Try as we may our fence is always going to look a little awkward.The plumb-line does not hang down as we may perceive it to but pullsdirectly down toward the centre of the earth. Over such a greatdistance the ends of our fence will lean noticeably outward towardthe top and while the top of the fence is dead square the curvatureof the earth has our fence higher at each end than in the centre. Howsquare is square?