Whenever it shall be deemed necessary by an authority in connection with the exercise of its powers herein conferred to take or acquire any lands, structures or buildings or other rights, either in fee or as easements for any housing development or slum clearance, the authority may purchase the same directly or through its agent from the owner or owners thereof, or failing to agree with the owner or owners thereof, such authority may exercise the power of eminent domain in the manner provided for condemnation proceedings, in section eight, article one and sections nine and twelve, article two, chapter fifty-four of this code.