The centre of gravity is the point in the structure where all of the weight can be thought to act. If movement of the structure occurs, it will pivot around fixed points at the base and the position of the centre of gravity is crucial. When the centre of gravity is moved outside the vertical supports, then the structure will fall because there is a leverage effect acting on the structure. The following link will open a new browser window. CENTRE OF GRAVITY INTERACTIVE You will need to have a Flash Player plug-in to view these diagrams. If you do not have a Flash Player, please download it now.