the Pike, and 600 yards
West of the bridge, have caught sight of Tyler's Union blue-jackets.
Those of the Rebel gunners whose eyes are directed to the North-East,
soon see, nearly a mile away, up the gradual slope, a puff of blue
smoke. Immediately the bang of a solitary rifle cannon is heard, and
the scream of a rifled shot as it passes over their heads. At
intervals, until past 9 A.M., that piece and others in the same
position, keep hammering away at the Rebel left, under Evans, at Stone
Bridge.

The Rebel response to this cannonade, is very feeble. McDowell observes
this. He suspects there has been a weakening of the Enemy's force at
the bridge, in order to strengthen his right for some purpose. And what
can that purpose be, but to throw his augmented right upon our left, at
Blackburn's Ford, and so, along the ridge-road, upon Centreville? Thus
McDowell guesses, and guesses well. To be in readiness to protect his
own left and rear, by reenforcing Miles's Division, at Centreville and
along the ridge to Blackburn's Ford, he temporarily holds back Howard's
Brigade of Heintzelman's Division at the point where the cross-road to
Sudley Springs Ford-along which Hunter's Division, followed by the
Brigades of Franklin and Wilcox, of Heintzelman's Division, have already
gone-intersects the Warrenton Pike.

It is 9 o'clock. Beauregard, as yet unaware of McDowell's new plan,
sends an order to Ewell, on his right, to hold himself ready "to take
the offensive, at a moment's notice,"--and directing that Ewell be
supported in his advance, toward Sangster's cross-roads and the rear of
Centreville, by Holmes's Brigade. In accordance with that order, Ewell,
who is "at Union Mills and its neighborhood," gets his brigade ready,
and Holmes moves up to his support. After waiting two hours, Ewell
receives another order, for both Ewell and Holmes "to resume their
places." Something must have occurred since 9 o'clock, to defeat
Beauregard's plan of attack on Centreville--with all its glorious
consequences! What can it be? We shall see.

While Tyler's Artillery has been cannonading the Rebel left, under
Evans, at Stone Bridge,--fully impressed with the prevailing Union
belief that the bridge is not only protected by strong masked batteries,
heavy supports of Infantry, and by abatis as well as other defenses, but
is also mined and ready to be blown up at the approach of our troops,
when in reality the bridge is not mined, and t