658 THE AMERICAN NATURALIST.  [Vow. XXXIII. 
quake shock had occurred at that hour of the day, it would have 
been noticed at some point on the shore, or by some vessel on 
the lake, which was not the case. Furthermore, an earthquake 
wave of the size noted would not be local, but probably would 
be noticed at many, if not all, points on the lake shore. 
Was it an example of water piled by the wind? 
We can be quite sure that this was not the cause, for on 
the previous evening there was a calm area near the locality 
where the rise occurred, away from which the wind blew in 
three or four different directions. And although, after sunrise 
on the 19th, the wind kept a generally southeast direction, 
with an average velocity of nine miles an hour, we may be 
quite sure that so light a wind, blowing upon a large body of 
water for so short a time, at right angles to its longer axis, 
could not have been the cause of the phenomenon. 
It may be asked if a difference of barometric pressure might 
not account for the difference of level of the water. 
It is very possible that this may be an indirect cause of the 
rise, but it is not competent in itself to produce such a change 
in level. By reference to the barometric conditions for the 
1gth, it will be seen that there was a «“ high” area near the 
central portion of the lake at 8 p.m., where the barometer was 
0.08 to 0.09 inches higher than at either end of the lake. As 
a column of mercury thirty inches high corresponds to a col- 
umn of water thirty-four feet high, the column of water able 
to be supported by the pressure in the “ high ” area would only 
differ about an inch from the column able to be supported by 
the pressure at either end of the lake. So the water in the 
central portion of the lake would only need to fluctuate about 
half an inch in order to establish its equilibrium. 
Was the phenomenon a seiche ? 
Forel gives as causes of seiches: (a) rapid local variation of 
atmospheric pressure ; (4) relaxation of the wind which has 
heaped the lake waters up to one side; (c) a gust of wind 
striking the lake obliquely; (ď) electrical attraction; (e) ava- 
lanche winds; (f) earthquakes ; (g) storms. 
Some of these causes were incontestably present at the-time 
this phenomenon occurred. 
