The Plow Cannon

Lowering the Bar posts about an 1862 patent for the "Plow Cannon."

There really isn't much more I can say, but here is part of the invention's description:

The object of our invention is to produce a plow equal, if not superior, in point of strength and lightness as to that implement as ordinarily made, and at the same time to combine in its construction the elements of light ordnance, so that when the occasion offers it may do valuable service in the capacity of both implements.

Unfortunately, I don't think that this device was ever in common use, so I doubt that it would receive much protection under the Second Amendment.