to the Virginia shore. Here I must remark that the President's House and Department buildings in its vicinity are but two and a half miles across the river from Arlington high ground, where a battery of bombs and heavy guns, if established, could destroy the city with comparatively a small force after destroying the bridges. The Capitol is only three and a half miles from the same height at Arlington, and at the Aqueduct the summits of the heights on the opposite shore are not over one mile from Georgetown.

With this view of the condition of our position, it is clear to my mind that the city is liable to be bombarded at the will of an enemy, unless we occupy the ground which he certainly would occupy id he had any such intention. I therefore recommend that the heights above mentioned be seized and secured by at least two strong redoubts, one commanding the Long Bridge and the other the Aqueduct, and that a body of men be there encamped to sustain the redoubts and give battle to the enemy if necessary. I have engineers maturing plans and reconnoitering further. It is quite probable that our troops assembled at Arlington would create much excitement in Virginia, yet, at the same time, if the enemy were to occupy the ground there a greater excitement would take place on our side, and it might be necessary to fight a battle to disadvantage.

I know not exactly how many troops we have at command. I presume the enemy might bring 10,000 troops into the field in a short time on such an occasion. I would not urge any premature movement in this quarter, yet one taken too late might cause much bloodshed.

All which is respectfully submitted.

JOS. K. F. MANSFIELD,

Colonel, Commanding Department.

P. S.-I should have said in the body of this report that I have been in consultation with my chief engineer, Major Barnard, in all these views, and his services have been and are very valuable to me.

J. K. F. M.,

Colonel, Commanding Department.

SPECIAL ORDERS,
HDQRS. DEP'T OF PENNSYLVANIA,

Numbers 24.
Philadelphia, May 3, 1861.

I. The line of communication with Washington City via Annapolis having been opened, commanding officers on the portion of the route in this department will permit passengers to pass to and from.

* * * * * * *

By order of Major-General Patterson.

F. J. PORTER,

Assistant Adjutant-General.

WASHINGTON, May 4, 1861.

Major-General PATTERSON, U. S. A., Commanding, &c.:

SIR: I am sorry to learn, unofficially, that your health has not been fully established. A few days of good weather will, I hope, accomplish that desirable object.

I have ordered the five companies of the Third Infantry, recently from Texas, now at New York, to Perryville to be united there, at Have de