There are actually a lot of artillery related accounts in the book. The one that comes to my mind is the portion titled "Pine Mountain--Death of General Leonidas Polk. "While looking at them with his field glass, a solid shot from the Federal guns struck him in his left breast, passing through his body and through his heart. I saw him while the infirmary corps were bringing him off the field. He was as white as a piece of marble, and the most remarkable thing about him was, that not a drop of blood was ever seen to come out of the place through which the cannon ball had passed."
A couple of pages later he writes about the "Dead Angle" at Kennesaw, Georgia: "...the Federal line opened upon us, and for more than an hour they poured their solid and chain shot, grape and shrapnel right upon this salient point, defended by our regiment alone...."
In the section about Murfreesboro he wrote: "As I went back to the field hospital, I overtook another man walking along. I do not know to what regiment he belonged, but I remember of first noticing that his left arm was entirely gone. His face was white as a sheet. The breast and sleeve of his coat had been torn away, and I could see the frazzled end of his shirt sleeve, which appeared to be sucked into the wound. I looked at it pretty close, and I said 'Great God!' for I could see his heart throb, and the respiration of his lungs. I was filled with wonder and horror at the sight. He was walking along, when all of a sudden he dropped down and died without a struggle or a groan."
There's a ton of artillery related accounts in Co Aytch that have remained in my memory since reading it that I remember where they are in the book years later. It's such a fascinating account of the war.