I have very few worries about the cannon 'walking'. In the photo you can see the wheels are bolted into 400 millimetres of concrete and peened over. Further, the trail is likewise permanently bolted to the fence post.
The next addition will be a stack of bowling balls in a brass monkey, all bolted down. Even so, I have good neighbours who look out for each other, this goes a long way to keeping things secure.
I must say that my postie started off pretty nervous about deliveries, particularly when bringing bills. She warmed up to it though when I demonstrated the ability to alter the height of the muzzle to suit her vehicle, she doesn't even have to step out of the car when bringing letters. I am tempted to add a recording of the 1812 Overture that plays when mail is inserted.
Merry Christmas to all.
