two
secondary maxima of Curve _F_ would be replaced by a single one on
Wednesday or Thursday.

One more question remains for consideration in connection with this weekly
rhythm. Is it possible to trace any connection between the weekly and
yearly rhythms of such a character that the weekly day of maximum
discharge should vary from month to month in the year; in other words,
does the greater frequency of a Sunday discharge characterize one part of
the year, that of a Tuesday another, and so on? In order to answer this
question I have re-calculated all my data, with results that are
graphically represented in Chart 13. These curves prove that the Sunday
maxima discharges occur in March and September, and the minima in June;
that the Monday maxima discharges occur in September, Friday in July, and
so on. Thus, there is a regular rhythm, according to which the days of
maximum discharge vary from one month of the year to another; and the
existence of this final rhythm appears to me very remarkable. I would
especially direct attention to the almost geometric symmetry of the Sunday
curve, and to the only less complete symmetry of the Thursday and Friday
curves. Certainly in these rhythms we have an ample field for farther
study and speculation.

I have now concluded my study of this fascinating inquiry; a study that is
necessarily incomplete, since it is based upon records furnished by one
individual only. The fact, however, that, even with so few observations,
and notwithstanding the consequently exaggerated disturbing influence of
minor irregularities, such remarkable and unexpected symmetry is evidenced
by these curves, only increases one's desire to have the opportunity of
handling a series of observations sufficiently numerous to render the
generalizations induced from them absolutely conclusive. I would again
appeal[384] to heads of colleges to assist this inquiry by enlisting in
its aid a band of students. If only one hundred students, living under
similar conditions, could be induced to keep such records with scrupulous
regularity for only twelve months, the results induced from such a series
of observations would be more than ten times as valuable as those which
have only been reached after ten years' observations on my part; and, if
other centuries of students in foreign and colonial colleges--e.g., in
Italy, India, Australia, and America--could be similarly enlisted in this
work, we should quickly obtain a series