To see a cannon is a symbol of extreme emotion.
This is also a sign that someone is threatening you in a rather unsatisfactory manner. It is a symbol associated with an overreaction to a conflict or a petty argument. The actual position of the canon represents the time period of when you are likely to encounter this scenario. It can also be a sign that you may be overreacting to a situation in your current life.
The size of the cannon is equally important. A large cannon is an indication that other people may get involved in this conflict. Make sure that this conflict allows you to control things in the distant future. This symbol is nothing to be scared of since in the long-term it is a positive omen. It's a clear indication telling you to that you should trust in yourself.
In your teacup you could have:
Meaning of the cannon in your tea leaf reading...