1895-96.] RAINFALL AND LAKE LEVELS. 127 



and 1893. At the beginning of this same period in 1887 Lake Ontario 

 was high, but two years of exceedingly small rainfall rapidly lowered the 

 level. In 1889 and 1890 the rainfall was above average and temporarily 

 checked the fall which would have resulted from the low water in the 

 Upper Lakes, but in 1891 a marked deficiency of precipitation brought 

 a very low winter stage. Two years, 1892 and 1893, of above average 

 rainfall now improved the level a little, but the deficiency of rainfall in 

 1894 and 1895, and particularly in the latter year, in conjunction with 

 the effect of a small intake of water by the Niagara River, doubtless 

 produced the almost phenomenally low stage of the past year. I believe 

 that these facts are amply sufficient to explain the present state of affairs. 



I was at first rather nonplussed to account for the fact that the 

 highest water on record, in 1838, occurred during a period which the 

 Ohio and New York records which I have quoted, indicate as a dry 

 period, but I now think that it is probably quite unnecessary to be dis- 

 concerted by this, as our table giving departures from average rainfall 

 during the various years in the several drainage areas, shews so conclu- 

 sively that when the Ontario district has an under average rainfall the 

 Upper Lakes usually have an excess. We have a very significant 

 instance of the effect of such conditions, when between 1881 and 1884 

 Ontario rose from low water to a decidedly high stage, notwithstanding 

 a marked deficiency of rainfall during the four years. Somewhat similar 

 conditions prior to 1838 may well have produced the very high stage of 

 that year. 



Meteorologists have so far been unable to prove that terms of exces- 

 sive rainfall or the contrary are periodical. It is not, however, improb- 

 able that there are several physical influences which periodically affect 

 the precipitation, and it may be that in some periods these influences 

 work in unison to increase it while at other times they interfere, and 

 should this supposition be correct, we can easily understand that we 

 are dealing with a very complicated subject, and that observations during 

 a long period of years will be necessary to unravel the m)'ster\'. 



In view of these facts it is quite unreasonable to suppose that Lake 

 Ontario will this year or even next year attain a high stage, the increase 

 is likel)' to be gradual. Lake Superior is, as we have seen already, high; 

 this will help to raise the level of Huron, which lake will rise if the rain- 

 fall be even up to average, and then with an improving head of water in 

 that lake, and consequently in Erie, the flow by the Niagara will improve 

 and assist in raising the level of Ontario, but with so many factors to be 

 considered it is impossible to predict with any certainty how long it will 

 be before a really high stage is again reached. 



I. 



