lying two or three days on 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 cooeperating 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 flats.

“When a work like this subserves the double purpose of military defence in times of war, and of promoting the interests of commerce between several of the States of the Union in time of peace, it would seem to have an increased claim to the attention of the General Government.  If any work of improvement can be considered national in its character, the improvement of St. Clair flats, in the manner proposed, may, it is submitted, justly claim to be placed in that category.”

The plan proposed by the United States Engineers for this improvement is to construct two parallel piers of about four thousand feet long, as a permanent protection to the channel-way, and to dredge out a channel between these piers, six hundred feet wide and twelve feet deep.  The cost of this work is estimated at about $533,000.  This may seem a large sum of money; but when it is considered that the value of the commerce which passed over these flats in the year 1855 was ascertained by Col.  Graham to be over two hundred and fifty millions of dollars, or considerably more than the whole exports of the Southern States for the year 1860, more than a million of dollars per day during the period of navigation, and that the increased charge on freights by reason of this obstruction is more than two millions of dollars per annum, which of course has to be paid by the producer, the investment of one quarter of that annual charge in a work which would do away with the tax might seem to be a measure of economy.