Keeping a level head (and posterior)

Sit up straight at the back, and pay attention. Conceptual artist Catherine Graham is so concerned about the angle of people’s bottoms that she has created a garden bench entirely from spirit levels, supplied courtesy of Fisco Tools. The bench will be on display at venues throughout the summer. Building is rather hoping that this could spawn a whole new industry, and would like to enquire politely of Ms Graham if she could persuade Fisco to provide her with enough materials to create a spirit-level field, or even cricket pitch, for England to contest the Ashes on?