A family argument over whether the Earth is flat or round became so heated that one of the participants threw a propane cylinder onto a campfire, prompting an intervention by firefighters.

The dispute over a question most considered resolved centuries ago boiled over around 10:30 p.m. Monday at St. Lawrence Park in Brockville, Ont.

Police said a 56-year-old Brockville man was at a campsite with his son and his son's girlfriend when the woman began insisting that the Earth is flat.

The older man insisted the Earth is round.

It's not clear if anyone at the campfire put forth the argument that the Earth's equatorial bulge makes it not perfectly round, but instead a shape known as an oblate spheroid.

Nevertheless, police said the man became so enraged he began throwing objects into the campfire, including a propane cylinder.

Brockville firefighters were called to put out the campfire. By the time police arrived at the scene, the man had left.

Brockville police are looking for the man and say they expect to charge him with mischief.