and periodically subject to droughts, rains, heavy floods, inundations, and denudations. Some of the lagoons become dry, and the thick mud at the bottom, when in a moist state, incloses alligators and other amphibious reptiles during the dry season. They remain entombed like eels, in a somewhat dormant state, and come to life again in the rainy season if the dry lagoons be not in the interim too thickly covered by gravel. In the upper regions during the rainy seasons landslips occur daily, and large masses of forests and trees of colossal dimensions are brought down, and the banks of the rivers and the lower plains become frequently strewed over with the débris. Some of the large marshes and lagoons are often changed in a day into plains of gravel, and the sandy plains are converted into lagoons teeming with life. The delta of the Amazon exposed to these periodical floods comprises an area equal to one-half of England.

I remember a great flood and an avalanche which occurred on February 19th, 1845, on the eastern flank of the central Andes. Immense masses of ice and boulders gave way on the upper part of the Paramo de Ruiz, in latitude 5° north, and came down the ravines in awful torrents of muddy water, with ice, large granitic and porphyritic boulders, broken fern-trees, &c., laying waste many square leagues of the hot plains below. The destruction of human beings, animals and property was immense. Two or three rivers in the plains were choked, and their channels changed; and over many square miles of the fertile plains were deposited several feet of sand and gravel, inclosing trunks of trees belonging to the upper cold regions mixed with those flourishing in the hot countries below. The tobacco, sugar and guinea-grass plantations were completely destroyed, and upwards of 1,000 natives perished by this glacial deluge, or avalanche, in less than twelve hours. The quantity of sand and gravel deposited on that day was estimated at upwards of 250 millions of tons. The ice and boulders brought down from the snowy region to the hot plains below killed a very large quantity of fish and reptiles. The beds of sand and gravel may be still seen occupying a very large area, and in places clothed with rank vegetation, but the catastrophe is almost forgotten amongst the inhabitants. Were an ardent young student of geology, trained in the recently-accepted geological theory, to visit this district now, and examine the formation, he might possibly conclude that it belonged to the glacial period, and was of very remote antiquity. I could mention various and extensive changes which have taken place in the interior and along the coast of South America since the Spanish conquest, but I need not

dwell on them on this occasion. I shall conclude with noticing some of the changes which have been, and still are, going on in Africa and Asia.

M. Charles Martins, of Montpellier, gives the following account of the physical characters of the great Sahara, or desert, in the province of Constantine :

"We entered a district composed of grey, blue, yellow, and red marles, associated with conglomerates and limestones, cut up into deep ravines by the torrents which, during the rainy season, descend from the rock-salt mountains. These ravines, from fifty to sixty yards in depth, were so close to each other that it would have required several days to reach the foot of the mountain, distant only a few miles in a straight line, through this labyrinth of gorges separated by sharp narrow ridges. Let those geologists who wish to describe the erosive action of pluvial waters set aside the wretched examples they quote to illustrate their argument; let them visit Algeria, and gain their inspirations from the ravined district of Djebel-el-Mela and the mountains of the Kabyle. There they will see how the erosive power of water is able, under our very eyes, to transform a level plain into a mass of mountains as varied and broken in their forms as those which have been caused by the elevation and fracture of strata.”"

The Sahara itself is a dried-up sea-bottom. No correct estimate can be made when the inland sea disappeared, but the indications presented by the marine deposits favour the idea that the event was not very remote. M. Martins observes :"When it took place, the Mediterranean existed as it is now, for we find in the Sahara the shells of the same mollusca which still live on its shores." Indeed, a very large area of the Sahara is still below the level of the Mediterranean Sea, from which it is separated by an isthmus of sand and gravel. The communication having been thus closed, the inland sea-waters have been absorbed and evaporated. "Were this isthmus broken through, a large area of the Sahara would again become a sea." These changes bordering the African coast appear to have been brought about more from the influence of prevalent winds and currents, tropical rains, and the sandstorms of the desert, than from any great upheavals. Drifted sands in eastern Africa have overwhelmed the temple of Jupiter Ammon and the villages on the west side of the Nile, and have thus converted the scenes of habitation and cultivation into a barren, sandy desert during the last three thousand years. Look at Thebes and behold its colossal columns, statues, temples, obelisks, all desolated and dilapidated. Yet its hundred gates were celebrated by Homer, and its magnificence praised during its decline even by the Romans. It and other great cities, including Carthage, flourished within the last

3,000 years. The drifting of the sands of the Nubian desert produces remarkable changes in a comparatively short time. The encroachment of the Nubian sandy desert is irresistible, and the population is gradually emigrating to Lower Egypt. Where the land has been abandoned, the advance of the sand on the cultivated districts is becoming more apparent. About sixty-five miles north of Wadi Halfeh the desert has covered a great alluvial plain, which had formerly been under cultivation, and is approaching the river, so that the trunks of the palmtrees are completely surrounded with sand for upwards of fifteen feet from their roots. Although rain seldom falls in Nubia, yet, when such is the case, the fall is remarkable for its violence, as testified by the magnitude of the water-courses and the heaps of boulders, gravel, and sands. I could mention numbers of other changes which have been brought about during a few centuries, of the same character as those which geologists have ascribed to many thousands of years. Even the cities of Pompeii and Herculaneum, which have been discovered entombed in the vicinity of Vesuvius, were all but lost to history. Had it not been for Dion Cassius incidentally noticing their destruction, about a century and a half after the catastrophe (which occurred about 1,785 years ago), their ages would, doubtless, have been computed as of many thousands of years. If, then, these changes have been so much overlooked in the centre of the civilized world, we cannot expect to obtain complete accounts in other and less favoured regions.

Had it not been for the records of Holy Writ and of profane history, the relics found in the mounds of Nineveh would, doubtless, have been assigned to countless ages past, like the mounds in the basin of the Mississippi, which have been computed as 50,000 years old. Two thousand five hundred years ago Nineveh flourished in all its grandeur. Never did any city equal it in greatness and magnificence, yet it is now buried in oblivion, and its site overwhelmed with sand. Where is Babylon, the glory of kingdoms? The very ground on which it stood is a scene of desolation-drifted sands and pools of water. Yet this great capital of the Chaldeans was in all its splendour as late as about 2,200 years ago.

The scenes of our terrestrial habitation are not permanent, but ever changing. I have appealed to demonstrable facts; but the alleged myriads of years required to effect such changes are purely imaginary, totally unworthy of those who seek the fundamental facts of science; and they ought not to be used as the foundation of arguments against the veracity of the Mosaic record. It is my firm persuasion that the more closely we study the actual conditions of the earth and its true geo

logical changes, setting aside all rash speculations, the stronger will become our convictions of the substantial truth and marvellous accuracy of the Holy Scriptures, in the account of the Creation in Genesis, and in other allusions to the facts of nature throughout the sacred text.

The CHAIRMAN.—I need scarcely call upon you to return thanks for this valuable paper, the more valuable as it is bristling with facts, gathered from a very extensive survey of the globe. It is not a paper made up from researches in geological works. It bears the impress of actual investigation, and of such investigation as few men have opportunities of making. I cannot but conceive that the vast mass of facts brought before us must be of very great value in the records of this Institute, and that they will be quoted from those records by many with great satisfaction.

see.

Professor OLIVER BYRNE.-I have been viewing this subject from a different stand-point to that of Mr. Evan Hopkins; but I think that the conclusions and calculations I have come to will establish without much doubt the truth of his observations, carried further down than he was able to Astronomers say that this earth has six motions—the annual, diurnal, precession of the equinoxes, solar nutation, lunar nutation (established by theory and not by observation), and the collapsing of the planes of the equator and ecliptic. I say there are only three-the annual, diurnal, and the right motion of the earth's axis. I have travelled over the whole country Mr. Evan Hopkins has surveyed; I have been in South America and up the Nile, and had an opportunity of seeing that he is perfectly correct in his statements, as far as I could investigate. But the mathematical reason of all this is simple indeed. The earth being an oblate spheroid, revolving on its axis, has a protuberance at the equator, making the diameter there twenty-six miles greater than the diameter through the poles. If this earth was a perfect globe, the action of the sun and moon upon it—as a perfect globe-would have no influence to change the spinning position of the body. It is not a change of the whole body, axis and all, but a swinging of the body upon a consecutive axis, that changes the latitude of any place. There are twenty-six miles of a bulb always changing their position; and the action of all the particles must be perpendicular to tangent planes and in the direction of the plumb-line, from this combined motion. The fact is, that sand being loose, it nearly obeys the same laws of motion as a fluid like water; but the hard rock of the earth changes altogether and all at once. This pro tuberance progresses continually round the earth; and twenty-six miles of a mountain moving on consecutively, causes all these changes. And that this motion of the earth is in existence can be proved as easily as anything in the multiplication table. Then if we take and examine the changes that have taken place in sun-dials-the one dug up in Herculaneum for instance, we find that the position of the dial at the time it was in use, would not tell the time correctly now. Take another instance--the city of Philadelphia, in our own time :--Market Street and Broad Street

cross at right angles, and the instrument with which Philadelphia was laid out is still in existence; yet the whole city of Philadelphia has moved in accordance with this law. The bases of all churches, laid out east, west, north, and south, have changed. There is not a single observatory in the world in which an astronomer has taken his latitude where such astronomer does not differ from his predecessor; and that this does not arise from errors is proved, because the difference is always in one way. It is very extraordinary that all the "errors" run one way, and in every place, according to this law. In our own country, on the plains of Norbury, in Wiltshire, the Druids erected their stones in an ellipse, to receive the rays of the sun at the period of the summer solstice; but it is now 123 degrees from that position. You can get any number of facts to prove the soundness of Mr. Evan Hopkins's views, that the rocks are perpendicular, and that changes of position take place; and that not so much time as millions of years is required, as some suppose. It would not take 500 years, under certain circumstances, to change the whole country altogether, or even to raise the whole of the bed of the Pacific Ocean. Geologists tell me that insects are there building upwards from the bottom at the rate of 4 inches a year. Fancy insects doing this over the entire bed of the Pacific! No. It is the foundation rising. We are gradually going out of our present latitude; and so our climates change, and everything else changes in accordance.

Captain FISHBOURNE.-I may mention a fact which is rather relevant to this discussion. When, in the reign of the Empress Catherine, the city of Krasnajask was discovered in Siberia (it is some twenty-five years since I read the narrative, but to the best of my recollection that was the name), M. Pallas, a Frenchman, was sent to report upon the discovery; and he found amongst other things sun-dials, but the gnomons were not set at an angle to suit the latitude. His explanation was that these sun-dials had been imported from a previous centre of civilization, and that the people were ignorant of their inaccuracy. But that, of course, is not likely; for if they used them they would have found that they would not give time correctly. This would quite agree with the supposition of Mr. Byrne, that the situation itself had altered in latitude; and so that the sun-dials found there were suitable to the place-to the city of Krasnajask, when it was in its original position, and when founded.

Mr. REDDIE. As bearing upon some of the views put forward in the paper read by Mr. Hopkins, I will quote a paragraph which I observed in the Dublin Daily Express of the 20th of November. It states, that at a meeting of the Royal Dublin Society,

"Mr. Robert H. Scott read his translation of a paper by Professor Oswald Heer, of Zurich, 'On the Miocene Flora of Atane-kerdluk and North Greenland. The paper was interesting both from a botanical and geological point of view, and it went to prove from fossil specimens of forest trees at Atane-kerdluk, in North Greenland, especially the Sequoia sempervirens (red-wood), that the climate of Greenland had formerly been thirty degrees higher than at present; the ordinary temperature of the locality being now twenty-one degrees, while the most northern latitude in which that plant