Descriptive Statement of the Great Water Highways of the Dominion of Canada; Hydrology of the Basin of the Gulf and River St. Lawrence

This historic book may have numerous typos and missing text. Purchasers can usually download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1874 edition. Excerpt: ... long pools and ripples, with a current alternately sluggish and rapid, with bars in the upper part of it consisting of gravel, and in the lower part of shifting sand. The rain fall of the Ohio Valley may, perhaps, slightly exceed that over the average of the St. Lawrence Valley, as far as we have the means of calculating (the average fall over its area being, perhaps, fifteen per cent, more than that of the St. Lawrence basin); yet the range between extreme low and extreme high water is about forty-five feet throughout the river. At Wheeling, Virginia, eight hundred and ninety miles above its junction with the Mississippi, it is forty-five feet; at Louisville, forty-two feet on the Falls, and sixty-four feet below them; at Evansville, forty feet; at Paducah, fifty-one feet; and at its confluence with the great Mississippi, fifty-one feet. The usual range does not exceed twenty-five feet. The usual rise in the Ohio takes place in February, and occasionally as late as March. This arises from the melting of the snows, and generally amounting to twenty-five feet; the river remains high for about six weeks. Another rise takes place in May, or June, due to the summer rains, lasting from three to four weeks at Cairo, and from one to two at Louisville. In October the lowest stage is obtained, when it is navigable chiefly for boats of eighteen inches draught; but in November, the river generally begins to rise, and continues to do so until the banks are full. These floods are due to the autumn rains, which are sometimes continued as late as the end of December. FLUCTUATIONS OF LEVEL IN THE ELEVATION OF THE SURFACES IN THE GREAT LAKES. It cannot be surprising that suppositions have been entertained as to the existence of tides upon these large...