Lake Currents.

Lake Currents.

PART II.

A remarkable illustration of the action of lake currents was observed by the writer some forty years ago, on the south shore of Drummond Island in Lake Huron. This island is situated on the east side of the mouth of the St. Mary’s River. A deep bay penetrates the southwest section of the island, and upon the west side of this bay, Fort Drummond was formerly situated. On the east shore of the bay, is a small cape of land, in the interior of which is a pond of about eighty acres in extent. At the time mentioned, the timbers of an old flume svere still in place, which connected the water of the pond with the water in Lake Huron. The set of the current through the flume was very strong, first inwards for a period of from ten to fifteen minutes, then for a similar period it flowed as rapidly in the opposite direction. It is probably that the oscillatory movement of the current was due to changes in atmospheric pressure, the movement being quite active during a prolonged term of calm weather. The flume was about eight (8) feet wide, and when the current was at full ebb, it required the force of several men to push a large row-boat against it into the pond, Littoral currents which are due to the translation of water impelled upon the shores of a lake, by the breaking of waves, are active in proportion to the length of the reach of deep water across which the waves have passed, and to the force and duration of the storms which have generated them, and while in operation, they often effect marked changes in a line of shore which is comprised of moveable material; the greatest effect being produced by a sea running in an angular direction to the trend of the shore upon which the wave force is broken. These littoral currents fluctuate with the changes in direction of the wind.