BALTIMORE, MD., July 29, 1864.

Brigadier General E. B. TYLER,

Commanding First Separate Brigade:

GENERAL: Upon receipt of the telegram from General Halleck this p. m. at 4 o'clock, a courier was at once sent with a copy of the dispatch and instructions, a copy of which is inclosed herewith; subsequently General Wallace sent you two telegrams, copies of which are also inclosed. About two hours after the telegrams were sent it was discovered by the courier, who arrived from your headquarters, that there was no telegraph operator at the Relay House to-day, whereupon the original telegrams were given to him to send to you, and he was directed to inform you that One hundred and ninety-fifth Regiment Pennsylvania Militia and Rank's battery would be en route soon, to report to you at the Relay House. They will probably reach there before midnight. The regiment will be supplied with three days' rations and sixty rounds ammunition. The battery has caissons and limbers filled. The First Delaware Cavalry will march at once with three days' rations and 100 rounds ammunition per man and without forage, with instructions to get it on the road. The cavalry is ordered to march direct to Ridgeville and report to you there. Your attention is again called to the telegrams from General Halleck. Carry out his purposes as well as they can be understood. You will proceed with the battery and regiment to Ridgeville, from thence to Clarksburg, and cross over on the Rockville and Frederick pike with the double view of covering, if possible, the railroad and General Wright's wagon trains. The Delaware cavalry will report to you at Ridgeville, or follow you if you have left there. You will leave orders to that effect.

By command of Major-General Wallace:

SAMUEL B. LAWRENCE.

BALTIMORE, MD., July 29, 1864-7 p. m.

Brigadier General H. H. LOCKWOOD,

Commanding Third Separate Brigade:

GENERAL: You are hereby directed to put the following named troops en route at once, to report to Brigadier General E. B. Tyler, viz: One hundred and ninety-fifth Regiment Pennsylvania Militia, Battery H, Third Pennsylvania Artillery, and First Regiment Delaware Cavalry. The infantry and artillery will be sent by special train (which is now ready at Camden Station), to report to Brigadier-General Tyler at the Relay House. The infantry will be supplied with three days' ration and sixty rounds of ammunition per man. The artillery will fill the caissons and limbers with ammunition and take three days' rations and forage. The cavalry will march direct to Ridgeville, on the Baltimore and Ohio Railroad, and report to General Tyler there. Three days' rations will be issued to the command and 100 rounds of ammunition per man. They will obtain their forage on the road. The commanding officer of the cavalry will be directed to march rapidly.

By command of Major-General Wallace:

SAML. B. LAWRENCE,

Assistant Adjutant-General.