Some reflections based on Calef's description from post #2 above.
Attached map shows estimated positions of Calef's battery. The six guns spent the night of June 30 in the hollow as shown, according to a drawing prepared by K. P. Scott of Company H, 1st Pennsylvania. That location happens to be about 600 yards from the position taken by the right and center sections on the morning of July 1, which is the same distance mentioned by Calef in his official report.
The Scott drawing has the three sections placed as indicated on my map (right under Lt. Roder, center under 1Sgt Newman and left under Sgt Pergel). While posting his right and center sections, Calef writes that he noticed Generals Buford and Reynolds with their staffs on the pike, and received detailed instructions from Buford on how to precisely place his three sections. When Calef went to the left to place Sgt Pergel's section south of Herbst woods, Lt. Roder opened fired with his left piece. Calef rode back to direct his right and center sections for a time.
Later on, Calef was returning to Pergel's section when he encountered Buford again, as he memorably describes. Continuing on, Calef states that just as he arrived at Pergel's section, he saw Archer's brigade advancing from "McPherson woods" ... "not over a thousand yards distant." Those woods we call "Herbst woods," however, as shown on the map, given the distance quoted by Calef, Archer must have just emerged from the woods on Herr's ridge; I figure the time was about 9:55 a.m. At that moment, the Iron Brigade was still on Seminary Ridge, but was soon hastened westward for their epic encounter. In the meantime, we know Archer was slowed up a bit by thick vegetation encountered at Willoughby Run. I'm guessing Pergel's section was withdrawn at about the time Archer reached the Run and thus passed by Meredith's oncoming lead regiments, although Calef's account expresses the sequence somewhat differently.
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