artillery; in the Shenandoah Valley, twelve regiments infantry, two brigades militia, one regiment cavalry, and seven companies artillery; and at Leesburg four regiments infantry, one regiment militia, five independent companies cavalry, and one company of artillery.

It is unnecessary for me to say that in the nature of the case, guarded as the rebels have ever been against the encroachment of spies, and vigilant as they have always been to prevent information of their designs, movements, or of their forces, going beyond their lines, it has been impossible, every by the use of every resource at our command, to ascertain with certainty the specific number and character of their forces. It may, therefore, safely be assumed that in so large an army as our information shows them to possess very much of its composition and very many of its forces have not been specifically ascertained, which, added to those already known, would largely increase their numbers and considerably swell its proportions.

The summary of the general estimate shows the forces of the rebel Army of the Potomac to be 150,000, as claimed by its officers and as sanctioned by the public belief, over 80,000 of which were stationed up to the time of evacuation at Manassas, Centreville, and vicinity, the remainder being within easy supporting distance. This fact is strongly supported by the statement of several supposed reliable persons, to the effect that 80,000 daily rations were issued to the forces at Manassas, Centreville, and vicinity, and by the well-sustained fact that the portions of the army in the Shenandoah Valley and the Lower Potomac each had their separate commissary department and received their supplies from sources entirely independent of the department at Manassas.

It will be seen by reference to several statements included in this report that the parties were engineers, conductors, & c., on the Manassas Gap Railroad, and that they testify under oath that their chance for information about the forces at Manassas and Centreville was the very best, and that the number stationed there up to about the time of evacuation was from 80,000 to 100,000. It is also shown by the statement of a refugee who resided near Fairfax Court-House that he learned from officers of the rebel army that the numbers of their forces at Manassas and Centreville were 75,000, and that 150,000 rations were drawn by the whole army.

All of which is respectfully submitted by your obedient servant,*

E. J. ALLEN. [ALLEN PINKERTON.]

EASTVILLE, VA., March 17, 1862.

A. STAGER:

Steamer just in from Fort Monroe. The line is sufficiently guarded by cavalry, and there is a guard night and day at the end of cable, but there is no field piece at Cape Charles to bring boats to, and being but 12 miles from Cape Henry, the blockade is easily run. when cable failed it was foggy. If not cut, it was damaged by anchors. If weather be calm, it will be underrun from both ends to-morrow (Tuesday). Boyle goes to Fort Monroe and I to Cape Charles. In event of interruption, we must rely principally on Fort Monroe. I will make a suggestion to-night to you in cipher.

W. H. HEISS.

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* Much the same as report of March 8, p. 736.

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