Any public hall built under the provisions of this chapter shall be located by the township trustees so as to accommodate the greatest number of the resident taxpayers, and for such purpose the trustees may purchase land not to exceed in value five hundred dollars. They shall also have the power to join with the city authorities of any city within their borders and build and equip said building as a public hall or as a memorial building as provided in section 37.21 under such terms and conditions as may be mutually agreed upon.