Notice in writing required to be given by said Director may be served by any person over the age of 21 years, and the fact of such service may be verified by the oath of the person making it. Such oath may be taken before said Director or the acting Secretary of said Department of Public Works.
All notices and resolutions required by this Article to be published shall be published in the official newspaper.
All notices herein required to be served, whether by delivering, mailing or posting, may be so served by any citizen of the age of 21 years or over, and his affidavit thereof shall be prima facie evidence of such service. The affidavit of the publisher of the local newspaper or his clerk, of the publication of any notice required in this Article to be published, shall be prima facie evidence of such publishing.