believing that your extensive acquaintance and close observation in that
region have put you in possession of facts which will enable you to
determine, with a degree of accuracy, the fluctuations of these waters,
and their present increased or diminished height, as well as to trace
some of the causes which have an influence in producing the results that
are experienced in the rise and fall of the lakes."

This rise and fall is found to be concurrent in volume and time in the
whole series of lake basins, and is not at all influenced by artificial
constructions. It is believed to be dependent on the annual fall of
water, on the water sheds of the lake basins, and the comparative
evaporation caused by the annual diffusion of solar heat during the same
periods. Nothing less than the accumulation of facts to illustrate these
general laws, for considerable periods of time, will, it is believed,
philosophically account for the phenomena. Tables of solar heat, rain
guages, and scientific measures, to determine the fall of snow over the
large continental era of the whole series of basins, are, therefore, the
scientific means that should be employed before we can theorize
properly. As to periodical rises, actually observed, they are believed
to be the very measure of these phenomena, namely, the fall of
atmospheric moisture, and the concurrent intensity of solar heat
_between the unknown periods of the rise_.

The fluctuations in Lake Michigan and the Straits of Michilimackinack
are capable of being accounted for on a separate theory, namely, the
theory of lake winds.

_4th July_. Letters from Detroit show that the political agitations
respecting Canada still continue. One correspondent remarks: "The fourth
of July passed off here with more _apparent_ patriotic feeling than I
have ever known before. Canada is still across the river--the
_pat-riots_ have not yet removed any part of it; they are, however,
still busy."

Another says: "Times look troublesome, but I am in hopes that it will
all blow over and peace continue, which should be the earnest wish of
every Christian."

_23d_. Public business calling me to Washington, I left Mackinack late
in June, and, pushing day and night, reached that city on the 9th of
July. The day of my arrival was a hot one, and, during our temporary
stop in the cars between the Relay House and Bladensburg, some
pickpocket eased me of my pocket-book, containing a treasury-note for
$50, about $60