these flats, everything taken from her into lighters, was unable, with
the powerful aid of steam and everything else she could bring into
service, to pass over; she was obliged to give her freight and
passengers to a smaller boat, abandon the trip, and return to Buffalo.
Other vessels have been compelled not only to take out all their
cargoes, but even their chains and anchors have been stripped from them,
before they could get over. To meet this difficulty as far as possible,
the commercial men around these lakes have imposed a tax upon their
shipping, to dredge out and deepen the channel through these flats."

Col. Graham, in one of his Reports to the Department, writes as follows
upon the importance of this improvement in a military point of view:--

"Since the opening of the Sault Ste. Marie Canal, the only obstacle to
the co-operation of armed fleets, which in time of war would be placed
upon Lakes Superior, Michigan, and Huron, with that which would be on
Lake Erie, is at St. Clair flats. That obstacle removed, and a depth
of channel of twelve feet obtained there, which might be increased to
sixteen or eighteen feet by dredging, war-steamers of the largest
class which would probably be placed on these lakes would have a free
navigation from Buffalo at the foot of Lake Erie to Fond du Lac of Lake
Superior.

"It would be very important that these fleets should have the power of
concentration, either wholly or in part, at certain important points now
rendered impracticable by these intervening flats. It would no doubt
often be important as a measure of naval tactics alone. It would as
often, again, be equally necessary in coöperating with our land-forces.
It might even become necessary to depend on the navy to transport our
land-forces rapidly from one point to another on different sides of the