296 



ON THE PERIODICAL RISE AM> PALL OF THE LAKES. 



[1854 



in every fourteen years, or that its recurrence has been mtffi- 

 cienth precise to authorise the belief in its regularity; but that 

 tin- New if oik Canal Commissioners state the intervals to bo 

 onee in about eleven years; and that no actual observations ap- 

 peared i" have been made on the progrei of the elevation, as 

 in whether there were anj preceding seasons of a character to 

 produce it; and, therefore, nfter noticing various well-known 

 periods at which remarkable elevations and depre i"' 1 -- took 



pli , such as in 1800, 1815, 1820, 1828, and 18:30, by wa] of 



proof of the periodical return of that phen ■ i beingregular 



or otherwise, he was obliged o<> come to the conclusion that, as 

 far as fuels go, they arc certainly in favour of the popular theory, 

 I'ut that it rests on these facts alone, and is in many other points 

 of view improbable and absurd; and that we are therefore con 

 strained to suppose, though destitute of this light of actual ob- 

 servation, that the fluctuations observed must have been caused 

 by unusually abundant rains and snow, and that this abundance 

 had been in fortuitous coincidence with certain cycles of time; 

 for, improbable as this may be, it is less so than that nature 

 should have departed from her ordinary course.* 



Having, in a previous page, quoted largely from Mr. Weld, I 

 now proceed to notice the judicious remarks on the rise and fall 

 of the Lakes by another intelligent British observer, Mr. Mc- 

 Taggart, who, writing in 1828, sets out by at once affirming 

 that "there are no tides in any of the Lakes — none, at least, 

 from the moon's influence: but that the floods of spring gene- 

 rally raise them from three to four feet. It is said that Lake 

 Ontario rises once in every seven years higher than usual by 

 two feet. The people ascribe this to some supernatuial cause. 

 In the spring of 1S27 it had one of these periodical tides, rising 

 nearly three feet higher than it had done the previous year, and 

 keeping high the -whole summer. Being in the neighbourhood 

 (observes Mr. McT.) I paid the utmost attention to the pheno- 

 menon, and found that there fell during that summer much 

 more rain than had fallen for many years before; and that there 

 was little sunshine throughout the season; and I, consequently, 

 concluded that the exhalations from the Lake were not so- copi- 

 ous. There was another circumstance that puzzled me. Lake 

 Ontario, and indeed, all the Lakes were up to their very highest 

 surface marks, but the rivers flowing out of them were not. 

 Those surface marks were very obvious on the rocky shores of 

 the Lakes, drawn like so many chalk lines by Nature herself. 



" Rivers do not rise exactly from the same cause as Lakes. If 

 in spring the snow melts off the country on a sudden, and the 

 frozen swamps break up and disembogue their contents, then the 

 rivers will rise to their utmost height as water pours into them 

 on all sides; but when the sun has effected this, they begin to 

 fall. Lakes swell, it is true, from the same cause, but not with 

 the same comparative haste; their surface being of great extent, 

 the floods can only spread over them by slow degrees ; and if 

 tho sky keep cloudy and the weather moist, so that little evapo- 

 ration goes on, the surface of the Lake will continue to swell, 

 while that of the river will foil — as the country on either side is 

 drained — nothing tending to keep up its flood but the mere dis- 

 charge from the Lake. Rivers and Lakes are never at their ut- 

 most pitch of flood at the same time ; neither are they ever at 

 the lowest ebb at the same time; for when the floods of a river 

 have subsided to a certain extent, the intense heat of the sum- 

 mer sun, setting upon the shelving sides of the rocky channels, 

 and even upon the bed of the river itself, tends greatly to pro- 



* See American Journal of Science, Vol. 20, pp. 218, 219. 



mote the absorption of the waters, whereas in the deep wide 

 Lake this action cannot take place. 



"The unusual rise of the waters of the Lakes in some seasons, 

 which some observers state to be seven feel above the common 

 level, seem tobeonlj ral led for by the absence of 



evaporation, and greater quantities of rain than generally prevail. 



One: in i i| is said to rise thus; but 7, like :), 



is a number open to superstition,! not to be always relied on, 

 and it would not be surprising if this How were to happen once 

 in six, or even in ten years. It will yet, likely, be discovered 



that when Lake Erie has its brim ll I, the others have theirs 



al i during the same season ; and when powerful suns are ex- 

 cluded from drinking them up, by the intervention of drizzling 

 clouds, and this exclusion extending over an immense surface, we 

 shall cease to marvel at these wonderful septennial floods. It 

 has also been remarked that the winters after these seasons have 

 had little snow ; but meteorology on this score remains to be 

 further prosecuted, ere Ike theory dare he advanced, that it is 

 from Ike moisture absorbed in circumjacent regions during sum- 

 mer that the snows of winter are supplied." 



Passing from the borders of Lake Ontario to the regions of 

 Lake Superior, I am next enabled to refer to some equally per- 

 emptory observations on the same subject, made by that eminent 

 British hydrographer and geologist, Oapt. Bayfield, on the spot, 

 in the course of 1825-20; from whose valuable and interesting 

 paper on the geology of the latter Lake I extract the following 

 particulars:! 



"There is no regularly periodical rising or falling of the Lakes, 

 as has been asserted, whether it be from the influence of the 

 moon, or any other. They rise and fall from accidental causes ; 

 such as a very severe winter without the usual thaws. The 

 springs are locked up all winter, and the whole accumulated 

 snow remains until the spring, when the weather, becoming sud- 

 denly warm, dissolves it at once. Hence it will generally be 

 found that after a very severe winter, the waters of the Lakes 

 will be much higher than at other times. Heavy gales also 

 raise the water in the upper parts of the Lakes, and also cause 

 currents in various directions. The rise, however, in Lakes Su- 

 perior and Huron, from this or any other cause, never exceeds a 

 few feet . . Whether a gradual diminution of the waters of 

 Lake Superior is now going on, is a point on which no one is qua- 

 lified to give an opinion ; for no observations have been made or 

 recorded to ascertain the interesting fact. Any diminution must 

 be always imperceptibly gradual, and would require constant, 

 accurate, and regularly recorded observations during a great 

 number of years to render this indisputable. The streams 

 which discharge into Lake Superior amount to several hundreds 

 in number, and the quantity of water supplied by them is many- 

 times greater than that discharged at the falls of St Mary, the 

 only outlet. There is, however, no reason to imagine from this 

 that the quantity of water increases; for it is absolutely neces- 

 sary that there should be a supply very far exceeding the dis- 

 charge, to replace the immense expenditure arising from the eva- 

 poration from so extensive a surface." 



Adhering to my intention of reserving for the present any 

 comments on the above, as of other quotations, I now revert to 



f It was stated by Professor Johnston, in his address at the New York 

 Agricultural Society meeting at Syracuse, as a fact, that Holland is ex] 

 on the average of the last thirteen centuries, to one great sea or river ilood, 

 .every seven years. — R. L. 



$ See Transactions of the Lit. and Hist, of Quebec, Vol. I., pp. 1 to 43. 



