mistake would be fatal. The keys had slipped from the mattress

fell back, I directed an advance of my whole division, bringing up my

reserve regiments to occupy the crest of the hills; Colonel William

P. Carlin's brigade of Mitchell's division meanwhile moving forward

on my right to cover that flank. This advance pressed the enemy to

Perryville, but he retired in such good order that we gained nothing

but some favorable ground that enabled me to establish my batteries

in positions where they could again turn their attention to the

Confederates in front of McCook, whose critical condition was shortly