No. 392.] AN ABNORMAL WAVE IN LAKE ERIE, 659 
We had a heavy gust of wind striking the lake obliquely as 
a characteristic result of the thunderstorm. All stations at 
the western end of the lake reported a gale from the northwest 
as accompanying the thunderstorm. 
Another of the causes which was present was a storm. 
Whether the storm was the principal cause or not, is difficult 
to say ; although, by agitating parts of the lake and causing an 
unstable equilibrium in the atmosphere, it undoubtedly entered 
in as a cause. 
Theoretically, at least, electrical attraction would have some 
influence upon the action of the water; but owing to our pres- 
ent incomplete knowledge of the subject we do not know how 
great the actual effect would be. 
In the opinion of the writer the oblique blow given to the 
water by the northwest wind, and the agitation of water and 
atmosphere, caused by the storm, were the principal factors 
causifig the result. 
This theory seems to be supported by the account of the 
eyewitness who described the northwest wind following the 
wave. 
There are objections, though, to calling it a seiche. <A true 
seiche is a rhythmic oscillation of the surface of a lake, whereas 
in this case oscillations seem to have been lacking at some 
places. 
One of the most puzzling circumstances in connection with 
this phenomenon is the fact that where the wave seems to 
have struck the shore first, z.e., about five miles west of Erie, 
where the water is shallow for about four miles out, there were 
three waves; while fifteen miles east of Erie, where the water 
is deeper, there was but one wave. In investigating the cause 
for this change in the make-up of the wave we should en- 
counter much theory and speculation, which would not be 
entirely reliable unless we knew all the attending conditions. 
But we can say one thing with some degree of certainty, vez. : 
if the direction of the waves made an angle of less than 45° 
with the shore line, the first wave striking the shore would be 
reflected at such an angle that it will meet and combine with 
the second wave and form a resultant wave farther along the 
