That at the time set for the hearing of the petition, as provided in the next preceding section, it shall be the duty of the board of county commissioners to first ascertain and determine whether notice has been given of the time of hearing as required by this act, and, if it shall be determined that such notice has been given, to make a declaration and finding of that fact and cause the same to be entered upon its records, and thereupon to hear all persons in favor or opposed to granting the prayer of said petition and all other evidence that it may desire to hear for the purpose of ascertaining whether such petition contains the proper number of signers possessing the qualifications prescribed by this act, and whether the statements in said petition are true; and if upon such hearing it shall be found that such petition is in conformity to the requirements of this act, and that the allegations thereof are true, then such board of county commissioners shall make a finding and decision to that effect, and shall thereupon immediately declare the territory described in the petition to constitute a public corporation, and the inhabitants within such bounds to be incorporated as a drainage district under the name of “The ____ drainage district, _____ county, Kansas” (inserting the name designated in the petition and the name of the proper county), and thenceforth the said territory and the inhabitants residing therein and their successors shall constitute a body politic and corporate under said corporate name, and shall have perpetual succession.