Hey everyone, this is the first post I've made in here and as a fellow historian I could use some help!
My dad was helping a friend clean out an old barn in Western Maryland when they found several cannon balls. I've attached the only picture he was able to get as they were cleaning everything out but they're 8" and about 70-75 lbs as best he knows. They're too rusted to read/make out any markings unfortunately.
The fact that they're round and don't seem to have a fuse seems to me to indicate possible naval use, and not mortar. Otherwise I have no idea and any additional help dating them would be great! They're going up for auction this Sunday, August 3rd.
Pic: http://i.imgur.com/yeaunnD.jpg
(Also, if this isn't the place for a post like this please feel free to point me in the right direction!)
I'm away from my artifact library at the moment, so I can't help with identification.
I'm sure the auction house that you're using has taken precautions, but with a post like this, I feel that a handling warning is called for.
Anyone who finds any cannonballs or other historic explosives should handle them with EXTREME caution, if at all. Many types of cannonballs contain explosive material, which can kill you long after the war they were created for has ended. Here is the news story of a relic collector who was killed handling a civil war cannonball.
I once had the bomb squad called out to a museum I was working for due to possible undefused explosives. They ended up taking part of a Civil War shell and blowing it up, as it still contained a signifigant amount of explosive, so they can still be quite dangerous.
Firstly, you might try /r/whatisthisthing as a specialized subreddit for this type of question.
I am not 100% sure that a large iron ball is necessarily a cannon shot, but if it is, I'll make several deductions. Firstly, a round shot is only for a smoothbore cannon. Later rifled cannon would use oblong projectiles. Secondly, 8-inch solid shot is very large. You are correct that only naval or siege guns would use such a large projectile.
So smoothbore cannon were produced up until and during the civil war, and very few coastal artillery were produced in the pre-war period the size of the large weapon you described, especially in the United States. Furthermore, It's unlikely to be from some pre-war weapon since not many were manufactured in peacetime, compared to the quantity produced for the war.
The most popular smoothbore Naval gun of the correct caliber would be something like an [8-inch Rodman] (http://en.wikipedia.org/wiki/Rodman_gun). [That projectile would weigh 65 pounds or so as described here] (http://www.civilwarartillery.com/hap/page33.htm) which is close enough to the estimate given to be plausible.
The main thing to do, is to confirm it's actually a cannon shot, and I can't help you there.
8" cannon (and mortars) were a thing during the CW, but I cannot find my books that have specific details on Civil War cannon to determine which cannon may have fired those balls.
