Carl -
My take is that the plate sections are in "outside storage". Any backstop for shooting either bolts or shot would have included a dirt embankment behind the plates. The wood is likely cured/curing white oak that the navy yard used for the construction of gun carriages and other associated equipment. There are several sections of stacked wood in that photo that would challenge any one man's ability to toss into the fireplace - they are more akin to railroad ties than firewood it appears. The USN used coke in their casting furnaces - something the CSN had very limited access to in both quality and quantity. George Peacock, furnace master at the Selma Confederate Naval Gun Foundry & Ordnance Works (the official name) determined to use "pitch pine" in the reverberatory casting furnaces there. The result was a much hotter temperature than any reached by using coal, coke, wood, etc. That hotter flame produced a material containing far less carbon than iron produced elsewhere and thus the "best guns of their type produced anywhere on the earth" (or words to that effect).
Coincidentally and perhaps a primary causal factor in my initial confusion as to source, the covers of my copies of Ripley and the Miller "Navies" volume are nearly identical as to color.
