after rising to its greatest height, rolled westward, but slowly, dimis nishing as it went, for the space of five minutes, when it wholly disappeared. As the wave subsided, the water flowed back with some force, and exceeded its original boundary four or five yards; then it ebbed again about ten yards, and again returned, and continued to ebb and flow in this manner for the space of two hours, the ebbings succeeding each other at the distance of about seven mi. nutes, and gradually lessening till the water settled into its ordinary level.

At the same time that the undulation was observed in the bay on the south side of the village, the river on the north was seen to run back; the weeds at its bottom, which before pointed with the stream, received a contrary direction; and its channel was left dry above twelve feet from either edge. Under the bridge, (which is sixty or seventy yards from the lake), the current failed, and the bed of the river appeared where there had been eighteen inches of water.

During the whole time that this phænomenon was observed, the weather was calm. It could barely be perceived that the direction of the clouds was from N. E. The barometer (as far as I can re collect) stood the whole of that and the preceding day about 29 inches.

On the next, and the four succeeding days, an ebbing and flowing was observed nearly about the same time, and for the same length of time, but not at all in the same degree as on the first day. A similar agitation was remarked at intervals, some days in the morning, other days in the afternoon, till the 15th of October, since which time no such thing has been observed.

I have not heard (although I have made particular enquiry) that any motion of the earth was felt in this neighbourhood, or that the agitation of the water was observed any where but about the village of Kenmore.

The village of Kenmore is situated nearly in the parallel of 56° 35', and about 1° west of the meridian of Edinburgh. Loch Tay extends from hence somewhat more than 15 miles W. S. W. Its medium breadth is not much less than a mile, and its depth must be very considerable, if one may judge from the height of the adjacent mountains.

EDITOR.

CHAP. XXXII.

THE OCEAN, ITS PROPERTIES AND DIVISIONS.

SECTION J.

1. Introductory Remarks.

DURING the progress of the earth, under the control of the

Almighty fiat, from a state of chaos to a state of order, the laws of gravity seem uniformly to have maintained their power. And hence the immense mass of water which at first lay heterogeneously intermixed with the other principles of things, was gradually pressed out from the rest, ascended to the surface, as the lightest material of the whole, united its particles into one common body, and at length entered in an aggregate form into those immense hollows which were best fitted for its reception. It is these hollows which constitute the bed of the ocean. Hence the natural division of the surface of the globe is into sea and land; about three-fourths of the whole being occupied by water, though probably no where to a depth comparatively very considerable; at most not more thau that of a few miles on an average. The larger portions of the land we denominate continents; and, in like manuer we call the larger divisions of the ocean seas; the distinctive character of the water as compared with that of lakes and rivers, being its saltness, from its holding in solution a considerable quantity of muriat of soda, the source of which we shall presently enquire into. The larger seas are themselves, however, not unfrequently dignified, but improperly, with the name of oceans. Thus that vast expanse

of water which lies to the westward of the northern and southern continents of America, is, on account of the uniform and tempe. rate gales which sweep its surface within the tropics, denominated "the Pacific Ocean;" which has again been distinguished into the Northern and Southern Pacific, the equator being considered as the boundary of each, and the Southern Ocean," being consequently that part of the general assemblage of waters which rolls in the direction from about the fortieth degree of latitude to

ward the south pole. So likewise we speak of the Indian Ocean as extending from the eastern shores of Africa along the southern coasts of Asia; and the Atlantic Ocean as dividing Europe and Africa from the two American continents, while the waters which occupy the polar regions are called the Northern Sea.

Among the chief of those less expansive sheets of water, or those properly called seas, we may mention the Baltic, the Mediterra nean Sea, the Black and the Red Seas: the Caspian Sea, being entirely encompassed by land, might properly be styled a lake, but as its water possesses the quality of saltness, it is ranked among the seas; yet Lake Superior, in North America, is supposed to be of greater circumference than the Caspian Sea; the one being at least fourteen hundred miles around its shores, and the other not more than twelve hundred.

Of the origin of this division into different seas, and seas of dif· ferent depths, we cannot speak with certainty. It is highly proba. ble that many of the larger excavations and partitions which we meet with now, have existed, without much change in regard to their extent, from the creation: others have undoubtedly been the result of that conflict which is perpetually taking place between the elements of land and water, and which has given rise for the most part to islands, isthmuses and peninsulas: while subterraneous volcanos, and the indefatigable exertions of corals, madrepores, tubifores, and other restless and multitudinous zoophytes, have laid, and are daily laying a foundation for new islands or continents in the middle of the widest and deepest seas; all which will furnish us with an additional source of enquiry, and is indeed well worthy of examination.

There is another peculiar feature which characterises the waters of the ocean, and which ought by no means to be overlooked on the present occasion, and that is its tides and currents, and the causes which have been assigned for them; which will necessarily lead us into an examination of the temperature of the ocean at dif. ferent depths, the influence of the heavenly bodies, and especially of the moon upon its general mass.

The sections that follow under this chapter will be found directed to these subjects, and will close that important and extensive divisions of NATURAL HISTORY, which embraces the superficial phænomena to which we have given the name of the globe.

DITOR.

SECTION II.

Alternate Advances and Recessions of the Sea,

FROM what has been already observed of the earth and the ocean, there can be no doubt that they are both in a state of continual fluctuation. The earth, the common magazine for men, animals and vegetables, is continually furnishing its stores to their support. But the matter which is thus derived from it, is soon restored and laid down again, to be prepared for fresh mutations. The transmigration of souls is no doubt false and whimsical; but nothing can be more certain than the transmigration of bodies: the spoils of the meanest reptile may go to the formation of a prince; and, on the contrary, as the poet has it, the body of Cæsar may be employed in stopping a beer-barrel. From this, and other causes, therefore, the earth is in continual change. Its internal fires, the deviation of its rivers, and the falling of its mountains, are daily altering its surface; and geography can no longer recollect the lakes and the vallies that history once fondly dwelt upon.

It

It

But these changes are nothing to the instability of the ocean, would seem that inquietude was as natural to it as fluidity. is first seen with a constant and equable motion going towards the west; the tides then interrupt this progression, and for a time drive the waters in a contrary direction; besides these agitations, the currents act their part in a smaller sphere, being generally greatest where the other motions of the sea are least, namely, nearest the shore: the winds also contribute their share in this universal fluctuation; so that scarcely any part of the sea is wholly seen to stagnate.

Nil enim quiescit, undis impellitur unda,

Et spiritns et calor toto se corpore mişcent *.

As this great element is thus changed, and continually labouring internally, it may be readily supposed that it produces correspondent changes upon its shores, and those parts of the earth subject to its influence. In fact, it is every day making considerable alterations, either by overflowing its shores in one place, or deserting them in others; by covering over whole tracts of country, that were culti

Nothing is still; o'er surges surges pass;

And heat and action mix through all the mass.

vated and peopled, at one time; or by leaving its bed to be appropriated to the purposes of vegetation, and to supply a new theatre for human industry at another.

In this struggle between the earth and the sea for dominion, the greatest number of our shores seem to defy the whole rage of the waves, both by their height and the rocky materials of which they are composed. The coasts of Italy, for instance, are bordered with rocks of marble of different kinds, the quarries of which may easily be distinguished at a distance from sea, and appear like per. pendicular columns, of the most beautiful kinds of marble, ranged along the shore. In general, the eoasts of France, from Brest to Bourdeaux, are composed of rocks; as are also those of Spain and England, which defend the land, and only are interrupted, here and there, to give an egress to rivers, and to allow the conveni. ences of bays and harbours to our shipping. It may be in general remarked, that wherever the sea is most violent and furious, there the boldest shores, and of the most compact materials, are found to oppose it. There are many shores several hundred feet perpen. dicular, against which the sea, when swollen with tides or storms, rises and beats with inconceivable fury. In the Orkneys, where the shores are thus formed, it sometimes, when agitated by a storm, rises two hundred feet perpendicular, and dashes up its spray, together with sand, and other substances that compose its bottom, upon land, like showers of rain.

Hence, therefore, we may conceive how the violence of the sea, and the boldness of the shore, may be said to have made each other. Where the sea meets no obstacles, if spreads its waters with a gen. tle intumescence, till all its power is destroyed, by wanting depth to aid the motion. But when its progress is checked in the midst, by the prominence of rocks, or the abrupt elevation of the land, it dashes with all the force of its depth against the obstacle, and forms by its repeated violence, that abruptness of the shore which confines its impetuosity. Where the sea is extremely deep, or very much vexed by tempests, it is no small obstacle that can confine its rage-and for this reason we see the boldest shores projected against the deepest waters; all less impediments having long before been surmounted and washed away.

In places where the force of the sea is less violent, or its tides less rapid, the shores are generally seen to descend with a more gradual