Artifact Corner: Battle of Plattsburgh Edition – Episode 6

Hi Everyone, and welcome back to our Battle of Plattsburgh Edition of Artifact Corner. Today we will be looking at a piece of copper sheeting, that has seen some serious damage. This piece is British, and has been hit by a cannon ball. As you can see there are a bunch of arrows covering this piece. These are called broad arrows.
The first use of a broad arrow was believed to be under King Edward III in the 1330’s. It was used by the King to establish his ownership over an item. In 1544 the broad arrow was officially used by the Office of Ordinance, and in 1597 it became the Board of Ordinance. In the 18th and early 19th Century, the broad arrow was used to mark everything from cannon balls to trees.
The British Navy valued the Eastern White Pine Trees in our area. They grow very tall and very straight, and are perfect for the masts of tall ships. The Navy therefore wanted as many Eastern White Pine trees as they could get, and would have trees marked with the Broad Arrow.
The other defining feature of this copper plate is the damage it sustained during the Battle of Plattsburgh. You can clearly see the impression of the ball’s shape, as it slammed into this piece of copper. Copper is a softer metal. Unworked copper is inherently soft, but if it is worked cold, it hardens. You can see the copper was curved by a crafts person. They likely did this cold, and therefore, this piece would have been work hardened. The cannon ball crushed through this easily.
An eight pound cannon ball can travel more than 1,000 feet per second and exert 124,335 foot pounds of force when striking an object. A cannon ball could go through over three feet of oak. Clearly a piece of copper sheet was no match for such force.
This remarkable artifact is an example of just how damaging cannon balls could be. Special thanks to the Lake Champlain Maritime Museum for allowing us access to their collections. This series could not have been possible without their generosity. You can learn more about them at Thanks so much for stopping by.

Special thanks to the Lake Champlain Maritime Museum for access to the LCAA collection and their collaboration in making this video possible. Visit them at

Music: Acoustic Breeze by Benjamin Tissot
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