The elevation of the city datum shall be a plane measured 97.60 feet below the top of a bronze cap of an iron post set in concrete walk at the northeast corner of the County Court House yard in the city, said cap being marked as follows, “U.S. Geological B. M. Survey Prim. Trav. Sta. No. 15 ADJ 531 feet Elevation above Sea Datum”, the top of said cap being 529.411 feet above mean sea level.
(1960 Code, § 40-3-1)