cavalry scouts kept patrolling this triangle no enemy could approach the line of road. A stronger force is required at Bull Run. Our men are at work, and except to have Bull Run Bridge passable by to-morrow morning. Without artillery we cannot defend the bridge against artillery. If the crossings of the Occoquan are guarded, Bull Run Bridge is our most exposed point. Please give a thought to the suggestions.

H. HAUPT.

WASHINGTON, D. C., August 31, 1862-5.40 p.m.

Major General GEORGE B. McCLELLAN:

I have arranged with General Tyler for guards to road and stations. He will strengthen the force at Bull Run Bridge and add a section of artillery. We still need about 500 cavalry between the railroad and the Occoquan. The troops you asked transportation for have not yet been sent. A regiment has just reported.

H. HAUPT.

McCLELLAN'S HEADQUARTERS,

August 31, 1862.

(Sent through Washington, September 1, 1862, 12.30 a.m.)

Major HALLER, Commanding at Fairfax Station:

It is reported that a large force of cavalry and three light batteries of the enemy were this afternoon near Fairfax Court-House. They may visit you to-night. Be ready for them. Infantry ought to handle cavalry anywhere in such a country as this. Be careful to secure your retreat, and in God's name do not be captured. Keep me constantly posted. If you find your communication with Fairfax Court-House irretrievably cut off, destroy the stores and make good your retreat to Alexandria. Communicate the same order to the detachment near you and presumably in your front. If possible fall back by the railroad, retreating only step by step, as you are forced to do so. Don't allow a mere cavalry raid to drive you off. Give ground only when you are absolutely forced to do so. Communicate by telegraph fully with Colonel Haupt, superintendent of railroad.

By order of General McClellan:

A. V. COLBURN,

Assistant Adjutant-General.

YORKTOWN, August 31, 1862.

Major General GEORGE B. McCLELLAN:

The following is a copy of a telegram just received from Captain Sawtelle. I ordered Couch's division to Aquia Creek:

FORT MONROE, August 31.

Major-General DIX:

The transports that took General Couch's division were not suitable for cavalry, and as many of these vessels were needed at once at Alexandria, it was deemed best to send Couch's division on them, more especially as it was thought it would not at all interfere with the loading of the cavalry. Since the cavalry commenced embarkating I have sent almost everything that could carry horses to Yorktown for that purpose. I shall continue to do so until Averell's cavalry is all embarked. The