[Taylor Witt]

I was told by my grandfather that this object was found by his father while serving in WWI. The object was found at Fort Morgan (AKA Fort San Lorenzo) near the Chagres River (Panama Canal zone). He was also told that it was a 16th Century cannon ball and that it was made of bronze. The item has been cleaned to remove oxidation. Please see the photos at the following URL:

http://www.ofoto.com/ShareLandingSignin.jsp?U...e&Ux=0

(Be sure to click on "View Photos" as there are 3 photos total.)

Any help providing more specific information about this would be greatly appreciated. Thank you.

[Nathan Robinson]

Interesting. I have no idea. Is it a mace head? hm.

[Taylor Witt]

Thanks for the suggestion. I just found a great website about maces: http://otlichnik.tripod.com/medmace.html

The webpage on metal maces doesn't have any pictures that look like mine. Thanks again for the lead, I'll keep looking.

[David Quivey]

Dang, Taylor, that's an oddball, and no pun intended...
First glance at it didn't suggest a mace head to me, but rather a very old version of an impact-detonation cannon shell. If so, it's the oldest version of it's kind that I've ever seen!
Typical early cannon shells were ignited by a paper or cloth fuse, and therefore it was hard to control the time of explosion. These impact shells detonated when they hit something solid (ground or fortification) - the funny spikes are where the detonators are - if it had landed on one of those, it would have gone off.
I'm no expert, but I'm not sure if this technology was really around in the 16th century, but again, that's what it looks like to me! I've seen several examples like it, in cast iron, from much later eras.

[Patrick Kelly]

I was thinking exactly the same thing David. It appears to be some kind of early fragmintation shell. Or possibly some form of grapeshot, given the size.

[Sam Barris]

That looks exactly like a contact mine. It's impossible, of course, but that's what it looks like. I'm not sure about the fragmentation shell theory. It's possible, but I think those came around much later. Have you looked into any non-military possibilities? It might not be a weapon at all.

[Taylor Witt]

Gentlemen, thanks for the additional suggestions. I'll start looking into impact-detonation cannon shell theory a little more. A contact mine might explain the base of the shell. I haven't explored non-military uses. I wouldn't even know where to begin. I really appreciate everyone’s input. Thanks again.

[K Holsen]

It does look like an explosive mine or shell of some kind ..
I would be REALLY careful with that thing until you know exactly what it is. Consider having it xrayed ?
Also what is your basis for dating it to the 16th cen ? Not trying to slam your Grandfathers story of it but hearsay is not evidence of age. You might want to look into having it dated by a nearby lab. I'll see what I can find on dating metal objects that have been cleaned for you.

[Taylor Witt]

I also challenge the 16th Century claim. There's no basis other than what my grandfather was told by his father. I'd love to have it x-rayed and examined but am worried about the cost involved. My grandfather was worried it might explode just cleaning it, so he stopped. The majority of the oxidation has been removed as you can see by the photos. What type of lab would provide the x-ray and/or carbon dating? I live in Southern Connecticut and am very close (about 40 min) from New York City. I'm sure there is such a lab, if not in CT, then near NYC.

[Sam Barris]

It certainly looks like a contact mine, and the sea has the ability to devour metal, making something appear far older than it is, but the size of the casing makes that very unlikely. It would need enough explosive to breach the hull of a ship, which it doesn't have at that size. On the other hand, if it's older than 150 years or so, we're dealing with wooden ships as opposed to metal, so perhaps that's all they needed to punch through a wooden hull. A cannonball of some kind is far more likely, but that wouldn't explain the base, unless some collector 300 years ago decided to have it mounted for display or something...

And now an obligatory cautionary note. If you do get an x-ray, I'd tell them up front that it might be ordinance. I'm sure it isn't explosive anymore, but when we move ordinance from one part of our ship to another, we have to secure all of our radio and radar equipment for fear that the radiation might detonate something. But perhaps that's only a danger with modern ordinance.

[Petri Peltola]

I don't think we're looking at a finished object. I've done some casting and this thing looks like a bronze ball left (very) rough from the casting. The blob the ball is standing on in the first picture is where the metal was poured in (at least that's what it looks like to me) The things sticking out of the ball could be just channels for air and gasses to get out of the mold.
Maybe it's an unfinished bronze cannonball... That would be my guess based on the picture.
Why it was left the way it is, is an interesting question.

[David Quivey]

well, I'm no expert on old powders, but if it is a military object, and if it was some sort of explosive, then the black powder would be quite deteorated by now! I don't want to give any false alarm, but I've known old black powder cannon shells to explode on sharp contact - so no dropping!! I'm fairly sure an x-ray wouldn't cause black powder, even deteorated, to explode.

You might be right, Sam (if I'm reading correctly) about it being an underwater mine? That actually might explain the base, if it was mounted on a pole or like object and placed just above hull-line... would also explain why it is bronze.

[Brian M]

--It cannot be a shell fired from a cannon. The projections make that unlikely.
--It cannot be an incomplete casting, since you wouldn't have flues in every direction.
--The flange at the bottom looks like it is designed to be fixed to a surface or post.
--In pictures 1 and 2, one of the upper projections (the same one most likely) appears to resemble a nut and bolt.

Here's a suggestion: First weight the object. Then determine the total volume of the object by immersing it in water and seeing how much it displaces. Multiply the volume by the density of Bronze (8.8grams/cubic centimeter) to get the theoretical weight, and compare it to the measured weight. This will tell you if the object is hollow, and if so how much.

You know, it almost looks like a manifold of some sort...

Brian M

[Taylor Witt]

Great insight Brian. I'll figure the weight/volume out over the next couple days and re-post. Thanks for the tip.
-Taylor

[Sam Barris]

Great idea, Brian! Going all Archimedes on us. :-)

[Brian M]

I forgot to address the idea that it's a contact mine. It isn't. First, reliable contact exploders (called Herz Horns) were not invented until 1868. Second, there would not be so many on a mine. Third, a mine two inches across could not possibly contain enough blackpowder to damage even a wooden hulled ship. I doubt it would be for antipersonell use for similar reasons, plus why would you make it out of bronze?
I'd bet it's a piece of equipment left over from the various attempts at canal construction, or some bit of naval equipment.

Brian M

[Sam Barris]

If you look at my post, I acknowledged that it is impossible. First, I knew that the dates wouldn't match up. Second, in order to maintain positive buoyancy given its size, it would have to pretty much be paper thin, which it clearly isn't. My comment was that it looks remarkably like a contact mine. Or at least that it would if it were many times larger and a few hundred years younger. Honestly, I have no idea what it is, but it certainly makes for a fascinating discussion trying to figure it out. :-)

And now that we've established that the mysterious object is most certainly not a mine, I am compelled to inform you that the first drifting mine was employed in 1776. I give you the following taken directly from the British Royal Navy's history website:

"The first floating mine was designed and used during the American Revolution. In 1776 David Bushnell invented the "Bushnell's Keg." This primitive mine was composed of a watertight keg filled with black powder and a flintlock detonator which was suspended from a float. These kegs were placed in the Delaware River so that, it was hoped, they would float into British ships downriver."

Additionally, mines were used extensively during the American Civil War. Remember Farragut's immortal cry of, "Damn the torpedoes! Full speed ahead!"? He was talking about a Confederate minefield.

That said, I hereby desist and refrain from any and all further discussion of mines. :-)

[Tom Carr]

It doesnt look like a weapon to me. I think the fact that is was found in the Canal Zone points toward some sort of lost equipment from the constuction.

[Taylor Witt]

Those of you who have suggested that it may be a piece of equipment from the contruction of the canal,

Do you have any ideas as to what it is, or what it may have been used for?

[Sean Flynt]

I'm baffled about why any munition would be made of bronze, but I think it looks like a cross between the Civil War era Ketchum and Excelsior grenades. Here's some text on both:

"During the Civil War, two kinds of hand grenades were made, but they saw little use in combat. One of them, patented in August 1861, carried a percussion cap and an activating "plunger" that was not inserted until it was about to be thrown. Rated as effective at a distance of about twenty-six yards, this explosive piece was known by the name of its inventor, Ketchum.
A more sophisticated grenade, "the Excelsior," was developed in 1862 by W. W. Hanes. Its cast-iron shell held fourteen nipples, to each of which a percussion cap was attached before it was thrown. Hanes insisted, correctly, that at least one cap was sure to trigger an explosion. In practice, men trying to use his device often hit a cap accidentally and had a hand or arm blown off. As a result, it seems never to have been used in battle."

Here's a Ketchum. Look at the shape of the plunger. I'll try to find an image of the Excelsior, but, basically, they look just like the mystery object minus the thing that looks like a Ketchum-style plunger.