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e largest port and within the sparope, does not exceer

the measure of the great capitals of Europe, does not exceed 170,000 inhabitants; and within the spacious enclosure of the walls, the largest portion of the seven hills is overspread with vineyards and ruins. Each reign (the exceptions are rare) has been marked by the rapid elevation of a new family, enriched by the childless pontiff, at the expense of the church and country.

The palaces of these fortunate nephews are the most costly monuments of elegance : the perfect arts of architecture, painting, and sculpture, have ministered to their service ; and their galleries and gardens are decorated with the most precious works of antiquity, which taste or vanity has prompted them to collect. The ecclesiastical revenues were more decently employed by the popes themselves in the pomp of the Catholic worship; but it is superfluous to enumerate their pious foundations of altars, chapels, and churches, since these lesser stars are eclipsed by the sun of the Vatican, by the dome of St. Peter, the most glorious structure that ever has been applied to the use of religion.

The fame of Julius the Second, Leo the Tenth, and Sixtus the Fifth, is accompanied by the superior merit of Bramante and Fontana, of Raphael and Michael Angelo; and the same munificence which had been displayed in palaces and temples was directed with equal zeal to revive and emulate the labours of antiquity. Prostrate obelisks were raised from the ground, and erected in the most conspicuous places ; of the eleven aqueducts of the Cæsars and consuls, three were restored ; the artificial rivers were conducted over a long series of old, or of new, arches, to discharge into marble basins a flood of salubrious and refreshing waters ; and the spectator, impatient to ascend the steps of St. Peter's, is detained by a column of Egyptian granite, which rises between two lofty and perpetual fountains, to the height of 120 feet. The map, the description, the monuments, of ancient Rome, have been elucidated by the diligence of the antiquarian and the student; and the foot

steps of heroes, the relics, not of superstition, but of empire, are devoutly visited by a new race of pilgrims, from the remote, and once savage, countries of the North.-GIBBON.

CHAPTER VIII.

GEOLOGICAL HISTORY. THERE are many analogies between geological history and that of any nation. In the history of a people, for instance, it usually happens that most difficulty is found in tracing their beginning, both from the fewness of the documents possessed and the difficulty of their interpretation; the parts into which human history can be divided are also very often separated by mere blank periods of darkness and barbarism, of which no trustworthy records remain to us. In all human histories that which is written is but a brief abstract of that which happened. How much even of what is recorded in our daily papers will appear in history 500 years hence ? the answer will show us how much less we have of the history of 500 years ago, when there were no public journals.

Geological history must needs be far more deficient than that of nations. It has literally no beginning: it commences with a few scattered, half-obliterated documents, that only show us that something happened before, like that which has occurred since. It is separated into parts by great intervals, of which, not only have no records been discovered, but there is no evidence even as to the length of the intervals.

Singularly interesting and useful then as geological history may be, we must carefully bear in mind its imperfect and fragmentary character.

What we actually learn from it is true, but we must recollect that it is not all the truth, and that as "all the truthabout anvthing whatever is absolutely unattainable by

us, it would only lead us astray, if we required it from Geology, or reasoned as if we had obtained it.

It has been found convenient to divide all Geological Time into three great Epochs, called Primary, Secondary, and Tertiary. It is obvious that we may speak of the rocks deposited during these respective Epochs as the Primary, Secondary, and Tertiary rocks. It was at one time thought that there was some original essential distinction in the nature of these rocks and their mode of formation. It is now known that the Primary rocks, when first formed, were exactly like the corresponding Secondary and Tertiary, or like those now forming on the globe, and that any peculiar characters they may have in the way of hardness, slatiness, or crystallisation, are due to subsequent modifying influences.

In order to get rid more completely of the old notions that clung to these terms, geologists have lately been in the habit of using for them those proposed by Professor Phillipsnamely, Palæozoic, Mesozoic, and Kainozoic. Palæozoic meaning "ancient life," answers to the term Primary; Mesozoic or middle life,” to the term Secondary; and Kainozoic or "recent life,to the Tertiary.

Each of these epochs is subdivided into periods, each of which was occupied by the deposition of a certain group or series of stratified rocks.

The whole history is based upon the observation of these groups of beds resting successively one upon another; and the following table will give the names which have been assigned to these groups of rock, or, as it is better to state it, to the periods during which they were deposited.

Tertiary or Kainozoic Epoch.

14. Pleistocene period.
13. Pleiocene period.
12. Meiocene period.
11. Eocene period.

Mesozoic or Secondary Epoch.

10. Cretaceous period.
9. Oolitic period.

8. Triassic period.
Palæozoic or Primary Epoch.

7. Permian period.
6. Carboniferous period.
5. ? Devonian ?* period.
4. Upper Silurian period.
3. Cambro-Silurian period.
2. Cambrian period.

1. Præ-Cambrian periods. On looking over this list of names for the first time, many of them will doubtless seem to be rather odd appellations for periods of time. That circumstance, however, need not trouble us any more than the odd names of persons that occur among ourselves.

Names in general originate as descriptive appellations, and apply peculiarly to the person or thing to which they are first affixed. They are, however, continued or extended to other persons or things related to the first, in some way that makes the retention of the name necessary, although it is no longer applicable as a description and is sometimes ridiculously inappropriate. John Short does not change his name because he is over six feet high, nor Thomas Long if he happens to be five feet nothing.

So, in Geology, if a group of rocks happen to consist of red or green sandstones at the place where they were first examined, and are therefore called The Greensand or The Red Sandstone; and if, as they are followed into another district, they gradually pass into dark clay or white limestone, they sometimes still retain the old name as a group. Thus the Chalk or Cretaceous rocks of Western Europe not only contain variously coloured sands and clays in that region, but in other parts of the world have no chalk in them at all, and consist, in some parts, of sands and clays with beds of bituminous coal, and in other regions of clay-slate. The retention of the name Cretaceous for such groups is necessary, to show that they are contemporaneous with the chalk beds of the locality where that group was first examined.

* The queries appended to this name signify that its propriety is doubt. ful, and that it perhaps originated in a very pardonable mistake.

.. CHAPTER IX.

GEOLOGICAL HISTORY. The amount of any one of the physical operations now taking place in or upon the crust of the globe, which is brought about at any particular place, during the life-time of any one man, may be so small as to be almost imperceptible ; and he may at first, accordingly, think the operation itself hardly worth regarding. This, however, would be a great mistake, We might as reasonably disregard the lapse of time because, at a hasty glance, we could not perceive any motion in the hour hand of a clock, or the shadow of a dial.

The principal bulk of all the dry land on the globe, to a great depth beneath the surface, is formed of rock that has been accumulated, grain by grain, at the bottom of the sea. This is true also for much of the rock that lies beneath the sea itself, perhaps for almost all of it. This grain by grain accumulation has taken place, not everywhere at once, but piecemeal and in patches, here and there about the globe, just as our present seas and lakes are now receiving small and partial beds of sand, or mud, or lime, first in one place and then in another. The dry land which seems so solid and

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