For the convenience of the public and for the further purpose of furnishing a ready means of ascertaining the appropriate number of any house, building or place of business, required by this chapter to be numbered, the city engineer shall prepare a plat, map or diagram of the city showing the proper number for every lot, half lot or twenty-five feet aforesaid, which map shall be hung in the office of the city clerk for public inspection. (Prior code § 5-47).