and other places, yet there not being boats enought to afford help to all, its to be feared many will be lost for want of it. At Oter dam, near Delfziel, but twenty-five persons have escaped; in the village of Peterborne there are but three houses left standing, and in general, all the houses that stood near the dyke have been swept away."

Instances of this kind might be selected to infinity: but we shall confine ourselves to the following extraordinary agitation of the waters of Loch Tay, given in a letter from the Reverend Thomas Fleming to the Reverend John Playfair, M. A.*

"I did not return from the excursion on which I was when I had the pleasure to see you at Dundee till last Tuesday night. On my arrival, I found your letter respecting the phænomenon that lately happened in this neighbourhood. Although ill qualified to give you satisfaction upon this subject, I shall, however, comply with your desire, and give you the most accurate account of that phænomenon which I have been able to obtain.

On Sunday the 12th of September, 1784, about nine o'clock in the morning, an unusual agitation was observed in Loch Tay, near the village of Kenmore. That village stands at the east end of the lake, having the river, which there issues from the lake, on the north side, and a bay, about 160 yards in length and 200 yards in breadth, on the south. The greater part of this bay is very shallow, being generally no more than than two or three feet deep; but before it joins the body of the lake, it becomes suddenly very deep. At the extremity of this bay, the water was observed to retire about five yards within its ordinary boundary, and in four or five minutes to flow out again. In this manner, it ebbed and flowed successively three or four times during the space of a quarter of an hour, when, all at once, the water rushed from the east and west, in opposite currents, towards a line across the bay, and about the edge of the deep, rose in the form of a great wave, to the height of five feet above the ordinary level, leaving the bottom of the bay dry, to the distance of between 90 and 100 yards from its natural boundary. When the opposite currents met, they made a clashing noise, and foamed; and the stronger impulse being from the east, the wave,

* See Transactions of the Royal Society of Edinburgh, Vol I. p. 200.

after rising to its greatest height, rolled westward, but slowly, dimi 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 mauner for the space of two hours, the ebbings succeeding each other at the distance of about seven minutes, 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 I.

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 commron body, aud 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 than that of a few miles on an average. The larger portions of the land we denominate continents; and, in like manner 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 sea's 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