Henri de Sourdis' Nautical Andirons

Origin
Launched in 1635, the French ship Couronne was the first major warship built by the French Navy. Intended to compete with the Dutch, it participated in several notable battles incuding the Battle of Guetaria. In 1639, Henri de Sourdis captained her on an expedition to Spain, though the Spaniard's powerful defences made the mission a failure. Scrapped between 1641 an 1645, the spare iron from the cannons was smelted down and remoulded into this set of andirons that was presented to de Sourdis a few short years before his death.

Effects
The effects of the andirons are barely noticable except under specific conditions. If used to hold back burning wood from a European source, the wood will become too damp to burn and will seep moisture. If near wood from Spain or nearby reigons, the wood will ignite and explode with the force of a cannon, causing severe damage to anything nearby.

It is possible that the cannons from the ship had this ability before being re-purposed.