PETERSBURG, VA., April 19, 1863.

Major General S. G. FRENCH, Commanding Department of Virginia:

GENERAL: I received your ordered of the 15th instant to abandon the line of signal from Fort Powhatan to Smithfield, at Hog Island, on the 16th instant at 2.30 p. m., and started at once for Ivor, where I found Captain Small had already preceded me. The work is very heavy along the line of railroad in erecting stations. Added to that, our resources are limited, and the line is not as efficient as it could be made had we glasses. We ought to have two glasses at each intermediate station. As it is now we have but one, and hard work to get them at that. My reconnaissance along the line of James River has been thorough and complete, and I think the line will be very serviceable when located to communicate to Smithfield should we keep a force there. I return in the morning to Ivor, and if the line is completed from there to General Longstreet's headquarters I will at once proceed to again locate posts on the James River as far as Boykins' old -(Fort Boykins), just above the mouth of Pagan Creek and about 3 miles Smithfield, which can be supplied by vedette, the woods and the character of the country generally precluding all possibility of running a line of signals direct to Smithfield unless we had undisputed possession of the river and the creek (by James River and Pagan Creek).

I find Hog Island a delightful pasturage for 1,000 horses, the clover now up it being ankle-deep; also herd-grass and timothy. Would it not be well enough to place a guard upon it and put our broken-down horses there to recuperate? All thrown Surry, Isle of Wight, Sussex, and Prince George where I have been ius scarce of forage and high.

Please send me written instruction what you desire me to do, and order me in detail what you desire should be done. The work of cutting out is very heavy, and I would most respectfully suggest that some company be ordered to report to me to act as guard to exposed posts and pioneers.

Your obedient servant,

J. F. MILLIGAN,

Captain, Commanding I. S. C. [Independent Signal Corps?].

HEADQUARTERS, April 20, 1863.

Major General SD. G. FRENCH, Commanding, &c.:

GENERAL: Your not per courier is received just after daydawn. Have a careful examination of the enemy made and let me know his dispositions as soon as possible. I shall be prepared to re-enforce you if the enemy is inclined to give battle below.

Most respectfully,
JAMES LONGSTREET,

Lieutenant-General, Commanding.

HEADQUARTERS, April 20, 1863.

Major-General FRENCH, Commanding, &c.:

GENERAL: From what Captain Clarke says of the creek on your right it would be much easier to make a ford there than a bridge. Please have it examined and attended to as soon as possible.

Yours, respectfully,

JAMES LONGSTREET,

Lieutenant-General, Commanding.