A nail driven into the wall of the bank building at the upper edge of the foundation, on the Main Street side, at the corner of Main and Market Streets, is hereby established and declared to be the City Bench Mark, the elevation of this bench mark being four thousand seven hundred fifty seven and fifty-six hundredths feet (4757.56') above sea level. All elevations are referred to and figured from said City Bench Mark. (Ord. 25, 5-4-19)