 
 Vegetation of coal beds, 150, 174; of 
 Cretaceous, 170; of Eozoic, 232. 
 
 Veins of ores, 128. 
 
 Vertebrates, earliest, 236; limbs of, 
 255. 
 
 Vesuvius, 83 ; eruptions of, 87. 
 
 Vibration, earthquakes of, 104. 
 
 Vogt, Carl, on Archeeopteryx, 261. 
 
 Volcanic eruptions of far west, 269. 
 
 Volcanoes, 85 seq., 269; and earth- 
 quakes, 106, 116. 
 
 Wa h sate h, 266, 267. 
 Warm springs, 81, 83 seq. 
 Wastage of the land, 53, 54, 271. 
 Wasted continental surface, 271. 
 Water- basins in the earth, 31. 
 Water, first condensation of, 222. 
 Waverly Sandstone, 242. 
 Waves of earthquakes, 103. 
 Wells and springs, 31, 32. 
 Widder, fossils at, 182. 
 Will, the only source of energy, 309. 
 Winchell, N. H., on Falls of St An- 
 thony, 292. 
 
 World, has been built, 12. 
 World-stuff, 208. See " Cosmic dust. " 
 Wrinkling of strata, 116, 227, 246. 
 
 Yakutsk, frozen soil at, 99. 
 Yellowstone Lake, 80. 
 
 Zeuglodon. 165. 
 
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