What is the purpose of Cannons in the game?

What is the purpose of Cannons in the game? What do they actually do? How can they be made to be active in a positive way? Are they linked to Hidden Stats? If so which ones..

The reason why I am asking is that no one seems to know exactly what their Primary purpose is.

Please Kindly explain as am very Confused as to why a supposedly important item seems to do absolutely nothing within the game Kind Regards Neil