1006 Wisconsin Academy of Sciences, Arts, and Letters. 
by Wedderburn (’07), who printed all of the observations and 
also (pp. 420-427) repeated the theory in more detail. The 
next year Wedderburn (’08) recapitulated the theory and says 
that after the epilimnion has been established the variations of 
temperature in the lower water are “principally due to the 
temperature seiche.” Our ideas regarding the change of tem¬ 
perature in the hypolimnion will be greatly changed—or rather 
revolutionized—by this theory, if it is correct. An examina¬ 
tion of the evidence for it is, therefore, not out of place. 
Wedderburn’s paper of 1907 is by far the most complete 
one on this subject and my remarks are based mainly upon it. 
It does not appear that the observations of 1903, which were 
employed by Watson, can be profitably discussed in detail, 
since they were taken at intervals of about twelve hours—morn¬ 
ing and afternoon—and so give no detailed picture of the 
movements of the water or of the wind. Wedderburn, how¬ 
ever, gives an admirable series of temperatures, taken in Loch 
Ness in 1904, chiefly from a yacht anchored near Fort Augus¬ 
tus at the southwest end of the lake. Besides very numerous 
series of temperatures, taken at less frequent intervals, observa¬ 
tions were made every two hours, day and night, from Aug. 
1 to Aug. 24. I do not know any similarly complete series of 
lake temperatures from any other source. It is from this 
series that Wedderburn draws his chief illustrations of seiches, 
and to this I shall refer. 
In discussing the question of temperature seiches it should 
be said that no one doubts the presence of oscillations “in the 
lower layer independent of movements progressing in the up¬ 
per layer” (Wedderburn, ’07, p. 422), or of temperature chan¬ 
ges resulting from them. These have been frequently observed; 
they are always going on and are very numerous and complex. 
The undecided questions are (1) whether there are present in 
the hypolimnion stationary waves, series of pendular move¬ 
ments of the whole mass of this water, and (2), if so, what 
are the extent and importance of such movements. It is plain 
that there is no general or a priori reason why such temperature 
seiches should not exist; on the contrary, they might be ex¬ 
pected to be present. The action of the wind, depressing the 
