I received an additional email from Norm.
After thought. The rear sight on a 10 pdr. Parrott goes to 10 degrees (2900 yards). The Federals in this situation are at a distinct disadvantage in that it will be hard for them to put shells into the fortification and the 10 pdr. will not have much effect on a well built earthwork. On the other hand the Confederates may be able to shoot into the Federal position from their higher elevation. I would still like to know what type of information would save the fortification mentioned. We might be able to find the documentation to match the specfic concern.
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