Permanent monuments made of concrete, granite, or some suitable equivalent and at least thirty-six inches in length and four inches square shall be so placed that all block corners, angle points, and points of curves can be accurately re-established. Iron pipes, at least twenty-four inches in length and with a diameter of three-fourths inches, shall be placed at all points on lot boundary lines where there is a change of direction and at all lot corners, unless a permanent monument is required at such point.
(Passed 5-23-74.)