Expert: Ralph Salier - 2/3/2011

Question
QUESTION: My husband and I discovered a heavy old looking metal sphere while cleaning out a garage while moving - left behind by the previous owner.  My husband seems convinced that it is a cannon ball...I on the other had doubt that based on some of what we have gleaned on line about cannon ball characterisitics.  As I understand solid shot cnanon balls have usually an equator line from the seam mold and are always even inches in diameter.  The marking on the ball though says "CU" which may lead to the conclusion that it is made of Copper and consequently likely a Mexican cannon ball.  We have found nothing in regards to characterisitics of Mexican cannon balls.  We would like to find out if it is indeed a cannon ball and if so if it is safe to have in the house.  Of course we are interested to learn it's age and original purpose.  Here is what we do know and some photos:

It is about 14" in circumference, 4 1/2" in diameter and weighs about 15 pounds.(See picture - 125)

It has a couple of key markings
1) Letters CU stamped on the side (See picture - 133)
2) 3 Circular markings (Two of which are next to each other  (See picture 130)
   a) A drilled hole about the 1/2" in diameter and goes about 1" inside (See picture -134)
   b) Another circle that looks like you need a key to unscrew? (See picture - 135)
   c) A 3rd circular marking  (See picture - 129)

One other thing to note is that if you scrape off the outside, it appears to be a shiny metal underneath, such as bronze, brass or copper.  You can sort of see this in picture 133.

Your expert help is much appreciated!

Annette

ANSWER: Hi Annette,

It is a bronze cannon ball, probably of French origin It is what is called a 15 pounder and would have carried a black powder charge.  The hole in the side may indicate that it was cleaned out to make it safe but the round area with the two holes is actually the fuse. Since this is intact, I would still be very careful with it.  Unless it is empty, it is not safe.  I would not keep it in the house and in fact, I would try to "give it away" to a museum and let them take on the "liability".  The circular markings pic did not come through (129) (134 and 125 (?) also did not come through)

If you would be kind enough to resend them to my email: rsalier@hotmail.com and put cannon ball in the subject line.

The CU (while this is the symbol for copper this is not what it means), is a manufacturer's mark and I'm not sure who made it.  With out seeing the other markings, I'm not sure what they may mean.  The drilled hole, as mentioned, may have been an attempt at getting to the hollow core to remove the black powder, a dangerous thing to do but perhaps they realized the danger and stopped.  

Do not drop it or put it near a heat source until you know for sure that it is safe.

---------- FOLLOW-UP ----------

QUESTION: Thank you very much the information.  I have to admit I am a little sick right now at the though that we have a live cannon ball in our home.  So next question - I don't know that we have a local museum to donate it to.  What would be the next option?  Call the autorities to come get it for a possible attempt at de-fusing it?  My husband of course thinks I am over reacting and wants desperately to have it defused so it can continue to hold a place of honor in his man cave:)

Thanks again!
Annette

Answer
Well, you can call the local police department to see if they have a bomb disposal team.  They may be able to remove the fuze and see what is inside.  If  they can open it, they will remove the black powder or other materials and return it to you at your request.  Ask them NOT to destroy it given its historical value and importance.  If they are unable to do so, perhaps the fire department or a local machine shop could continue the 1/2" hole very gently using a ceramic cutter to keep it from sparking and heavily cooled also very slowly done.

Baring this, the museum is the only other option and I'm sure that there is a museum some place with in a 200 mile radius.  To donate it will give you a nice tax write off.