this all. At Vigia, immediately opposite to Souré, on the continental side of the Pará River, just where it meets the sea, we have the counterpart of this submerged forest. Another peat-bog,

with the stumps of innumerable trees standing in it, and encroached upon in the same way by tidal sand, is exposed here also. No doubt these forests were once all continuous, and stretched across the whole basin of what is now called the Pará River.

Since I have been pursuing this inquiry, I have gathered much information to the same effect from persons living on the coast. It is well remembered that, twenty years ago, there existed an island, more than a mile in width, to the northeast of the entrance of the Bay of Vigia, which has now entirely disappeared. Farther eastward, the Bay of Braganza has doubled its width in the last twenty years, and on the shore, within the bay, the sea has gained upon the land for a distance of two hundred yards during a period of only ten years. The latter fact is ascertained by the position of some houses, which were two hundred yards farther from the sea ten years ago than they now are. From these and the like reports, from my own observations on this part of the Brazilian coast, from some investigations made by Major Coutinho at the mouth of the Amazons, on its northern continental shore, near Macapa, and from the reports of Mr. St. John respecting the formations in the valley of the Paranahyba, it is my belief that the changes I have been describing are but a small part of the destruction wrought by the sea on the northeastern shore of this continent. I think it will be found, when the coast has been fully surveyed, that a strip of land not less than a hundred leagues in width, stretching from Cape St. Roque to the northern extremity of South America, has been eaten away by the ocean. If this be so, the Paranahyba and the rivers to the northwest of it, in the province of Maranham, were formerly tributaries of the Amazons; and all that we know thus far of

their geological character goes to prove that this was actually the case. Such an extensive oceanic denudation must have carried away not only the gigantic glacial moraine here assumed to have closed the mouth of the Amazonian basin, but the very ground on which it stood.

During the last four or five years I have been engaged in a series of investigations, in the United States, upon the subject of the denudations connected with the close of the glacial period there, and the encroachments of the ocean upon the drift deposits along the Atlantic coast. Had these investigations been published in detail, with the necessary maps, it would have been far easier for me to explain the facts I have lately observed in the Amazonian Valley, to connect them with facts of a like character on the continent of North America, and to show how remarkably they correspond with facts accomplished during the same period in other parts of the world. While the glacial epoch itself has been very extensively studied in the last half-century, little attention has been paid to the results connected with the breaking up of the geological winter and the final disappearance of the ice. I believe that the true explanation of the presence of a large part of the superficial deposits lately ascribed to the agency of the sea, during temporary subsidences of the land, will be found in the melting of the ice- fields. To this cause I would refer all those deposits which I have designated in former publications as remodelled drift. When the sheet of ice, extending from the Arctic regions over a great part of North America and coming down to the sea, slowly melted away, the waters were not distributed over the face of the country as they now are. They rested upon the bottom deposits of the ice-fields, upon the glacial paste, consisting of clay, sand, pebbles, boulders, etc., underlying the ice. This bottom deposit did not, of course, present an even surface, but must have had extensive undulations and depressions. After

the waters had been drained off from the more elevated ridges, these depressions would still remain full. In the lakes and pools thus formed, stratified deposits would be accumulated, consisting of the most minutely comminuted clay, deposited in thin laminated layers, or sometimes in considerable masses, without any sign of stratification; such differences in the formation being determined by the state of the water, whether perfectly stagnant or more or less agitated. Of such pool deposits overlying the drift there are many instances in the Northern United States. By the overflowing of some of these lakes, and by the emptying of the higher ones into those on a lower level, channels would gradually be formed between the depressions. So began to be marked out our independent river - systems, the waters always seeking their natural level, gradually widening and deepening the channels in which they flowed, as they worked their way down to the sea. When they reached the shore, there followed that antagonism between the rush of the rivers and the action of the tides,-between continental outflows and oceanic encroachments, — which still goes on, and has led to the formation of our eastern rivers, with their wide, open estuaries, such as the James, the Potomac, and the Delaware. All these estuaries are embanked by drift, as are also, in their lower course, the rivers connected with them. Where the country was low and flat, and the drift extended far into the ocean, the encroachment of the sea gave rise, not only to our large estuaries, but also to the sounds and deep bays forming the most prominent indentations of the continental coast, such as the Bay of Fundy, Massachusetts Bay, Long Island Sound, and others. The unmistakable traces of glacial action upon all the islands along the coast of New England, sometimes lying at a very considerable distance from the mainland, give an approximate, though a minimum, measure of the former extent of the glacial drift seaward, and the subse

quent advance of the ocean upon the land. Like those of the harbor of Pará, all these islands have the same geological structure as the continent, and were evidently continuous with it at some former period. All the rocky islands along the coast of Maine and Massachusetts exhibit the glacial traces wherever their surfaces are exposed by the washing away of the drift; and where the drift remains, its character shows that it was once continuous from one island to another, and from all the islands to the mainland.

It is difficult to determine with precision the ancient limit of the glacial drift, but I think it can be shown that it connected the shoals of Newfoundland with the continent; that Nantucket, Martha's Vineyard, and Long Island made part of the mainland; that, in like manner, Nova Scotia, including Sable Island, was united to the southern shore of New Brunswick and Maine, and that the same sheet of drift extended thence to Cape Cod, and stretched southward as far as Cape Hatteras; in short, that the line of shallow soundings along the whole coast of the United States marks the former extent of glacial drift. The ocean has gradually eaten its way into this deposit, and given its present outlines to the continent. These denudations of the sea no doubt began as soon as the breaking up of the ice exposed the drift to its invasion; in other words, at a time when colossal glaciers still poured forth their load of ice into the Atlantic, and fleets of icebergs, far larger and more numerous than those now floated off from the Arctic seas, were launched from the northeastern shore of the United States. Many such masses must have stranded along the shore, and have left various signs of their presence. In fact, the glacial phenomena of the United States and elsewhere are due to two distinct periods: the first of. these was the glacial epoch proper, when the ice was a solid sheet; while to the second belongs the breaking up of this epoch, with the gradual disintegration and dispersion of the ice. We

talk of the theory of glaciers and the theory of icebergs in reference to these phenomena, as if they were exclusively due to one or the other, and whoever accepted the former must reject the latter, and vice versa. When geologists have combined these now discordant elements, and consider these two periods as consecutive, part of the phenomena being due to the glaciers, part to the icebergs and to freshets consequent on their breaking up,-they will find they have covered the whole ground, and that the two theories are perfectly consistent with each other. I think the present disputes upon this subject will end somewhat like those which divided the Neptunic and Plutonic schools of geologists in the early part of this century; the former of whom would have it that all the rocks were due to the action of water, the latter that they were wholly due to the action of fire. The problem was solved, and harmony restored, when it was found that both elements had been equally at work in forming the solid crust of the globe. To the stranded icebergs alluded to above, I have no doubt, is to be referred the origin of the many lakes without outlet existing all over the sandy tract along our coast of which Cape Cod forms a part. Not only the formation of these lakes, but also that of our salt marshes and cranberry-fields, I believe to be connected with the waning of the ice period.

I hope at some future time to publish in detail, with the appropriate maps

and illustrations, my observations on our coast changes, and upon other phenomena connected with the close of the glacial epoch in the United States. It is reversing the natural order of things to give results without the investigations which have led to them; and I should not have introduced the subject here except to show that the fresh-water denudations and the oceanic encroachments which have formed the Amazonian Valley, with its river system, are not isolated facts, but that the process has been the same in both continents. The extraordinary continuity and uniformity of the Amazonian deposits are due to the immense size of the basin enclosed, and the identity of the materials contained in it.

A glance at any geological map of the world will show the reader that the Valley of the Amazons, so far as any attempt is made to explain its structure, is represented as containing isolated tracts of Devonian, Triassic, Jurassic, cretaceous, tertiary, and alluvial deposits. As is shown by the above sketch, this is wholly inaccurate; and whatever may be thought of my interpretation of the actual phenomena, I trust that, in presenting for the first time the formations of the Amazonian basin in their natural connection and sequence, as consisting of three uniform sets of comparatively recent deposits, extending throughout the whole valley, the investigations here recorded have contributed something to the results of modern geology.

I

AM a maniac. I have for some years been the victim of a peculiar insanity, which has greatly distressed several of my friends and relatives. They generally soften it in their talk by the name monomania; but they do not hesitate to aver, when speaking their minds, that it has in truth infected my whole soul, and made me incapable of doing or thinking anything useful or rational. This sad delusion, which they endeavor to remove by serious advice, by playful banter, or by seeming to take an interest in my folly for a moment, is encountered with great acrimony by less gentle friends. They who are not bound to me by blood or intimacy - and some who are - deride, insult, and revile me in every way for my subjection to a mental aberration which is rapidly consuming a pretty property, more than average talents, and unrivalled opportunities.

Of course, like all madmen, I think just the reverse. When the fit is on me, I assert that this fever this madness far from being the bane of my life, is a blessing to it; that I am habitually devoting money, time, and wits to an object at once beautiful and elevating; that I have found consolation in its visions for many sufferings, which all the amusements offered me by my revilers are utterly inadequate to touch. I declare that I have found a better investment for my money than all the West Virginia coal companies that ever sunk oil-wells, and am making more useful acquaintances than if I danced every German during the season. I have not been shut up yet, for my friends know that, if they attempt any such thing, the Finance Committee on the Harvard Memorial and Alumni Hall are in possession of a bond conveying all my money to them; so I am still at large, scolded by my brother Henry, laughed at by my sister Bathsheba, the aversion of Beacon Street, and the scorn of Winthrop Square.

The other day, I took a little journey to Europe, with the view of feeding my madness on that whereby it grows. My friends did not choose to stop me, for they thought the charms of foreign travel might win me from my waywardness. To be sure, when they found, on my return, that I had never left England, they were convinced, if never before, that I was hopelessly insane; for what American, they very sanely said, “would stay in that dull, dingy island, among those stupid, cowardly bullies, when he might live in that lovely Paris, the most interesting and amusing city in the world, unless he were incomprehensibly mad." And, in truth, I begin to think I must be mad, when I find myself, like the man shut up with eleven obstinate jurymen, alone in thinking England a gay, beautiful, happy country, teeming with every gratification of art or nature, and inhabited by a manly, generous, and intelligent race; and that life in Paris, as Americans live it, is a senseless rush after excitement, where comfort is abandoned for unreal luxury, and society for vicious boon-companionship. Still I am very willing to admit that my special mania can be very capitally gratified in Paris, and I am meditating a little trip there for the purpose.

On my return from England, I was observed to be in great distress about a certain box that I missed at Liverpool, looked for at Halifax, and all but lost at East Boston; and when it was found and opened, it only contained two suits of clothes, when, as Henry said, "I might have brought forty, the only thing they did have decent in England,” and all the rest-mad, mad! I beg the readers of the Atlantic to listen to my humble confession of madness, as it culminated in this box.

It is this. The most valuable property a man can possibly have is books; if he has a hundred or a thousand dollars to spare, he had better at once put

--

it into books than into any "paying investments," or any horses, clothes, pictures, or opera-tickets. A life passed among books, thinking, talking, living only for books, is the most amusing and improving life; and to make this possible, the acquisition of a library should be the first object of any one who makes any claim to the possession of luxuries. (My madness only allows me to make one exception, I do acknowledge the solemn duty of laying in a stock of old Madeira.) But so far I have many fellow-maniacs. The special reason why I ought always to stop the Lowell cars at Somerville is, that I consider the reading of books only half the battle. I must have them in choice bindings, in rare imprints, in original editions, and in the most select forms. I must have several copies of a book I have read forty times, as long as there is anything about each copy that makes it peculiar, sui generis. I must own the first edition of Paradise Lost, because it is the first, and in ten books; the second, because it is the first in twelve; then Newton's, then Todd's, then Mitford's, and so on, till my catalogue of Miltons gets to equal Jeames de la Pluche's portraits of the "Dook." "And when," as Henry indignantly says, "he could read Milton all he wanted to, more than I should ever want to, notes and all, in Little and Brown's edition that father gave him, he must go spending money on a parcel of old truck printed a thousand years ago." Mad, quite mad.

Now, to finish the melancholy picture, I am classic mad. I prefer the ancient authors, decidedly, to the moderns. I love them as I never can the moderns; they are my most intimate friends, my heart's own darlings. And how I love to lavish money on them, to see them adorned in every way! How I love to heap them up, Aldines, and Elzevirs, and Baskervilles, and Biponts, in all their grace and majesty. This was what filled that London box. This was all I had to show for twentyfive or thirty guineas of good money; a parcel of trumpery old Greek and

Latin books I had by dozens already! Mad, mad.

Will you come in and see them, ladies and gentlemen? Here they are, all ranged out on my table, large and small, clean and dirty. What have we first?

A goodly fat quarto in white vellum, "Plinii Panegyricus, cum notis Schwarzii, Norimbergæ, 1733." A fine, clean, fresh copy, one of those brave old Teutonic classics of the last century, less exquisitely printed than the Elzevirs, less learnedly critical than the later Germans, but perfectly trustworthy and satisfactory, and attracting every one's eye on a library shelf, by the rich sturdiness of their creamy binding, that smacks of the true Dutch and German burgher wealth. The model of them all is Oudendorp's Cæsar. But there is nothing very great about Pliny's Panegyric, and a man must be a very queer bibliomaniac who would buy up all the vellum classics of the last century he saw. Look inside the cover; read under the book-plate the engraved name, "Edward Gibbon, Esq." What will you, my sanest friend, not give for a book that belonged to the author of the "Decline and Fall"?

The next is also a large quarto, but of a very different character. It is the Baskerville impression of the elegiac poets, — Catullus, Tibullus, and Propertius: Birmingham, 1772. No books are more delightful to sight and touch than the Baskerville classics. This Catullus of mine is printed on the softest and glossiest post paper, with a mighty margin of two inches and a half at the side, and rich broad letters,

the standard n is a tenth of an inch wide, — of a glorious blackness in spite of their ninety-two years of age. The classics of all languages have never been more fitly printed than by Baskerville; and the present book may serve as an admirable lesson to those who think a large-paper book means an ordinary octavo page printed in the middle of a quarto leaf, for instance, Irving's Washington. My Catullus is