AGITATION of the waters of lakes, &c. a natur,ll phenomenon, which generally accompanies earthquake though agitations have sometimes been perceived when no motion of the earth was felt. A very reinal kable phenomenon of this kind was observed by Dr Fleming, on the morning of the 12th September 1784, in Loch Tay, in the Highlands of Scotland. The water or a hay in this lake was observed to retire above five yards with in its ordinary boundary, and in four or five minutes re sumed its former level. This agitation was repeated three or four times in a quarter of au hour, when all on a sudden, the water rushed from the east and west in opposite currents across the bay ;Itpd near the margin of the deep part of the bay, it rose in the form of a great wave, leaving the bottom of the hay dry, at the distance of about 100 yards from its natural boundary. When the opposing currents met, they made a clashing noise ; and as the strongest impulse was from the cast, the wave rolled slowly westward, gradually diminishing for the space of five minutes, when it wholly disappeared. The
water continued to ebb and flow, in about the space of seven minutes, for two hours, when the agitation ceased. At the same time, a river north of the bay ran back wards, and retired about 12 feet from its opposite banks. For five succeeding days the ebbing and flowing conti nued, and similar agitations were occasionally observed till the 15th of October, since which they have never returned. Dr Fleming's paper will be found in the Transactions of the Royal Society of Edinburgh, vol. i. p. 200. For an account of similar phenomena, see Pl,d. Trans. 1756, p. 521, 523, 530, 54. Id. vol. >Aix. p. 642.
1762, p. 477. Phil. fling. vol. xi. p. 163. (w)