The city reserves the right at any time to place upon any of the poles, that are not or may hereafter be erected, the wires of its fire alarm, telegraph or any wires for its use, and to attach any fire alarm boxes to those poles without payment of any sum therefor, and the Board of Public Works and Safety shall have the right to have the location of those poles and wires changed when, in their judgement, the public interest of the city demands it; and should any telegraph, telephone or electric light company discontinue operations at any time, the companies will be required forthwith to remove all their poles and wires from the streets and alleys of the city.
('71 Code, § 100.43)