Jackson s gunners finally tipped their hand about noon. As Meade aligned his division for the attack, he pushed forward the 9th Pennsylvania Reserve Regiment as skirmishers. David G. McIntosh, commanding a Confederate artillery battery on Prospect Hill, watched breathlessly as the Union line approached. What an awful suspense these last moments are, he later recalled. The gun is charged, lanyard in hand, the gunner at the trail, ammunition heaped in piles nearby, waiting for the order to fire.
Minutes seem like hours.
One holds his breath and then breathes hard. But at last the moment comes. Eight hundred yards in front of the Confederate guns stood a lone tree. Southern artillerymen had precisely measured its distance and cut the time fuses on their exploding shells accordingly. By firing on the Union line, the Confederates had exposed the position of their guns to Union view.