The point at which I propose to force a passage of the Tallahatchee is now covered by one of their field-works, as I discovered by a personal reconnaissance yesterday. The recent rains have made the roads by which we pass from the point we now occupy to the river below their fort almost impassable.

But for a heavy rain last night, we should have put under cover tonight a battery of four 10-pounder Parrotts, to silence their battery and prevent the construction of additional works at the point above referred to. This must now be postponed at least another day.

I have written to General Prentiss, at Helena, to send forward, if he has it, material for a bridge 300 feet long, and this morning dispatched a boat up the river for the purpose of having a saw-mill examined, and, if possible, put in running order, to get out such lumber as we require. My fear is that our troops on their way down injured and destroyed the machinery to such an extent that the mill cannot be put in repair in time for our purposes.

Yesterday four 24-pounder siege guns arrived-two of our own and two of rebel manufacture. Of the latter, one only can be used, but it is proposed to mount on the carriage of the other a 30-pounder Parrott, taken from one of the gunboats.

I am, general, very respectfully,&c.,

I. F. QUINBY,

Brigadier-General, Commanding.

Major General J. B. McPHERSON,

Commanding SEVENTEENTH Army Corps.

Numbers 8.

Reports of Lieutenant Commander Watson Smith, U. S. Navy.

UNITED STATES Mississippi SQUADRON,

March 12, 1863.

GENERAL: Lieutenant Commander Watson Smith informs me that he has but a month's supply of provisions. I am anxious to supply him, but have no vessel. Can you furnish me with a small steamer that will go without fail through the Pass and join the vessels and troops you have send him by same conveyance.

Very respectfully, your obedient servant,

DAVID D. PORTER,

Acting Rear-Admiral, Commanding Mississippi Squadron. .

Major General U. S. GRANT,

Commanding Army of the Mississippi.

[Inclosure Number 1.]

U. S. S. RATTLER,

Coldwater, March 3, 1863.

SIR: We are advancing but slowly. This stream is not so much wider or clearer than the Pass as to make much difference in either speed or the amount of damage inflicted on these vessels.