ies of the north-west.

The American topographical engineers, as well as our own civil engineers
and savans, have accurately measured the heights and levels of the
lakes, which I have already given; but one very curious fact remains to
be noticed, and will prove that it is by no means a visionary idea that,
from the great island of Cuba, which must be an English outpost, if much
further annexation occurs, voyages will be made to bring the produce of
the West Indies and Spanish America into the heart of the United States
and Canada by the Mississippi and the rivers flowing into it, and by the
great lakes; so that a vessel, loading at Cuba, might perform a circuit
inland for many thousand miles, and return to her port _via_ Quebec.

From the Gulf of Mexico to the lowest summits of the ridge separating
the basin of the Mississippi from that of the St. Lawrence or great
lakes, the rise does not exceed six hundred feet, and the graduation of
the land has an average of not more than six inches to a mile in an
almost continuous inclined plane of six thousand miles. The Americans
have not lost sight of this natural assistance to form a communication
between the lakes and the Mississippi.

My attention has been drawn to the subsidence of the waters of the lakes
of Canada by the unusual lowness of Ontario, on the banks of which I
lived last year, and by reading the statement of the American writer
above quoted, as well as by the fact that in the Travels of Carver, one
of the first English navigators on these mediterraneans, who states that
a small ship of forty tons, in sailing from the head of Lake Michigan to
Detroit, was unable to pass over the St. Clair flats for want of water,
and that the usual way of passing them eighty years ago was in small
boats. What a useful thing it would have been, if any scientific
navigators or resident observers had registered the rise and fall of the
lakes in the years since Upper Canada came into our possession! An old
naval officer told me that it was really periodical; and it occurred
usually, that the greatest depression and elevation had intervals of
seven years. Lake Erie is evidently becoming more shallow constantly,
but not to any great or alarming degree; and shoals form, even in the
splendid roadstead of Kingston, within the memory of young inhabitants.
An American revenue vessel, pierced for, I believe, twenty-four guns,
and carrying an enormous Paixhan, grounded in the autumn of las