Upon completion of the assessment roll the secretary shall deliver the same to the district board and immediately give notice thereof and of the time the board of directors, acting as a board of equalization will meet to equalize assessments, by publication in a newspaper published in each of the counties comprising the district. The time fixed for the meeting shall not be less than twenty nor more than thirty days from the first publication of the notice, and in the meantime the assessment roll must remain in the office of the secretary for the inspection of all persons interested.