Farrington began a forced march of 10 miles upon Ponchatoula. A locomotive 1 mile below the village gave notice of our approach, which could not be concealed, and ran northward, giving the alarm at the village, and thence to Camp Moore, for re-enforcements. We met on entering Ponchatoula a discharge of canister at 70 yuards from a light battery, in charging which Captain Thornton fell severely wounded. His company, then under Lieutentant Hight, re-enforced Captain Farrington's first platoon, that had gained a position on the enemy's right, to which Lieutentant Coan, with the second platoon of that company, took a position, under partial cover, on the left of the enemy's line. From these positions our men poured in so deliberate and destructive a fire that the enemy was driven from the field, the artillery galloping away, followed by the infantry, on a road through the forest, in a northwesterly direction. We then set fire to a train of upwards of 20 cars, laden with cotton, sugar, molasses, &c., took the papers from the post and telegraph offices (destroying the apparatus of the latter), and General Jeff. Thompson, sword, spurs, bridle, &c., from his quarters in the hotel. The sword was presented to him by so-called "Memphis patriots."

A written document was obtained, which showed the rebel force at that point to consist of 300 troops of the Tenth Arkansas Regiment, one company of Home Guards, and one company of artillery, with six pieces. I had, however, received reliable information that the enemy's force was a week previous only 200 infantry and no artillery . The re-enforcement had taken place at a subsequent date. Our force engaged amounted to but 112 men. We left, of killed, wounded, and missing (exclusive of those who have since come in among these last the gallant Thornton), 10 men at Ponchatoula. Surgeon Avery, Ninth Connecticut Volunteers, with his attendant, voluntarily remained with the wounded, but the former has since returned. We brought in 11 men more or less severely wounded. One fatal case of sunstroke occurred on board the steamer. Our return from Ponchatoula was necessarily along the railroad, through a swamp, and on which there is no cover for troops and it was therefore impossible to bring off those of our men who were most severely wounded, as they would be exposed for a long distance to the fire of the artillery, which, with horses attached, would be brought back upon the line of the road as soon as we should have left the village. It did so return at the signal of the inhabitants, but, though actively served, did us no harm. Surgeon Avery reports 20 of the enemy killed.

Captains Thorton and Farrington and the officers and men of their respective commands, though nearly exhausted by the march (2 miles of which was over an open trestle work), in the heat of the day, behaved nobly in the fight. Captains Pickering and Winter, after a very rapid march, for which they are entitled to much credit, came up after we had left the village, covered our rear, and assisted in bringing in the wounded. Lieutenants Martin, Allen, and Finegass, and Commander Buchanan, U. S. Navy, who accompanied the expedition, rendered important services, and their gallantry during the action deserves special mention.

I have the honor to be, general, very respectfully, your obedient servant,

GEO. C. STRONG,

Assistant Adjutant-General.

Major General BENJAMIN F. BUTLER,

Commanding Department of the Gulf.