der and Bush River bridges, but that they are not subject to his orders, nor does he know to whom they report. The general commanding directs, therefore, that you ascertain from the officers in commanding of said boats what are their instructions, and whether we may rely upon them to assist in the protection of the bridges.

SAML. B. LAWRENCE,

Assistant Adjutant-General.

HEADQUARTERS MIDDLE DEPARTMENT,
Baltimore, Md., July 26, 1864.

Brigadier General H. H. LOCKWOOD,

Commanding Third Separate Brigade:

GENERAL: I am directed by Major-General Wallace to acknowledge receipt of your communication of this date, in reply to letter from these headquarters making inquiries concerning the guards at the various bridges on the Philadelphia, Wilmington and Baltimore Railroad. In reply, I am directed to instruct you to place a guard of at least twenty-five men, under a careful commissioned officer, at Back River bridge. In addition to the guard at the Gunpowder and Bush River bridges, as reported by you, viz, eighty-four officers and men, you will add one company of infantry, which will be sufficient for the present.

You will use the boats to patrol, as directed in letter from these headquarters of 25th instant; you will also adopt such other means of defense for the bridges as in your judgment may be necessary. It is considered important that the utmost precautions be taken to prevent a recurrence of the recent successful attempts of the enemy to destroy the communications. An effort will be made to have a gun-boat stationed at the Gunpowder and Bush River bridges. It is believed that the guard at Havre de Grace, as reported by you, is ample for the protection of the boats and landings there.

You will please report to these headquarters the name of the commanding officer at Havre de Grace. Lieutenant-Colonel French was ordered by Major-General Halleck to assume command of the troops at that point. It appears, however, that Colonel French has returned to Philadelphia, as he says he was only ordered to take command of troops temporarily at Havre de Grace, and all such troops having been ordered away, he is, therefore, relieved.

I am, general, very respectfully, your obedient servant,

SAML. B. LAWRENCE,

Assistant Adjutant-General.

FREDERICK, July 26, 1864.

Major-General WALLACE:

I left Martinsburg yesterday about 3. 30 p. m. with some rebel prisoners. When I left our troops were still in possession of the town; cannot say positively in regard to enemy's numbers; in military circles they estimate from 20,000 to 40,000. I saw tow of their lines, which I would estimate at 25,000; cannot say what was behind. Our wagon train safe. When I left I saw a passenger train, and one engine and tender, also one train of soldiers going toward Cumberland from Martinsburg.

DANL. LINK,

Captain.