Was There A Third Shot?

Source

"It was a pleasant hazy Indian summer day and so warm that I was carrying my overcoat on my arm. When the line squatted down I folded the coat into a compact bundle and placed it on the edge of the bank in rear of my company and sat on it, with my feet in the shallow ditch. By craning my neck, I could look over our low parapet. The battle was opened by a rebel cannon, which, unnoticed by us, had taken position on a wooded knoll off our left front over towards the river. The first shot from this cannon flew a little high, directly over the angle where I was sitting. The second shot, dropped short and I was thinking with a good deal of discomfort that the third shot would get the exact range and would probably lift some of us out of that angle; but before it came our line had opened fire on the approaching rebel line and I became so much interested in that fire that I never knew whether there was a third shot from the cannon."