The Director of Public Works shall place or cause to be placed, in some conspicuous position on the corner of each public way in the City, according to the direction and subject to the discretion of the City Manager as to the particular corner, a sign or other similar device indicating the name of each of the streets, avenues or other public ways as marked and shown on the plan set forth in this chapter, which plan is now on file in the office of the City Engineer, in such way as to indicate or designate them. No person shall remove, deface or injure any such sign or similar device.