They have 2 locomotives, 2 passenger cars, and 12 platform cars; 3 of the latter we have here. I captured here two 8-inch columbiads in good order, with the carriages complete; 90 new Enfield rifles, and 25 prisoners.

Our approach was sudden and rapid, and on arriving in sight two companies of infantry were here busily engaged in getting the two large guns on the cars. They ran at once and scattered into the woods. My infantry, which had been landed below and sent to their rear, caught all except those who took the Des Are road and concealed themselves in the woods. My cavalry landed at once and penetrated the country 7 miles on the Little Rock road, until the mud and water became utterly impassable.

I started a gunboat and some infantry early this morning up the river to Des Arc, where I hope to capture a train engaged in transportation supplies to Little Rock, and, perhaps, a quantity of corn, oats, and other forage.

Hindman, with his forces, is at Little Rock, arriving there last Monday. General Henry [E.] McCulloch is believed to be at Pine Bluff.

General Hawes, with three regiments of cavalry and six pieces of light artillery, was ordered to re-enforce Post Arkansas, and started last Sunday on a forced march, but only got as far as Hick's railroad station, within 3 miles of Brownsville, and is supposed now to be on the west side of the Arkansas.

All the forces of the enemy, except two, or, possibly three, companies of bushwackers are now west of the Arkansas River, and the people are running their stock and negroes toward Texas; and it is quite sure their many do not intend to fight at Little Rock if they are not able to check our forces at Pine Bluff, which they do not seem to think they can do.

If it were possible for me to get cavalry across this low, marshy country to Brownsville and Little Rock, I would start them at once; but this is utterly impracticable. The snow is now 4 or 5 inches deep, and melting, and the Grand Prairie is a vast sheet of water, precluding the least of getting across the Little Rock with infantry, artillery, or cavalry, until the rainy season is over, and the country, which is a vast level plain, dries off. If it were possible to get cavalry across this prairie, the enemy would cut the bridges over the Bayou Meto, and other smaller streams, now swollen to overflow, and stop us there.

I am greatly at loss to know how I am to get my 1,200 cavalry back to Helena, or out to the Mississippi River. Since they arrived at Clarendon, the rain and snow has fallen to such an extent as to fill the vast bayous,lakes,and little rivers to such proportions as to make it a serious question whether I shall be able to save the horses, as I have not sufficient transportation to take them out by water, and forage cannot be had,owing to like causes, except by the river. If General Fisk is taken from me, I will be compelled to leave this point and go below, as I shall be so crippled as to leave me utterly powerless. I have been crippled by the withdrawal of one regiment to New Madrid, and one at Memphis. I then, unexpectedly, was required to leave a garrison at Helena of 2,000 men. I have left a regiment of 800 infantry,two companies of cavalry,and a battery at Saint Charles, and now I am called on to part with my largest brigade, at least 3,500 strong, making in all a draft of 6,400 men on me, leaving me less than 5,000 effective men. I will be down at once to see you.

I have not heard a word from General Curtis about parting with the force you ask, but if any immediate move is to be made to Vicksburg,