The said Mayor is empowered to authorize any such company or corporation owning and operating lines of street poles and wires on March 3, 1905, or thereafter and any alley poles or alley-pole line or housetop wires within the said District and outside of the limits described in § 34-1921.01 to continue to maintain the same, with such repairs and renewals as may be necessary to keep them in good order and condition of repair, and to add thereto such poles and wires as may be necessary for their telegraphic purposes.