In case the corporation of the city desires at any time to put in operation any fire alarm or police, telegraph or telephone system, it reserves to itself the right to use the top, or a space near the top of any and all telegraph, telephone or electric light poles, free of expense, for the purpose of attaching wires thereto for use of the fire alarm or police telephone or telegraph; and the granting of any franchise to any person to erect poles for any of the purposes indicated in this section shall be with the above reservation of privilege and right to the city. (Prior code § 8-4-6)