Upon the presentation to the commissioners court of a petition signed by twenty-five of the resident property taxpayers of any proposed district praying for the establishment thereof within the county, and setting forth the boundaries, and accompanied by a map thereof, the general nature of the improvements proposed, and an estimate of the probable cost thereof, and praying for the issuance of bonds and levy of a tax in payment thereof, and designating a name for such district which shall include the name of the county; and accompanied by the affidavit of the petitioners stating that they are resident property taxpayers of such county; the court shall set the same down for a hearing at a regular or called session, not less than thirty nor more than sixty days thereafter.