"III. The Second and Sixth Brigades united will also push forward and
attack him in the rear by way of Centreville, protecting their own right
flanks and rear from the direction of Fairfax Station and Court House.

"IV. In the event of the defeat of the Enemy, the troops at Mitchell's
Ford and Stone Bridge, especially the Cavalry and Artillery, will join
in the pursuit, which will be conducted with vigor but unceasing
prudence, and continued until he shall have been driven beyond the
Potomac."

And it is not without interest to note Beauregard's subsequent
indorsement on the back of these Special Orders, that: "The plan of
attack prescribed within would have been executed, with modifications
affecting First and Fifth Brigades, to meet the attack upon Blackburn's
Ford, but for the expected coming of General Johnston's command, which
was known to be en route to join me on [Thursday] the 18th of July."

The knowledge thus possessed on Thursday, the 18th, by Beauregard, that
Johnston's Army is on its way to join him, is of infinite advantage to
the former. On the other hand, the complete ignorance, at this time, of
McDowell on this point,--and the further fact that he has been lulled
into a feeling of security on the subject, by General Scott's emphatic
assurance to him that "if Johnston joins Beauregard, he shall have
Patterson on his heels"--is a great disadvantage to the Union general.

Were McDowell now aware of the real Military situation, he would
unquestionably make an immediate attack, with the object of crushing
Beauregard before Johnston can effect a junction with him. It would
then be a mere matter of detail for the armies of McDowell, McClellan,